HYB25D256400AE-8 [INFINEON]
DDR DRAM, 64MX4, 0.8ns, CMOS, PDSO66, 0.400 INCH, PLASTIC, TSOP2-66;型号: | HYB25D256400AE-8 |
厂家: | Infineon |
描述: | DDR DRAM, 64MX4, 0.8ns, CMOS, PDSO66, 0.400 INCH, PLASTIC, TSOP2-66 动态存储器 双倍数据速率 光电二极管 |
文件: | 总75页 (文件大小:1179K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
HYB25D256400/800AT
256-MBit Double Data Rata SDRAM
Features
• Data mask (DM) for write data
CAS Latency and Frequency
• DLL aligns DQ and DQS transitions with CK
transitions.
Maximum Operating Frequency (MHz)
CAS Latency
DDR266A
-7
DDR200
-8
• Commands entered on each positive CK edge;
data and data mask referenced to both edges of
DQS
2
133
143
100
125
2.5
• Burst lengths: 2, 4, or 8
• Double data rate architecture: two data transfers
per clock cycle
• CAS Latency: 2, 2.5
• Bidirectional data strobe (DQS) is transmitted
and received with data, to be used in capturing
data at the receiver
• Auto Precharge option for each burst access
• Auto Refresh and Self Refresh Modes
• 7.8 µs Maximum Average Periodic Refresh
• DQS is edge-aligned with data for reads and is
center-aligned with data for writes
Interval
• 2.5V (SSTL_2 compatible) I/O
• Differential clock inputs (CK and CK)
• V
= 2.5V ± 0.2V / V = 2.5V ± 0.2V
DD
DDQ
• Four internal banks for concurrent operation
• TSOP66 package
Description
The 256Mb DDR SDRAM is a high-speed CMOS,
dynamic random-access memory containing
268,435,456 bits. It is internally configured as a
quad-bank DRAM.
Read and write accesses to the DDR SDRAM are
burst oriented; accesses start at a selected location
and continue for a programmed number of locations
in a programmed sequence. Accesses begin with
the registration of an Active command, which is then
followed by a Read or Write command. The address
bits registered coincident with the Active command
are used to select the bank and row to be accessed.
The address bits registered coincident with the
Read or Write command are used to select the bank
and the starting column location for the burst
access.
The 256Mb DDR SDRAM uses a double-data-rate
architecture to achieve high-speed operation. The
double data rate architecture is essentially a 2n
prefetch architecture with an interface designed to
transfer two data words per clock cycle at the I/O
pins. A single read or write access for the 256Mb
DDR SDRAM effectively consists of a single 2n-bit
wide, one clock cycle data transfer at the internal
DRAM core and two corresponding n-bit wide, one-
half-clock-cycle data transfers at the I/O pins.
The DDR SDRAM provides for programmable Read
or Write burst lengths of 2, 4 or 8 locations. An Auto
Precharge function may be enabled to provide a
self-timed row precharge that is initiated at the end
of the burst access.
A bidirectional data strobe (DQS) is transmitted
externally, along with data, for use in data capture at
the receiver. DQS is a strobe transmitted by the
DDR SDRAM during Reads and by the memory
controller during Writes. DQS is edge-aligned with
data for Reads and center-aligned with data for
Writes.
As with standard SDRAMs, the pipelined, multibank
architecture of DDR SDRAMs allows for concurrent
operation, thereby providing high effective band-
width by hiding row precharge and activation time.
The 256Mb DDR SDRAM operates from a differen-
tial clock (CK and CK; the crossing of CK going
HIGH and CK going LOW is referred to as the posi-
tive edge of CK). Commands (address and control
signals) are registered at every positive edge of CK.
Input data is registered on both edges of DQS, and
output data is referenced to both edges of DQS, as
well as to both edges of CK.
An auto refresh mode is provided along with a
power-saving power-down mode. All inputs are
compatible with the JEDEC Standard for SSTL_2.
All outputs are SSTL_2, Class II compatible.
Note: The functionality described and the timing
specifications included in this data sheet are for the
DLL Enabled mode of operation.
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Page 1 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Pin Configuration
VDD
NC
VSS
VSS
NC
VDD
DQ0
VDDQ
NC
1
2
3
4
5
66
65
64
63
62
DQ7
VSSQ
NC
VDDQ
NC
VSSQ
NC
DQ0
DQ6
DQ3
DQ1
VSSQ
NC
VDDQ
NC
VDDQ
NC
VSSQ
NC
6
61
60
59
58
57
7
NC
DQ5
VSSQ
NC
NC
DQ2
VDDQ
NC
8
VDDQ
NC
VSSQ
NC
9
10
DQ3
DQ1
VSSQ
NC
DQ4
DQ2
11
12
56
55
VSSQ
NC
VDDQ
VDDQ
NC
NC
13
14
15
16
17
18
19
20
54
53
52
51
50
49
48
47
NC
NC
NC
NC
VSSQ
DQS
NC
VSSQ
DQS
NC
VDDQ
NC
VDDQ
NC
NC
VDD
NU
NC
VDD
NU
VREF
VSS
DM*
VREF
VSS
DM*
NC
NC
WE
WE
CK
CK
CK
CK
21
22
23
46
45
44
CAS
CAS
RAS
RAS
CKE
CKE
CS
NC
CS
NC
NC
NC
24
25
43
42
A12
A12
BA0
BA1
BA0
BA1
A11
A9
A11
A9
26
27
28
29
41
40
39
38
A8
A8
A10/AP
A10/AP
A7
A7
A0
A1
A2
A0
A1
A2
A6
A5
A6
A5
30
31
37
36
A3
A3
A4
A4
32
33
35
34
VDD
VSS
VSS
VDD
66-pin Plastic TSOP-II 400mil
32Mb x 8
64Mb x 4
I
Column Address Table
Organization
Column Address
A0-A9, A11
A0-A9
64Mb x 4
32Mb x 8
* DM is internally loaded to match DQ and DQS identically.
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HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Input/Output Functional Description
Symbol
Type
Function
Clock: CK and CK are differential clock inputs. All address and control input signals are sam-
pled on the crossing of the positive edge of CK and negative edge of CK. Output (read) data
is referenced to the crossings of CK and CK (both directions of crossing).
CK, CK
Input
Clock Enable: CKE HIGH activates, and CKE Low deactivates, internal clock signals and
device input buffers and output drivers. Taking CKE Low provides Precharge Power-Down
and Self Refresh operation (all banks idle), or Active Power-Down (row Active in any bank).
CKE is synchronous for power down entry and exit, and for self refresh entry. CKE is asyn-
chronous for self refresh exit. CKE must be maintained high throughout read and write
accesses. Input buffers, excluding CK, CK and CKE are disabled during power-down. Input
buffers, excluding CKE, are disabled during self refresh.
CKE
Input
Chip Select: All commands are masked when CS is registered HIGH. CS provides for exter-
nal bank selection on systems with multiple banks. CS is considered part of the command
code. The standard pinout includes one CS pin.
CS
Input
Input
RAS, CAS, WE
Command Inputs: RAS, CAS and WE (along with CS) define the command being entered.
Input Data Mask: DM is an input mask signal for write data. Input data is masked when DM
is sampled HIGH coincident with that input data during a Write access. DM is sampled on
both edges of DQS. Although DM pins are input only, the DM loading matches the DQ and
DQS loading.
DM
Input
Input
Bank Address Inputs: BA0 and BA1 define to which bank an Active, Read, Write or Pre-
charge command is being applied. BA0 and BA1 also determines if the mode register or
extended mode register is to be accessed during a MRS or EMRS cycle.
BA0, BA1
Address Inputs: Provide the row address for Active commands, and the column address
and Auto Precharge bit for Read/Write commands, to select one location out of the memory
array in the respective bank. A10 is sampled during a Precharge command to determine
whether the Precharge applies to one bank (A10 LOW) or all banks (A10 HIGH). If only one
bank is to be precharged, the bank is selected by BA0, BA1. The address inputs also provide
the op-code during a Mode Register Set command.
A0 - A12
Input
DQ
Input/Output
Input/Output
Data Input/Output: Data bus.
Data Strobe: Output with read data, input with write data. Edge-aligned with read data, cen-
tered in write data. Used to capture write data.
DQS
NC
NU
No Connect: No internal electrical connection is present.
Don’t use
VDDQ
VSSQ
VDD
Supply
Supply
Supply
Supply
Supply
DQ Power Supply: 2.5V ± 0.2V.
DQ Ground
Power Supply: 2.5V ± 0.2V.
Ground
VSS
VREF
SSTL_2 reference voltage: (VDDQ / 2)
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HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Ordering Information
Part Numbers
Standard Versions
CAS
Latency
Clock
(MHz)
CAS
Latency
Clock
(MHz)
Speed
Org.
Package
HYB25D256400AT-7
HYB25D256800AT-7
HYB25D256400AT-8
HYB25D256800AT-8
x 4
x 8
x 4
x 8
143
125
133
DDR266A
2.5
2
66 pin TSOP-II
100
DDR200
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Page 4 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Block Diagram (64Mb x 4)
CKE
CK
CK
CS
WE
CAS
RAS
Bank3
Bank2
Bank1
CK, CK
DLL
Mode
13
Registers
8192
Bank0
Memory
Array
Data
15
13
(8192 x 1024 x 8)
4
4
4
8
Sense Amplifiers
1
DQS
Generator
DQ0-DQ3,
DM
COL0
Mask
DQS
Input
Register
1
I/O Gating
DM Mask Logic
8
2
DQS
1
1
A0-A12,
BA0, BA1
Write
15
1
FIFO
1
&
8
2
8
1024
(x8)
2
Drivers
4
4
4
4
4
clk
clk
Column
Decoder
in
out
Data
10
COL0
CK,
CK
Column-Address
Counter/Latch
11
COL0
1
1
Note: This Functional Block Diagram is intended to facilitate user understanding of the operation of
the device; it does not represent an actual circuit implementation.
Note: DM is a unidirectional signal (input only), but is internally loaded to match the load of the bidi-
rectional DQ and DQS signals.
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HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Block Diagram (32Mb x 8)
CKE
CK
CK
CS
WE
CAS
RAS
Bank3
Bank2
Bank1
CK, CK
DLL
Mode
Registers
13
8192
Bank0
Memory
Array
Data
1
13
15
(8192 x 512 x 16)
8
8
8
16
Sense Amplifiers
DQS
Generator
DQ0-DQ7,
DM
COL0
Mask
DQS
Input
Register
1
I/O Gating
DM Mask Logic
16
2
DQS
1
A0-A12,
BA0, BA1
Write
15
1
8
FIFO
1
1
&
16
2
2
512
(x16)
Drivers
8
8
8
8
16
clk
clk
Column
Decoder
in
out
Data
9
COL0
CK,
CK
Column-Address
Counter/Latch
10
COL0
1
1
Note: This Functional Block Diagram is intended to facilitate user understanding of the operation of
the device; it does not represent an actual circuit implementation.
Note: DM is a unidirectional signal (input only), but is internally loaded to match the load of the bidi-
rectional DQ and DQS signals.
10/01
Page 6 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Functional Description
The 256Mb DDR SDRAM is a high-speed CMOS, dynamic random-access memory containing 268, 435, 456
bits. The 256Mb DDR SDRAM is internally configured as a quad-bank DRAM.
The 256Mb DDR SDRAM uses a double-data-rate architecture to achieve high-speed operation. The double-
data-rate architecture is essentially a 2n prefetch architecture, with an interface designed to transfer two data
words per clock cycle at the I/O pins. A single read or write access for the 256Mb DDR SDRAM consists of a
single 2n-bit wide, one clock cycle data transfer at the internal DRAM core and two corresponding n-bit wide,
one-half clock cycle data transfers at the I/O pins.
Read and write accesses to the DDR SDRAM are burst oriented; accesses start at a selected location and
continue for a programmed number of locations in a programmed sequence. Accesses begin with the regis-
tration of an Active command, which is then followed by a Read or Write command. The address bits regis-
tered coincident with the Active command are used to select the bank and row to be accessed (BA0, BA1
select the bank; A0-A12 select the row). The address bits registered coincident with the Read or Write com-
mand are used to select the starting column location for the burst access.
Prior to normal operation, the DDR SDRAM must be initialized. The following sections provide detailed infor-
mation covering device initialization, register definition, command descriptions and device operation.
Initialization
DDR SDRAMs must be powered up and initialized in a predefined manner. Operational procedures other
than those specified may result in undefined operation. The following two conditions must be met:
No power sequencing is specified during power up or power down given the following criteria:
V
V
and V
meets the specification
are driven from a single power converter output
DD
DDQ
TT
A minimum resistance of 42 ohms limits the input current from the V supply into any pin and V
TT
REF
tracks V
/2
DDQ
or
The following relationship must be followed:
V
V
V
is driven after or with V such that V
< V + 0.3 V
DDQ
DD
DDQ DD
is driven after or with V
such that V < V
+ 0.3V
TT
DDQ
TT
DDQ
is driven after or with V
such that V
< V
+ 0.3V
DDQ
REF
DDQ
REF
The DQ and DQS outputs are in the High-Z state, where they remain until driven in normal operation (by a
read access). After all power supply and reference voltages are stable, and the clock is stable, the DDR
SDRAM requires a 200µs delay prior to applying an executable command.
Once the 200µs delay has been satisfied, a Deselect or NOP command should be applied, and CKE should
be brought HIGH. Following the NOP command, a Precharge ALL command should be applied. Next a Mode
Register Set command should be issued for the Extended Mode Register, to enable the DLL, then a Mode
Register Set command should be issued for the Mode Register, to reset the DLL, and to program the operat-
ing parameters. 200 clock cycles are required between the DLL reset and any executable command. During
the 200 cyalces of clock for DLL locking, a Delect or NOP command must be appied. After the 200 clock
cycles, a Precharge ALL command should be applied, placing the device in the “all banks idle” state.
Once in the idle state, two AUTO REFRESH cycles must be performed. Additionally, a Mode Register Set
command for the Mode Register, with the reset DLL bit deactivated (i.e. to program operating parameters
without resetting the DLL) must be performed. Following these cycles, the DDR SDRAM is ready for normal
operation.
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HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Register Definition
Mode Register
The Mode Register is used to define the specific mode of operation of the DDR SDRAM. This definition
includes the selection of a burst length, a burst type, a CAS latency, and an operating mode. The Mode Reg-
ister is programmed via the Mode Register Set command (with BA0 = 0 and BA1 = 0) and retains the stored
information until it is programmed again or the device loses power (except for bit A8, which is self-clearing).
Mode Register bits A0-A2 specify the burst length, A3 specifies the type of burst (sequential or interleaved),
A4-A6 specify the CAS latency, and A7-A12 specify the operating mode.
The Mode Register must be loaded when all banks are idle, and the controller must wait the specified time
before initiating the subsequent operation. Violating either of these requirements results in unspecified opera-
tion.
Burst Length
Read and write accesses to the DDR SDRAM are burst oriented, with the burst length being programmable.
The burst length determines the maximum number of column locations that can be accessed for a given
Read or Write command. Burst lengths of 2, 4, or 8 locations are available for both the sequential and the
interleaved burst types.
Reserved states should not be used, as unknown operation or incompatibility with future versions may result.
When a Read or Write command is issued, a block of columns equal to the burst length is effectively
selected. All accesses for that burst take place within this block, meaning that the burst wraps within the block
if a boundary is reached. The block is uniquely selected by A1-Ai when the burst length is set to two, by A2-Ai
when the burst length is set to four and by A3-Ai when the burst length is set to eight (where Ai is the most
significant column address bit for a given configuration). The remaining (least significant) address bit(s) is
(are) used to select the starting location within the block. The programmed burst length applies to both Read
and Write bursts.
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HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Mode Register Operation
BA1 BA0 A12
A11 A10 A9
A8
A7
A6
A5
A4
A3
BT
A2
A1
A0
Address Bus
0*
0*
CAS Latency
Burst Length
Mode Register
Operating Mode
A12 - A9
0
A8
0
A7
0
A6 - A0
Valid
Operating Mode
A3
Burst Type
Sequential
Interleave
Normal operation
Do not reset DLL
0
1
Normal operation
in DLL Reset
0
1
0
Valid
0
0
1
Reserved
Reserved
−
−
−
CAS Latency
Burst Length
A6
A5
0
A4
0
Latency
Reserved
Reserved
2
A2
0
A1
0
A0
0
Burst Length
0
0
0
0
1
1
1
1
Reserved
2
0
1
0
0
1
1
0
0
1
0
4
1
0
0
1
1
1
0
1
0
1
Reserved
Reserved
Reserved
2.5
0
1
1
1
1
1
0
0
1
1
1
0
1
0
1
8
Reserved
Reserved
Reserved
Reserved
Reserved
VS** Vendor Specific
* BA0 and BA1 must be 0, 0 to select the Mode Register
(vs. the Extended Mode Register).
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HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Burst Definition
Starting Column Address
Order of Accesses Within a Burst
Burst Length
A2
A1
A0
Type = Sequential
Type = Interleaved
0-1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0-1
2
4
1-0
1-0
0
0
1
1
0
0
1
1
0
0
1
1
0-1-2-3
0-1-2-3
1-2-3-0
1-0-3-2
2-3-0-1
2-3-0-1
3-0-1-2
3-2-1-0
0
0
0
0
1
1
1
1
0-1-2-3-4-5-6-7
1-2-3-4-5-6-7-0
2-3-4-5-6-7-0-1
3-4-5-6-7-0-1-2
4-5-6-7-0-1-2-3
5-6-7-0-1-2-3-4
6-7-0-1-2-3-4-5
7-0-1-2-3-4-5-6
0-1-2-3-4-5-6-7
1-0-3-2-5-4-7-6
2-3-0-1-6-7-4-5
3-2-1-0-7-6-5-4
4-5-6-7-0-1-2-3
5-4-7-6-1-0-3-2
6-7-4-5-2-3-0-1
7-6-5-4-3-2-1-0
8
Notes:
1. For a burst length of two, A1-Ai selects the two-data-element block; A0 selects the first access within the
block.
2. For a burst length of four, A2-Ai selects the four-data-element block; A0-A1 selects the first access within
the block.
3. For a burst length of eight, A3-Ai selects the eight-data- element block; A0-A2 selects the first access
within the block.
4. Whenever a boundary of the block is reached within a given sequence above, the following access wraps
within the block.
Burst Type
Accesses within a given burst may be programmed to be either sequential or interleaved; this is referred to as
the burst type and is selected via bit A3. The ordering of accesses within a burst is determined by the burst
length, the burst type and the starting column address, as shown in Burst Definition on page 10.
Read Latency
The Read latency, or CAS latency, is the delay, in clock cycles, between the registration of a Read command
and the availability of the first burst of output data. The latency can be programmed 2 or 2.5 clocks.
If a Read command is registered at clock edge n, and the latency is m clocks, the data is available nominally
coincident with clock edge n + m.
Reserved states should not be used as unknown operation or incompatibility with future versions may result.
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HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Operating Mode
The normal operating mode is selected by issuing a Mode Register Set Command with bits A7-A12 to zero,
and bits A0-A6 set to the desired values. A DLL reset is initiated by issuing a Mode Register Set command
with bits A7 and A9-A12 each set to zero, bit A8 set to one, and bits A0-A6 set to the desired values. A Mode
Register Set command issued to reset the DLL should always be followed by a Mode Register Set command
to select normal operating mode.
All other combinations of values for A7-A12 are reserved for future use and/or test modes. Test modes and
reserved states should not be used as unknown operation or incompatibility with future versions may result.
Required CAS Latencies
CAS Latency = 2, BL = 4
CK
CK
Read
NOP
NOP
NOP
NOP
NOP
Command
CL=2
DQS
DQ
CAS Latency = 2.5, BL = 4
CK
CK
Read
NOP
NOP
NOP
NOP
NOP
Command
CL=2.5
DQS
DQ
Shown with nominal tAC, tDQSCK, and tDQSQ
.
Don’t Care
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HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Extended Mode Register
The Extended Mode Register controls functions beyond those controlled by the Mode Register; these addi-
tional functions include DLL enable/disable and output drive strength selection (for future design versions, not
implement in this product). These functions are controlled via the bits shown in the Extended Mode Register
Definition. The Extended Mode Register is programmed via the Mode Register Set command (with BA0 = 1
and BA1 = 0) and retains the stored information until it is programmed again or the device loses power. The
Extended Mode Register must be loaded when all banks are idle, and the controller must wait the specified
time before initiating any subsequent operation. Violating either of these requirements result in unspecified
operation.
DLL Enable/Disable
The DLL must be enabled for normal operation. DLL enable is required during power up initialization, and
upon returning to normal operation after having disabled the DLL for the purpose of debug or evaluation. The
DLL is automatically disabled when entering self refresh operation and is automatically re-enabled upon exit
of self refresh operation. Any time the DLL is enabled, 200 clock cycles must occur before a Read command
can be issued. This is the reason 200 clock cycles must occur before issuing a Read or Write command upon
exit of self refresh operation.
Output Drive Strength
The normal drive strength for all outputs is specified to be SSTL_2, Class II. I-V curves for the normal drive
strength are included in this document.
An option for weak driver support intended for lighter load and/or point-to-point environments and will be
implemented in future versions of this product. Selection of the weak driver option will reduce the output drive
strength by ~ 55% of that of the normal strength.
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HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Extended Mode Register Definition
A12
A8
A7
A6
A5
A4
A3
A2
A1
A0
BA1 BA0
A11
A10
A9
Address Bus
Extended
Mode Register
0**
0*
1*
Operating Mode
DS
DLL
Drive Strength
An - A3
0
A2 - A0
Valid
Operating Mode
A1
0
Drive Strength
Normal
Normal Operation
All other states
Reserved
−
−
1
reserved
A0
0
DLL
Enable
Disable
1
* BA0 and BA1 must be 1, 0 to select the Extended Mode Register
(vs. the base Mode Register)
0** has to programmed to 0
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HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Commands
CommandsDeselect
The Deselect function prevents new commands from being executed by the DDR SDRAM. The DDR SDRAM
is effectively deselected. Operations already in progress are not affected.
No Operation (NOP)
The No Operation (NOP) command is used to perform a NOP to a DDR SDRAM. This prevents unwanted
commands from being registered during idle or wait states. Operations already in progress are not affected.
Mode Register Set
The mode registers are loaded via inputs A0-A12, BA0 and BA1. See mode register descriptions in the Reg-
ister Definition section. The Mode Register Set command can only be issued when all banks are idle and no
bursts are in progress. A subsequent executable command cannot be issued until t
is met.
MRD
Active
The Active command is used to open (or activate) a row in a particular bank for a subsequent access. The
value on the BA0, BA1 inputs selects the bank, and the address provided on inputs A0-A12 selects the row.
This row remains active (or open) for accesses until a Precharge (or Read or Write with Auto Precharge) is
issued to that bank. A Precharge (or Read or Write with Auto Precharge) command must be issued and com-
pleted before opening a different row in the same bank.
Read
The Read command is used to initiate a burst read access to an active (open) row. The value on the BA0,
BA1 inputs selects the bank, and the address provided on inputs A0-Ai, Aj (where [i = 8, j = don’t care] for
x16, [i = 9, j = don’t care] for x8 and [i = 9, j = 11] for x4) selects the starting column location. The value on
input A10 determines whether or not Auto Precharge is used. If Auto Precharge is selected, the row being
accessed is precharged at the end of the Read burst; if Auto Precharge is not selected, the row remains open
for subsequent accesses.
Write
The Write command is used to initiate a burst write access to an active (open) row. The value on the BA0,
BA1 inputs selects the bank, and the address provided on inputs A0-Ai, Aj (where [i = 9, j = don’t care] for x8;
where [i = 9, j = 11] for x4) selects the starting column location. The value on input A10 determines whether or
not Auto Precharge is used. If Auto Precharge is selected, the row being accessed is precharged at the end
of the Write burst; if Auto Precharge is not selected, the row remains open for subsequent accesses. Input
data appearing on the DQs is written to the memory array subject to the DM input logic level appearing coin-
cident with the data. If a given DM signal is registered low, the corresponding data is written to memory; if the
DM signal is registered high, the corresponding data inputs are ignored, and a Write is not executed to that
byte/column location.
Precharge
The Precharge command is used to deactivate (close) the open row in a particular bank or the open row(s) in
all banks. The bank(s) will be available for a subsequent row access a specified time (t ) after the Precharge
RP
command is issued. Input A10 determines whether one or all banks are to be precharged, and in the case
where only one bank is to be precharged, inputs BA0, BA1 select the bank. Otherwise BA0, BA1 are treated
as “Don’t Care.” Once a bank has been precharged, it is in the idle state and must be activated prior to any
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Read or Write commands being issued to that bank. A precharge command is treated as a NOP if there is no
open row in that bank, or if the previously open row is already in the process of precharging.
Auto Precharge
Auto Precharge is a feature which performs the same individual-bank precharge functions described above,
but without requiring an explicit command. This is accomplished by using A10 to enable Auto Precharge in
conjunction with a specific Read or Write command. A precharge of the bank/row that is addressed with the
Read or Write command is automatically performed upon completion of the Read or Write burst. Auto Pre-
charge is nonpersistent in that it is either enabled or disabled for each individual Read or Write command.
Auto Precharge ensures that the precharge is initiated at the earliest valid stage within a burst. The user must
not issue another command to the same bank until the precharge (t ) is completed. This is determined as if
RP
an explicit Precharge command was issued at the earliest possible time, as described for each burst type in
the Operation section of this data sheet.
Burst Terminate
The Burst Terminate command is used to truncate read bursts (with Auto Precharge disabled). The most re-
cently registered Read command prior to the Burst Terminate command is truncated, as shown in the Opera-
tion section of this data sheet.
Auto Refresh
Auto Refresh is used during normal operation of the DDR SDRAM and is analogous to CAS Before RAS
(CBR) Refresh in previous DRAM types. This command is nonpersistent, so it must be issued each time a
refresh is required.
The refresh addressing is generated by the internal refresh controller. This makes the address bits “Don’t
Care” during an Auto Refresh command. The 256Mb DDR SDRAM requires Auto Refresh cycles at an aver-
age periodic interval of 7.8 µs (maximum).
To allow for improved efficiency in scheduling and switching between tasks, some flexibility in the absolute
refresh interval is provided. A maximum of eight Auto Refresh commands can be posted in the system,
meaning that the maximum absolute interval between any Auto Refresh command and the next Auto Refresh
command is 9 * 7.8 µs (70.2µs). This maximum absolute interval is short enough to allow for DLL updates
internal to the DDR SDRAM to be restricted to Auto Refresh cycles, without allowing too much drift in t
between updates.
AC
Self Refresh
The Self Refresh command can be used to retain data in the DDR SDRAM, even if the rest of the system is
powered down. When in the self refresh mode, the DDR SDRAM retains data without external clocking. The
Self Refresh command is initiated as an Auto Refresh command coincident with CKE transitioning low. The
DLL is automatically disabled upon entering Self Refresh, and is automatically enabled upon exiting Self
Refresh (200 clock cycles must then occur before a Read command can be issued). Input signals except
CKE (low) are “Don’t Care” during Self Refresh operation.
The procedure for exiting self refresh requires a sequence of commands. CK (and CK) must be stable prior to
CKE returning high. Once CKE is high, the SDRAM must have NOP commands issued for t
because
XSNR
time is required for the completion of any internal refresh in progress. A simple algorithm for meeting both
refresh and DLL requirements is to apply NOPs for 200 clock cycles before applying any other command.
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Truth Table 1a: Commands
Name (Function)
CS
H
L
RAS CAS
WE
X
Address
X
MNE
NOP
NOP
ACT
Notes
1, 9
Deselect (Nop)
X
H
L
X
H
H
L
No Operation (Nop)
H
H
H
L
X
1, 9
Active (Select Bank And Activate Row)
Read (Select Bank And Column, And Start Read Burst)
Write (Select Bank And Column, And Start Write Burst)
Burst Terminate
L
Bank/Row
Bank/Col
Bank/Col
X
1, 3
L
H
H
H
L
Read
Write
BST
1, 4
L
L
1, 4
L
H
H
L
L
1, 8
Precharge (Deactivate Row In Bank Or Banks)
Auto Refresh Or Self Refresh (Enter Self Refresh Mode)
Mode Register Set
L
L
Code
X
PRE
1, 5
L
L
H
L
AR / SR
MRS
1, 6, 7
1, 2
L
L
L
Op-Code
1. CKE is HIGH for all commands shown except Self Refresh.
2. BA0, BA1 select either the Base or the Extended Mode Register (BA0 = 0, BA1 = 0 selects Mode Register; BA0 = 1, BA1 = 0
selects Extended Mode Register; other combinations of BA0-BA1 are reserved; A0-A12 provide the op-code to be written to the
selected Mode Register.)
3. BA0-BA1 provide bank address and A0-A12 provide row address.
4. BA0, BA1 provide bank address; A0-Ai provide column address (where i = 9 for x8 and 9, 11 for x4); A10 HIGH enables the Auto
Precharge feature (nonpersistent), A10 LOW disables the Auto Precharge feature.
5. A10 LOW: BA0, BA1 determine which bank is precharged.
A10 HIGH: all banks are precharged and BA0, BA1 are “Don’t Care.”
6. This command is AUTO REFRESH if CKE is HIGH; Self Refresh if CKE is LOW.
7. Internal refresh counter controls row and bank addressing; all inputs and I/Os are “Don’t Care” except for CKE.
8. Applies only to read bursts with Auto Precharge disabled; this command is undefined (and should not be used) for read bursts with
Auto Precharge enabled or for write bursts
9. Deselect and NOP are functionally interchangeable.
Truth Table 1b: DM Operation
Name (Function)
Write Enable
Write Inhibit
DM
L
DQs
Valid
X
Notes
1
1
H
1. Used to mask write data; provided coincident with the
corresponding data.
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Operations
Bank/Row Activation
Before any Read or Write commands can be issued to a bank within the DDR SDRAM, a row in that bank
must be “opened” (activated). This is accomplished via the Active command and addresses A0-A12, BA0 and
BA1 (see Activating a Specific Row in a Specific Bank), which decode and select both the bank and the row
to be activated. After opening a row (issuing an Active command), a Read or Write command may be issued
to that row, subject to the t
specification. A subsequent Active command to a different row in the same
RCD
bank can only be issued after the previous active row has been “closed” (precharged). The minimum time
interval between successive Active commands to the same bank is defined by t . A subsequent Active com-
RC
mand to another bank can be issued while the first bank is being accessed, which results in a reduction of
total row-access overhead. The minimum time interval between successive Active commands to different
banks is defined by t
.
RRD
Activating a Specific Row in a Specific Bank
CK
CK
HIGH
CKE
CS
RAS
CAS
WE
RA = row address.
BA = bank address.
RA
BA
A0-A12
BA0, BA1
Don’t Care
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tRCD and tRRD Definition
CK
CK
RD/WR
ACT
NOP
ACT
NOP
NOP
NOP
NOP
Command
ROW
BA x
ROW
BA y
COL
BA y
A0-A12
BA0, BA1
tRRD
tRCD
Don’t Care
Reads
Subsequent to programming the mode register with CAS latency, burst type, and burst length, Read bursts
are initiated with a Read command, as shown on Read Command on page 19.
The starting column and bank addresses are provided with the Read command and Auto Precharge is either
enabled or disabled for that burst access. If Auto Precharge is enabled, the row that is accessed starts pre-
charge at the completion of the burst, provided t
has been satisfied. For the generic Read commands
RAS
used in the following illustrations, Auto Precharge is disabled.
During Read bursts, the valid data-out element from the starting column address is available following the
CAS latency after the Read command. Each subsequent data-out element is valid nominally at the next posi-
tive or negative clock edge (i.e. at the next crossing of CK and CK). Read Burst: CAS Latencies (Burst Length
= 4) on page 20 shows general timing for each supported CAS latency setting. DQS is driven by the DDR
SDRAM along with output data. The initial low state on DQS is known as the read preamble; the low state
coincident with the last data-out element is known as the read postamble. Upon completion of a burst,
assuming no other commands have been initiated, the DQs goes High-Z. Data from any Read burst may be
concatenated with or truncated with data from a subsequent Read command. In either case, a continuous
flow of data can be maintained. The first data element from the new burst follows either the last element of a
completed burst or the last desired data element of a longer burst which is being truncated. The new Read
command should be issued x cycles after the first Read command, where x equals the number of desired
data element pairs (pairs are required by the 2n prefetch architecture). This is shown on Consecutive Read
Bursts: CAS Latencies (Burst Length = 4 or 8) on page 21. A Read command can be initiated on any clock
cycle following a previous Read command. Nonconsecutive Read data is illustrated on Non-Consecutive
Read Bursts: CAS Latencies (Burst Length = 4) on page 22. Full-speed Random Read Accesses: CAS
Latencies (Burst Length = 2, 4 or 8) within a page (or pages) can be performed as shown on page 23.
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Read Command
CK
CK
HIGH
CKE
CS
RAS
CAS
WE
x4: A0-A9, A11
x8: A0-A9
CA
EN AP
A10
DIS AP
BA
CA = column address
BA = bank address
EN AP = enable Auto Precharge
DIS AP = disable Auto Precharge
BA0, BA1
Don’t Care
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Read Burst: CAS Latencies (Burst Length = 4)
CAS Latency = 2
CK
CK
Read
NOP
NOP
NOP
NOP
NOP
Command
Address
BA a,COL n
CL=2
DQS
DQ
DOa-n
CAS Latency = 2.5
CK
CK
Read
NOP
NOP
NOP
NOP
NOP
Command
Address
BA a,COL n
CL=2.5
DQS
DQ
DOa-n
Don’t Care
DO a-n = data out from bank a, column n.
3 subsequent elements of data out appear in the programmed order following DO a-n.
Shown with nominal tAC, tDQSCK, and tDQSQ
.
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Consecutive Read Bursts: CAS Latencies (Burst Length = 4 or 8)
CAS Latency = 2
CK
CK
Read
NOP
Read
NOP
NOP
NOP
Command
Address
BAa, COL n
BAa, COL b
CL=2
DQS
DQ
DOa-n
DOa-b
CAS Latency = 2.5
CK
CK
Read
NOP
Read
NOP
NOP
NOP
Command
Address
BAa, COL n
BAa,COL b
CL=2.5
DQS
DQ
DOa- n
DOa- b
DO a-n (or a-b) = data out from bank a, column n (or bank a, column b).
When burst length = 4, the bursts are concatenated.
When burst length = 8, the second burst interrupts the first.
Don’t Care
3 subsequent elements of data out appear in the programmed order following DO a-n.
3 (or 7) subsequent elements of data out appear in the programmed order following DO a-b.
Shown with nominal tAC, tDQSCK, and tDQSQ
.
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Non-Consecutive Read Bursts: CAS Latencies (Burst Length = 4)
CAS Latency = 2
CK
CK
Read
NOP
NOP
Read
NOP
NOP
Command
Address
BAa, COL n
BAa, COL b
CL=2
DQS
DQ
DO a-n
DOa- b
CAS Latency = 2.5
CK
CK
Read
NOP
NOP
Read
NOP
NOP
NOP
Command
Address
BAa, COL n
BAa, COL b
CL=2.5
DQS
DQ
DO a-n
DOa- b
DO a-n (or a-b) = data out from bank a, column n (or bank a, column b).
3 subsequent elements of data out appear in the programmed order following DO a-n (and following DO a-b).
Shown with nominal tAC, tDQSCK, and tDQSQ
.
Don’t Care
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Random Read Accesses: CAS Latencies (Burst Length = 2, 4 or 8)
CAS Latency = 2
CK
CK
Read
Read
BAa, COL x
CL=2
Read
Read
NOP
NOP
Command
Address
BAa, COL n
BAa, COL b
BAa, COL g
DQS
DQ
DOa-n
DOa-n’
DOa-x
DOa-x’
DOa-b
DOa-b’
DOa-g
CAS Latency = 2.5
CK
CK
Read
Read
Read
Read
NOP
NOP
Command
Address
BAa, COL n
BAa, COL x
BAa, COL b
BAa, COL g
CL=2.5
DQS
DQ
DOa-n
DOa-n’
DOa-x
DOa-x’
DOa-b
DOa-b’
DO a-n, etc. = data out from bank a, column n etc.
n’ etc. = odd or even complement of n, etc. (i.e., column address LSB inverted).
Don’t Care
Reads are to active rows in any banks.
Shown with nominal tAC, tDQSCK, and tDQSQ
.
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Data from any Read burst may be truncated with a Burst Terminate command, as shown on Terminating a
Read Burst: CAS Latencies (Burst Length = 8) on page 25. The Burst Terminate latency is equal to the read
(CAS) latency, i.e. the Burst Terminate command should be issued x cycles after the Read command, where
x equals the number of desired data element pairs.
Data from any Read burst must be completed or truncated before a subsequent Write command can be
issued. If truncation is necessary, the Burst Terminate command must be used, as shown on Read to Write:
CAS Latencies (Burst Length = 4 or 8) on page 26. The example is shown for t
(min). The t
(max)
DQSS
DQSS
case, not shown here, has a longer bus idle time. t
Writes.
(min) and t
(max) are defined in the section on
DQSS
DQSS
A Read burst may be followed by, or truncated with, a Precharge command to the same bank (provided that
Auto Precharge was not activated). The Precharge command should be issued x cycles after the Read com-
mand, where x equals the number of desired data element pairs (pairs are required by the 2n prefetch archi-
tecture). This is shown on Read to Precharge: CAS Latencies (Burst Length = 4 or 8) on page 27 for Read
latencies of 2 and 2.5. Following the Precharge command, a subsequent command to the same bank cannot
be issued until t is met. Note that part of the row precharge time is hidden during the access of the last data
RP
elements.
In the case of a Read being executed to completion, a Precharge command issued at the optimum time (as
described above) provides the same operation that would result from the same Read burst with Auto Pre-
charge enabled. The disadvantage of the Precharge command is that it requires that the command and
address busses be available at the appropriate time to issue the command. The advantage of the Precharge
command is that it can be used to truncate bursts.
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Terminating a Read Burst: CAS Latencies (Burst Length = 8)
CAS Latency = 2
CK
CK
Read
NOP
BST
NOP
NOP
NOP
Command
Address
BAa, COL n
CL=2
DQS
DQ
DOa-n
No further output data after this point.
DQS tristated.
CAS Latency = 2.5
CK
CK
Read
NOP
BST
NOP
NOP
NOP
Command
Address
BAa, COL n
CL=2.5
DQS
DQ
DOa-n
No further output data after this point.
DQS tristated.
DO a-n = data out from bank a, column n.
Cases shown are bursts of 8 terminated after 4 data elements.
3 subsequent elements of data out appear in the programmed order following DO a-n.
Shown with nominal tAC, tDQSCK, and tDQSQ
Don’t Care
.
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256-Mbit Double Data Rate SDRAM
Read to Write: CAS Latencies (Burst Length = 4 or 8)
CAS Latency = 2
CK
CK
Read
BST
NOP
Write
NOP
NOP
Command
Address
BAa, COL n
BAa, COL b
CL=2
tDQSS (min)
DQS
DQ
DI a-b
DOa-n
DM
CAS Latency = 2.5
CK
CK
Read
BST
NOP
NOP
Write
NOP
Command
Address
BAa, COL n
BAa, COL b
CL=2.5
tDQSS (min)
DQS
DQ
DOa-n
Dla-b
DM
DO a-n = data out from bank a, column n
.
DI a-b = data in to bank a, column b
1 subsequent elements of data out appear in the programmed order following DO a-n.
Data In elements are applied following Dl a-b in the programmed order, according to burst length.
Shown with nominal tAC, tDQSCK, and tDQSQ
.
Don’t Care
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Read to Precharge: CAS Latencies (Burst Length = 4 or 8)
CAS Latency = 2
CK
CK
Read
NOP
PRE
NOP
NOP
ACT
Command
tRP
BA a or all
BA a, COL n
BA a, ROW
Address
CL=2
DQS
DQ
DOa-n
CAS Latency = 2.5
CK
CK
Read
NOP
PRE
NOP
NOP
ACT
Command
tRP
BA a or all
BA a, COL n
BA a, ROW
Address
CL=2.5
DQS
DQ
DOa-n
DO a-n = data out from bank a, column n.
Cases shown are either uninterrupted bursts of 4 or interrupted bursts of 8.
3 subsequent elements of data out appear in the programmed order following DO a-n.
Shown with nominal tAC, tDQSCK, and tDQSQ
.
Don’t Care
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Writes
Write bursts are initiated with a Write command, as shown on Write Command on page 29.
The starting column and bank addresses are provided with the Write command, and Auto Precharge is either
enabled or disabled for that access. If Auto Precharge is enabled, the row being accessed is precharged at
the completion of the burst. For the generic Write commands used in the following illustrations, Auto Pre-
charge is disabled.
During Write bursts, the first valid data-in element is registered on the first rising edge of DQS following the
write command, and subsequent data elements are registered on successive edges of DQS. The Low state
on DQS between the Write command and the first rising edge is known as the write preamble; the Low state
on DQS following the last data-in element is known as the write postamble. The time between the Write com-
mand and the first corresponding rising edge of DQS (t
) is specified with a relatively wide range (from
DQSS
75% to 125% of one clock cycle), so most of the Write diagrams that follow are drawn for the two extreme
cases (i.e. t (min) and t (max)). Write Burst (Burst Length = 4) on page 30 shows the two extremes of
DQSS
DQSS
t
for a burst of four. Upon completion of a burst, assuming no other commands have been initiated, the
DQSS
DQs and DQS enters High-Z and any additional input data is ignored.
Data for any Write burst may be concatenated with or truncated with a subsequent Write command. In either
case, a continuous flow of input data can be maintained. The new Write command can be issued on any pos-
itive edge of clock following the previous Write command. The first data element from the new burst is applied
after either the last element of a completed burst or the last desired data element of a longer burst which is
being truncated. The new Write command should be issued x cycles after the first Write command, where x
equals the number of desired data element pairs (pairs are required by the 2n prefetch architecture). Write to
Write (Burst Length = 4) on page 31 shows concatenated bursts of 4. An example of non-consecutive Writes
is shown on Write to Write: Max DQSS, Non-Consecutive (Burst Length = 4) on page 32. Full-speed random
write accesses within a page or pages can be performed as shown on Random Write Cycles (Burst Length =
2, 4 or 8) on page 33. Data for any Write burst may be followed by a subsequent Read command. To follow a
Write without truncating the write burst, t
(Write to Read) should be met as shown on Write to Read: Non-
WTR
Interrupting (CAS Latency = 2; Burst Length = 4) on page 34.
Data for any Write burst may be truncated by a subsequent Read command, as shown in the figures on Write
to Read: Interrupting (CAS Latency = 2; Burst Length = 8) on page 35 to Write to Read: Nominal DQSS, Inter-
rupting (CAS Latency = 2; Burst Length = 8) on page 37. Note that only the data-in pairs that are registered
prior to the t
period are written to the internal array, and any subsequent data-in must be masked with
WTR
DM, as shown in the diagrams noted previously.
Data for any Write burst may be followed by a subsequent Precharge command. To follow a Write without
truncating the write burst, t
should be met as shown on Write to Precharge: Non-Interrupting (Burst Length
WR
= 4) on page 38.
Data for any Write burst may be truncated by a subsequent Precharge command, as shown in the figures on
Write to Precharge: Interrupting (Burst Length = 4 or 8) on page 39 to Write to Precharge: Nominal DQSS (2
bit Write), Interrupting (Burst Length = 4 or 8) on page 41. Note that only the data-in pairs that are registered
prior to the t
period are written to the internal array, and any subsequent data in should be masked with
WR
DM. Following the Precharge command, a subsequent command to the same bank cannot be issued until t
is met.
RP
In the case of a Write burst being executed to completion, a Precharge command issued at the optimum time
(as described above) provides the same operation that would result from the same burst with Auto Pre-
charge. The disadvantage of the Precharge command is that it requires that the command and address bus-
ses be available at the appropriate time to issue the command. The advantage of the Precharge command is
that it can be used to truncate bursts.
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Write Command
CK
CK
HIGH
CKE
CS
RAS
CAS
WE
x4: A0-A9, A11
x8: A0-A9
CA
x16: A0-A8
EN AP
A10
DIS AP
BA
CA = column address
BA = bank address
EN AP = enable Auto Precharge
DIS AP = disable Auto Precharge
BA0, BA1
Don’t Care
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Write Burst (Burst Length = 4)
Maximum DQSS
T1
T2
T3
T4
CK
CK
Write
NOP
NOP
NOP
Command
BA a, COL b
Address
tDQSS (max)
DQS
DQ
Dla-b
DM
Minimum DQSS
T4
T1
T2
T3
CK
CK
Write
NOP
NOP
NOP
Command
BA a, COL b
Address
tDQSS (min)
DQS
DQ
Dla-b
DM
DI a-b = data in for bank a, column b.
3 subsequent elements of data in are applied in the programmed order following DI a-b.
A non-interrupted burst is shown.
A10 is Low with the Write command (Auto Precharge is disabled).
Don’t Care
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Write to Write (Burst Length = 4)
Maximum DQSS
T1
T2
T3
T4
T5
T6
CK
CK
Write
NOP
Write
NOP
NOP
NOP
Command
Address
BAa, COL b
BAa, COL n
tDQSS (max)
DQS
DQ
DI a-b
DI a-n
DM
Minimum DQSS
T1
T2
T3
T4
T5
T6
CK
CK
Write
NOP
Write
NOP
NOP
NOP
Command
Address
BA, COL b
BA, COL n
tDQSS (min)
DQS
DQ
DI a-b
DI a-n
DM
DI a-b = data in for bank a, column b, etc.
3 subsequent elements of data in are applied in the programmed order following DI a-b.
3 subsequent elements of data in are applied in the programmed order following DI a-n.
A non-interrupted burst is shown.
Don’t Care
Each Write command may be to any bank.
10/01
Page 31 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Write to Write: Max DQSS, Non-Consecutive (Burst Length = 4)
T1
T2
T3
T4
T5
CK
CK
Write
NOP
NOP
Write
NOP
Command
Address
BAa, COL b
BAa, COL n
tDQSS (max)
DQS
DQ
DI a-b
DI a-n
DM
DI a-b, etc. = data in for bank a, column b, etc.
3 subsequent elements of data in are applied in the programmed order following DI a-b.
3 subsequent elements of data in are applied in the programmed order following DI a-n.
A non-interrupted burst is shown.
Don’t Care
Each Write command may be to any bank.
10/01
Page 32 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Random Write Cycles (Burst Length = 2, 4 or 8)
Maximum DQSS
T1
T2
T3
T4
T5
CK
CK
Write
Write
Write
Write
Write
Command
Address
BAa, COL b
BAa, COL x
BAa, COL n
BAa, COL a
BAa, COL g
tDQSS (max)
DQS
DQ
DI a-b
DI a-b’
DI a-x
DI a-x’
DI a-n
DI a-n’
DI a-a
DI a-a’
DM
Minimum DQSS
T5
T1
T2
T3
T4
CK
CK
Write
Write
Write
Write
Write
Command
Address
BAa, COL b
BAa, COL x
BAa, COL n
BAa, COL a
BAa, COL g
tDQSS (min)
DQS
DQ
DI a-g
DI a-b
DI a-b’
DI a-x
DI a-x’
DI a-n
DI a-n’
DI a-a
DI a-a’
DM
DI a-b, etc. = data in for bank a, column b, etc.
b’, etc. = odd or even complement of b, etc. (i.e., column address LSB inverted).
Each Write command may be to any bank.
Don’t Care
10/01
Page 33 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Write to Read: Non-Interrupting (CAS Latency = 2; Burst Length = 4)
Maximum DQSS
T5 T6
T1
T2
T3
T4
CK
CK
Write
NOP
NOP
NOP
Read
NOP
Command
tWTR
BAa, COL b
BAa, COL n
Address
CL = 2
tDQSS (max)
DQS
DQ
DI a-b
DM
Minimum DQSS
T5 T6
T1
T2
T3
T4
CK
CK
Write
NOP
NOP
NOP
Read
NOP
Command
tWTR
BAa, COL n
BAa, COL b
Address
CL = 2
tDQSS (min)
DQS
DQ
DI a-b
DM
DI a-b = data in for bank a, column b.
3 subsequent elements of data in are applied in the programmed order following DI a-b.
A non-interrupted burst is shown.
tWTR is referenced from the first positive CK edge after the last data in pair.
A10 is Low with the Write command (Auto Precharge is disabled).
The Read and Write commands may be to any bank.
Don’t Care
10/01
Page 34 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Write to Read: Interrupting (CAS Latency = 2; Burst Length = 8)
Maximum DQSS
T5 T6
T1
T2
T3
T4
CK
CK
Write
NOP
NOP
NOP
Read
NOP
Command
tWTR
BAa, COL n
BAa, COL b
Address
CL = 2
tDQSS (max)
DQS
DQ
DIa- b
1
1
DM
Minimum DQSS
T5 T6
T1
T2
T3
T4
CK
CK
Write
NOP
NOP
NOP
Read
NOP
Command
tWTR
BAa, COL n
BAa, COL b
Address
CL = 2
tDQSS (min)
DQS
DQ
DI a-b
1
1
DM
DI a-b = data in for bank a, column b.
An interrupted burst is shown, 4 data elements are written.
3 subsequent elements of data in are applied in the programmed order following DI a-b.
tWTR is referenced from the first positive CK edge after the last data in pair.
The Read command masks the last 2 data elements in the burst.
A10 is Low with the Write command (Auto Precharge is disabled).
The Read and Write commands are not necessarily to the same bank.
1 = These bits are incorrectly written into the memory array if DM is low.
Don’t Care
10/01
Page 35 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Write to Read: Minimum DQSS, Odd Number of Data (3 bit Write), Interrupting (CAS
Latency = 2; Burst Length = 8)
T1
T2
T3
T4
T5
T6
CK
CK
Write
NOP
NOP
NOP
Read
NOP
Command
tWTR
BAa, COL n
BAa, COL b
Address
CL = 2
tDQSS (min)
DQS
DQ
DI a-b
1
2
2
DM
DI a-b = data in for bank a, column b.
An interrupted burst is shown, 3 data elements are written.
2 subsequent elements of data in are applied in the programmed order following DI a-b.
WTR is referenced from the first positive CK edge after the last desired data in pair (not the last desired data in element)
t
The Read command masks the last 2 data elements in the burst.
A10 is Low with the Write command (Auto Precharge is disabled).
The Read and Write commands are not necessarily to the same bank.
1 = This bit is correctly written into the memory array if DM is low.
2 = These bits are incorrectly written into the memory array if DM is low.
Don’t Care
10/01
Page 36 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Write to Read: Nominal DQSS, Interrupting (CAS Latency = 2; Burst Length = 8)
T1
T2
T3
T4
T5
T6
CK
CK
Write
NOP
NOP
NOP
Read
NOP
Command
tWTR
BAa, COL n
BAa, COL b
Address
CL = 2
tDQSS (nom)
DQS
DQ
DI a-b
DM
1
1
DI a-b = data in for bank a, column b.
An interrupted burst is shown, 4 data elements are written.
3 subsequent elements of data in are applied in the programmed order following DI a-b.
tWTR is referenced from the first positive CK edge after the last desired data in pair.
The Read command masks the last 2 data elements in the burst.
A10 is Low with the Write command (Auto Precharge is disabled).
The Read and Write commands are not necessarily to the same bank.
1 = These bits are incorrectly written into the memory array if DM is low.
Don’t Care
10/01
Page 37 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Write to Precharge: Non-Interrupting (Burst Length = 4)
Maximum DQSS
T5 T6
T1
T2
T3
T4
CK
CK
Write
NOP
NOP
NOP
NOP
tWR
PRE
Command
BA (a or all)
BA a, COL b
Address
tRP
tDQSS (max)
DQS
DQ
DI a-b
DM
Minimum DQSS
T1
T2
T3
T4
T5
T6
CK
CK
Write
NOP
NOP
NOP
NOP
tWR
PRE
Command
BA (a or all)
BA a, COL b
Address
tRP
tDQSS (min)
DQS
DQ
DI a-b
DM
DI a-b = data in for bank a, column b.
3 subsequent elements of data in are applied in the programmed order following DI a-b.
A non-interrupted burst is shown.
t
WR is referenced from the first positive CK edge after the last data in pair.
Don’t Care
A10 is Low with the Write command (Auto Precharge is disabled).
10/01
Page 38 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Write to Precharge: Interrupting (Burst Length = 4 or 8)
Maximum DQSS
T5 T6
T1
T2
T3
T4
CK
CK
Write
NOP
NOP
NOP
tWR
PRE
NOP
Command
BA (a or all)
BA a, COL b
Address
tRP
tDQSS (max)
2
DQS
DQ
DI a-b
1
1
3
3
DM
Minimum DQSS
T5 T6
T1
T2
T3
T4
CK
CK
Write
NOP
NOP
NOP
tWR
PRE
NOP
Command
BA a, COL b
BA (a or all)
Address
tRP
tDQSS (min)
2
DQS
DQ
DI a-b
3
3
1
1
DM
DI a-b = data in for bank a, column b.
An interrupted burst is shown, 2 data elements are written.
1 subsequent element of data in is applied in the programmed order following DI a-b.
tWR is referenced from the first positive CK edge after the last desired data in pair.
The Precharge command masks the last 2 data elements in the burst, for burst length = 8.
A10 is Low with the Write command (Auto Precharge is disabled).
1 = Can be don’t care for programmed burst length of 4.
2 = For programmed burst length of 4, DQS becomes don’t care at this point.
3 = These bits are incorrectly written into the memory array if DM is low.
Don’t Care
10/01
Page 39 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Write to Precharge: Minimum DQSS, Odd Number of Data (1 bit Write), Interrupting
(Burst Length = 4 or 8)
T1
T2
T3
T4
T5
T6
CK
CK
Write
NOP
NOP
NOP
tWR
PRE
NOP
Command
BA a, COL b
BA (a or all)
Address
tRP
tDQSS (min)
2
DQS
DQ
DI a-b
1
1
3
4
4
DM
DI a-b = data in for bank a, column b.
An interrupted burst is shown, 1 data element is written.
tWR is referenced from the first positive CK edge after the last desired data in pair.
The Precharge command masks the last 2 data elements in the burst.
A10 is Low with the Write command (Auto Precharge is disabled).
1 = Can be don’t care for programmed burst length of 4.
2 = For programmed burst length of 4, DQS becomes don’t care at this point.
3 = This bit is correctly written into the memory array if DM is low.
4 = These bits are incorrectly written into the memory array if DM is low.
Don’t Care
10/01
Page 40 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Write to Precharge: Nominal DQSS (2 bit Write), Interrupting (Burst Length = 4 or 8)
T1
T2
T3
T4
T5
T6
CK
CK
Write
NOP
NOP
NOP
tWR
PRE
NOP
Command
BA (a or all)
BA a, COL b
Address
tRP
tDQSS (nom)
2
DQS
DQ
DI a-b
3
3
1
1
DM
DI a-b = Data In for bank a, column b.
An interrupted burst is shown, 2 data elements are written.
1 subsequent element of data in is applied in the programmed order following DI a-b.
tWR is referenced from the first positive CK edge after the last desired data in pair.
The Precharge command masks the last 2 data elements in the burst.
A10 is Low with the Write command (Auto Precharge is disabled).
1 = Can be don’t care for programmed burst length of 4.
2 = For programmed burst length of 4, DQS becomes don’t care at this point.
Don’t Care
3 = These bits are incorrectly written into the memory array if DM is low.
10/01
Page 41 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Precharge Command
CK
CK
HIGH
CKE
CS
RAS
CAS
WE
A0-A9, A11, A12
All Banks
A10
One Bank
BA
BA0, BA1
BA = bank address
(if A10 is Low, otherwise Don’t Care).
Don’t Care
Precharge
The Precharge command is used to deactivate the open row in a particular bank or the open row in all banks.
The bank(s) will be available for a subsequent row access some specified time (t ) after the Precharge com-
RP
mand is issued. Input A10 determines whether one or all banks are to be precharged, and in the case where
only one bank is to be precharged, inputs BA0, BA1 select the bank. When all banks are to be precharged,
inputs BA0, BA1 are treated as “Don’t Care.” Once a bank has been precharged, it is in the idle state and
must be activated prior to any Read or Write commands being issued to that bank.
10/01
Page 42 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Power-Down
Power-down is entered when CKE is registered LOW (no accesses can be in progress). If power-down
occurs when all banks are idle, this mode is referred to as precharge power-down; if power-down occurs
when there is a row active in any bank, this mode is referred to as active power-down. Entering power-down
deactivates the input and output buffers, excluding CK, CK and CKE. The DLL is still running in Power Down
mode, so for maximum power savings, the user has the option of disabling the DLL prior to entering Power-
down. In that case, the DLL must be enabled after exiting power-down, and 200 clock cycles must occur
before a Read command can be issued. In power-down mode, CKE Low and a stable clock signal must be
maintained at the inputs of the DDR SDRAM, and all other input signals are “Don’t Care”. However, power-
down duration is limited by the refresh requirements of the device, so in most applications, the self refresh
mode is preferred over the DLL-disabled power-down mode.
The power-down state is synchronously exited when CKE is registered HIGH (along with a Nop or Deselect
command). A valid, executable command may be applied one clock cycle later.
Power Down
CK
CK
tIS
tIS
CKE
Command
VALID
NOP
VALID
NOP
No column
access in
progress
Exit
power down
mode
Don’t Care
Enter Power Down mode
(Burst Read or Write operation
must not be in progress)
10/01
Page 43 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Truth Table 2: Clock Enable (CKE)
1. CKEn is the logic state of CKE at clock edge n: CKE n-1 was the state of CKE at the previous clock edge.
2. Current state is the state of the DDR SDRAM immediately prior to clock edge n.
3. COMMAND n is the command registered at clock edge n, and ACTION n is a result of COMMAND n.
4. All states and sequences not shown are illegal or reserved.
CKE n-1
CKEn
Current State
Command n
Action n
Notes
Previous Current
Cycle
Cycle
Self Refresh
Self Refresh
Power Down
Power Down
All Banks Idle
All Banks Idle
Bank(s) Active
L
L
L
H
L
X
Maintain Self-Refresh
Deselect or NOP
X
Exit Self-Refresh
1
L
Maintain Power-Down
Exit Power-Down
L
H
L
Deselect or NOP
Deselect or NOP
AUTO REFRESH
Deselect or NOP
H
H
H
Precharge Power-Down Entry
Self Refresh Entry
L
L
Active Power-Down Entry
See “Truth Table 3: Current State
Bank n - Command to Bank n
(Same Bank)” on page 45
H
H
1. Deselect or NOP commands should be issued on any clock edges occurring during the Self Refresh Exit (tXSNR) period. A mini-
mum of 200 clock cycles are needed before applying a read command to allow the DLL to lock to the input clock.
10/01
Page 44 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Truth Table 3: Current State Bank n - Command to Bank n (Same Bank) (Part 1 of 2)
Current State
Any
CS
H
RAS CAS
WE
X
Command
Deselect
Action
Notes
1-6
X
H
L
X
H
H
L
NOP. Continue previous operation
NOP. Continue previous operation
L
H
No Operation
1-6
L
L
L
L
L
L
L
L
L
H
H
L
Active
AUTO REFRESH
MODE REGISTER SET
Read
Select and activate row
1-6
1-7
Idle
L
L
H
H
L
L
L
1-7
H
L
Select column and start Read burst
Select column and start Write burst
Deactivate row in bank(s)
1-6, 10
1-6, 10
1-6, 8
1-6, 10
1-6, 8
1-6, 9
Row Active
L
Write
H
L
L
Precharge
H
L
H
L
Read
Select column and start new Read burst
Truncate Read burst, start Precharge
BURST TERMINATE
Read
(Auto Precharge
Disabled)
H
H
Precharge
H
L
BURST TERMINATE
1. This table applies when CKE n-1 was HIGH and CKE n is HIGH (see Truth Table 2: Clock Enable (CKE) and after tXSNR / tXSRD
has been met (if the previous state was self refresh).
2. This table is bank-specific, except where noted, i.e., the current state is for a specific bank and the commands shown are those
allowed to be issued to that bank when in that state. Exceptions are covered in the notes below.
3. Current state definitions:
Idle:
The bank has been precharged, and tRP has been met.
Row Active:
A row in the bank has been activated, and tRCD has been met. No data bursts/accesses and no register
accesses are in progress.
Read:
Write:
A Read burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
A Write burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
4. The following states must not be interrupted by a command issued to the same bank.
Precharging:
Starts with registration of a Precharge command and ends when tRP is met. Once tRP is met, the bank is in the
idle state.
Row Activating: Starts with registration of an Active command and ends when tRCD is met. Once tRCD is met, the bank is in the
“row active” state.
Read w/Auto Precharge Enabled: Starts with registration of a Read command with Auto Precharge enabled and ends when tRP
has been met. Once tRP is met, the bank is in the idle state.
Write w/Auto Precharge Enabled: Starts with registration of a Write command with Auto Precharge enabled and ends when tRP
has been met. Once tRP is met, the bank is in the idle state.
Deselect or NOP commands, or allowable commands to the other bank should be issued on any clock edge occurring during these
states. Allowable commands to the other bank are determined by its current state and according to Truth Table 4.
5. The following states must not be interrupted by any executable command; Deselect or NOP commands must be applied on each
positive clock edge during these states.
Refreshing:
Starts with registration of an Auto Refresh command and ends when tRFC is met. Once tRFC is met, the DDR
SDRAM is in the “all banks idle” state.
Accessing Mode Register: Starts with registration of a Mode Register Set command and ends when tMRD has been met. Once
tMRD is met, the DDR SDRAM is in the “all banks idle” state.
Precharging All: Starts with registration of a Precharge All command and ends when tRP is met. Once tRP is met, all banks is in
the idle state.
6. All states and sequences not shown are illegal or reserved.
7. Not bank-specific; requires that all banks are idle.
8. May or may not be bank-specific; if all/any banks are to be precharged, all/any must be in a valid state for precharging.
9. Not bank-specific; BURST TERMINATE affects the most recent Read burst, regardless of bank.
10. Reads or Writes listed in the Command/Action column include Reads or Writes with Auto Precharge enabled and Reads or Writes
with Auto Precharge disabled.
11. Requires appropriate DM masking.
10/01
Page 45 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Truth Table 3: Current State Bank n - Command to Bank n (Same Bank) (Part 2 of 2)
Current State
CS
L
RAS CAS
WE
H
Command
Read
Action
Notes
1-6, 10, 11
1-6, 10
H
H
L
L
L
Select column and start Read burst
Write
(Auto Precharge
Disabled)
L
L
L
L
Write
Select column and start Write burst
Truncate Write burst, start Precharge
H
Precharge
1-6, 8, 11
1. This table applies when CKE n-1 was HIGH and CKE n is HIGH (see Truth Table 2: Clock Enable (CKE) and after tXSNR / tXSRD
has been met (if the previous state was self refresh).
2. This table is bank-specific, except where noted, i.e., the current state is for a specific bank and the commands shown are those
allowed to be issued to that bank when in that state. Exceptions are covered in the notes below.
3. Current state definitions:
Idle:
The bank has been precharged, and tRP has been met.
Row Active:
A row in the bank has been activated, and tRCD has been met. No data bursts/accesses and no register
accesses are in progress.
Read:
Write:
A Read burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
A Write burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
4. The following states must not be interrupted by a command issued to the same bank.
Precharging:
Starts with registration of a Precharge command and ends when tRP is met. Once tRP is met, the bank is in the
idle state.
Row Activating: Starts with registration of an Active command and ends when tRCD is met. Once tRCD is met, the bank is in the
“row active” state.
Read w/Auto Precharge Enabled: Starts with registration of a Read command with Auto Precharge enabled and ends when tRP
has been met. Once tRP is met, the bank is in the idle state.
Write w/Auto Precharge Enabled: Starts with registration of a Write command with Auto Precharge enabled and ends when tRP
has been met. Once tRP is met, the bank is in the idle state.
Deselect or NOP commands, or allowable commands to the other bank should be issued on any clock edge occurring during these
states. Allowable commands to the other bank are determined by its current state and according to Truth Table 4.
5. The following states must not be interrupted by any executable command; Deselect or NOP commands must be applied on each
positive clock edge during these states.
Refreshing:
Starts with registration of an Auto Refresh command and ends when tRFC is met. Once tRFC is met, the DDR
SDRAM is in the “all banks idle” state.
Accessing Mode Register: Starts with registration of a Mode Register Set command and ends when tMRD has been met. Once
tMRD is met, the DDR SDRAM is in the “all banks idle” state.
Precharging All: Starts with registration of a Precharge All command and ends when tRP is met. Once tRP is met, all banks is in
the idle state.
6. All states and sequences not shown are illegal or reserved.
7. Not bank-specific; requires that all banks are idle.
8. May or may not be bank-specific; if all/any banks are to be precharged, all/any must be in a valid state for precharging.
9. Not bank-specific; BURST TERMINATE affects the most recent Read burst, regardless of bank.
10. Reads or Writes listed in the Command/Action column include Reads or Writes with Auto Precharge enabled and Reads or Writes
with Auto Precharge disabled.
11. Requires appropriate DM masking.
10/01
Page 46 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Truth Table 4: Current State Bank n - Command to Bank m (Different bank)
(Part 1 of 2)
Current State
Any
CS
H
RAS CAS
WE
X
Command
Deselect
Action
Notes
1-6
X
H
X
H
NOP/continue previous operation
NOP/continue previous operation
L
H
No Operation
1-6
Any Command Otherwise
Allowed to Bank m
Idle
X
X
X
X
1-6
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
H
H
L
H
L
H
H
L
Active
Read
Select and activate row
1-6
1-7
Row Activating,
Active, or
Precharging
Select column and start Read burst
Select column and start Write burst
L
Write
1-7
H
H
L
L
Precharge
Active
1-6
L
H
H
L
Select and activate row
1-6
Read
(Auto Precharge
H
L
Read
Select column and start new Read burst
1-7
Disabled)
H
H
L
Precharge
Active
1-6
L
H
H
L
Select and activate row
1-6
Write
(Auto Precharge
Disabled)
H
H
L
Read
Select column and start Read burst
Select column and start new Write burst
1-8
L
Write
1-7
H
H
L
L
Precharge
Active
1-6
L
H
H
L
Select and activate row
1-6
H
H
L
Read
Select column and start new Read burst
Select column and start Write burst
1-7,10
1-7,9,10
1-6
Read (With
Auto Precharge)
L
Write
H
L
Precharge
1. This table applies when CKE n-1 was HIGH and CKE n is HIGH (see Truth Table 2: Clock Enable (CKE) and after tXSNR / tXSRD
has been met (if the previous state was self refresh).
2. This table describes alternate bank operation, except where noted, i.e., the current state is for bank n and the commands shown
are those allowed to be issued to bank m (assuming that bank m is in such a state that the given command is allowable). Excep-
tions are covered in the notes below.
3. Current state definitions:
Idle:
Row Active:
The bank has been precharged, and tRP has been met.
A row in the bank has been activated, and tRCD has been met. No data bursts/accesses and no register
accesses are in progress.
Read:
Write:
A Read burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
A Write burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
Read with Auto Precharge Enabled: See note 10.
Write with Auto Precharge Enabled: See note 10.
4. AUTO REFRESH and Mode Register Set commands may only be issued when all banks are idle.
5. A BURST TERMINATE command cannot be issued to another bank; it applies to the bank represented by the current state only.
6. All states and sequences not shown are illegal or reserved.
7. Reads or Writes listed in the Command/Action column include Reads or Writes with Auto Precharge enabled and Reads or Writes
with Auto Precharge disabled.
8. Requires appropriate DM masking.
9. A Write command may be applied after the completion of data output.
10. Concurrent Auto Precharge:
This device supports “Concurrent Auto Precharge”. When a read with auto precharge or a write with auto precharge is enabled any
command may follow to the other banks as long as that command does not interrupt the read or write data transfer and all other
limitations apply (e.g. contention between READ data and WRITE data must be avoided). The mimimum delay from a read or write
command with auto precharge enable, to a command to a different banks is summarized in table 4a.
10/01
Page 47 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Truth Table 4: Current State Bank n - Command to Bank m (Different bank)
(Part 2 of 2)
Current State
CS
L
RAS CAS
WE
H
Command
Active
Action
Notes
1-6
L
H
H
L
H
L
Select and activate row
L
H
Read
Select column and start Read burst
Select column and start new Write burst
1-7,10
1-7,10
1-6
Write (With
Auto Precharge)
L
L
L
Write
L
H
L
Precharge
1. This table applies when CKE n-1 was HIGH and CKE n is HIGH (see Truth Table 2: Clock Enable (CKE) and after tXSNR / tXSRD
has been met (if the previous state was self refresh).
2. This table describes alternate bank operation, except where noted, i.e., the current state is for bank n and the commands shown
are those allowed to be issued to bank m (assuming that bank m is in such a state that the given command is allowable). Excep-
tions are covered in the notes below.
3. Current state definitions:
Idle:
The bank has been precharged, and tRP has been met.
Row Active:
A row in the bank has been activated, and tRCD has been met. No data bursts/accesses and no register
accesses are in progress.
Read:
Write:
A Read burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
A Write burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
Read with Auto Precharge Enabled: See note 10.
Write with Auto Precharge Enabled: See note 10.
4. AUTO REFRESH and Mode Register Set commands may only be issued when all banks are idle.
5. A BURST TERMINATE command cannot be issued to another bank; it applies to the bank represented by the current state only.
6. All states and sequences not shown are illegal or reserved.
7. Reads or Writes listed in the Command/Action column include Reads or Writes with Auto Precharge enabled and Reads or Writes
with Auto Precharge disabled.
8. Requires appropriate DM masking.
9. A Write command may be applied after the completion of data output.
10. Concurrent Auto Precharge:
This device supports “Concurrent Auto Precharge”. When a read with auto precharge or a write with auto precharge is enabled any
command may follow to the other banks as long as that command does not interrupt the read or write data transfer and all other
limitations apply (e.g. contention between READ data and WRITE data must be avoided). The mimimum delay from a read or write
command with auto precharge enable, to a command to a different banks is summarized in table 4a.
Truth Table 4a : Concurrent Auto Precharge:
Minimum Delay with Con-
To Command
(different bank)
From Command
WRITE w/AP
current Auto Precharge
Support
Units
Read or Read w/AP
Write ot Write w/AP
Precharge or Activate
Read or Read w/AP
Write or Write w/AP
Precharge or Activate
1 + (BL/2) + tWTR
tCK
tCK
tCK
tCK
tCK
tCK
BL/2
1
BL/2
Read w/AP
CL (rounded up)+ BL/2
1
10/01
Page 48 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Simplified State Diagram
Power
Applied
Power
On
Self
Refresh
Precharge
PREALL
REFS
REFSX
MRS
EMRS
Auto
Refresh
MRS
REFA
Idle
CKEL
CKEH
Active
Power
Down
ACT
Precharge
Power
Down
CKEH
CKEL
Burst Stop
Row
Active
Read
Write
Write A
Read A
Write
Read
Read
Read A
Write A
Read
A
PRE
Write
A
Read
A
PRE
PRE
Precharge
PREALL
PRE
Automatic Sequence
Command Sequence
PREALL = Precharge All Banks
MRS = Mode Register Set
EMRS = Extended Mode Register Set
REFS = Enter Self Refresh
REFSX = Exit Self Refresh
REFA = Auto Refresh
CKEL = Enter Power Down
CKEH = Exit Power Down
ACT = Active
Write A = Write with Autoprecharge
Read A = Read with Autoprecharge
PRE = Precharge
10/01
Page 49 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Operating Conditions
Absolute Maximum Ratings
Symbol
Parameter
Rating
Units
V
VIN, VOUT Voltage on I/O pins relative to VSS
−0.5 to VDDQ+ 0.5
−0.5 to +3.6
VIN
Voltage on Inputs relative to VSS
V
VDD
Voltage on VDD supply relative to VSS
−0.5 to +3.6
V
VDDQ
TA
Voltage on VDDQ supply relative to VSS
Operating Temperature (Ambient)
Storage Temperature (Plastic)
Power Dissipation
−0.5 to +3.6
0 to +70
−55 to +150
1.0
V
°C
°C
W
TSTG
PD
IOUT
Short Circuit Output Current
50
mA
Note: Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a
stress rating only, and functional operation of the device at these or any other conditions above those indicated in the operational sec-
tions of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability.
Input and Output Capacitances
Parameter
Symbol
CI1
Min.
2.0
-
Max.
3.0
Units
pF
Notes
Input Capacitance: CK, CK
Delta Input Capacitance
1
1
CdI1
CI2
0.25
3.0
pF
Input Capacitance: All other input-only pins
Input/Output Capacitance: DQ, DQS, DM
Delta Input/Output Capacitance : DQ, DQS, DM
2.0
4.0
-
pF
1
CIO
5.0
pF
1, 2
1
CdIO
0.5
pF
1. These values are guaranteed by design and are tested on a sample base only. VDDQ = VDD = 2.5V ± 0.2V, f = 100MHz, TA = 25°C,
VOUT (DC) = VDDQ/2, VOUT (Peak to Peak) 0.2V. Unused pins are tied to groundVOUT (Peak to Peak) = 0.2V.
2. DM inputs are grouped with I/O pins reflecting the fact that they are matched in loading to DQ and DQS to facilitate trace matching
at the board level.
10/01
Page 50 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
DC Electrical Operating Conditions
(0°C ≤ T ≤ 70°C; V
= 2.5V ± 0.2V, V = + 2.5V ± 0.2V)
A
DDQ
DD
Symbol
Parameter
Min
Max
Units
V
Notes
VDD
Supply Voltage
2.3
2.7
1
1
VDDQ
I/O Supply Voltage
2.3
0
2.7
0
V
V
SS, VSSQ Supply Voltage, I/O Supply Voltage
V
VREF
VTT
I/O Reference Voltage
0.49 x VDDQ
0.51 x VDDQ
V
1, 2
1, 3
1
I/O Termination Voltage (System)
Input High (Logic1) Voltage
V
REF − 0.04
REF + 0.18
− 0.3
V
REF + 0.04
V
VIH(DC)
VIL(DC)
VIN(DC)
VID(DC)
VIRatio
V
V
DDQ + 0.3
V
Input Low (Logic0) Voltage
V
REF − 0.18
V
1
Input Voltage Level, CK and CK Inputs
Input Differential Voltage, CK and CK Inputs
VI-Matching Pullup Current to Pulldown Current
− 0.3
V
DDQ + 0.3
DDQ + 0.6
1.4
V
1
0.36
V
V
1, 4
5
0.71
Input Leakage Current Any input 0V ≤ VIN ≤ VDD
(All other pins not under test = 0V)
II
− 2
2
5
µA
1
IOZ
IOH
IOL
Output Leakage Current (DQs are disabled; 0V ≤ Vout ≤ VDDQ)
Output High Current, Normal Strength Driver (VOUT = 1.95 V)
Output Low Current, Normal Strength Driver (VOUT = 0.35 V))
− 5
− 15.2
15.2
µA
mA
mA
1
1
1
1. Inputs are not recognized as valid until VREF stabilizes.
2. VREF is expected to be equal to 0.5 VDDQ of the transmitting device, and to track variations in the DC level of the same. Peak-to-
peak noise on VREF may not exceed ± 2% of the DC value.
3. VTT is not applied directly to the device. VTT is a system supply for signal termination resistors, is expected to be set equal to VREF
,
and must track variations in the DC level of VREF
.
4. VID is the magnitude of the difference between the input level on CK and the input level on CK.
5. The ration of the pullup current to the pulldown current is specified for the same temperature and voltage, over the entire tempera-
ture and voltage range, for device drain to source voltage from 0.25 to 1.0V. For a given output, it represents the maximum differ-
ence between pullup and pulldown drivers due to process variation.
10/01
Page 51 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Pulldown and Pullup Characteristics
1. The nominal pulldown V-I curve for DDR SDRAM devices is expected, but not guaranteed, to lie within the
inner bounding lines of the V-I curve.
2. The full variation in driver pulldown current from minimum to maximum process, temperature, and voltage
lie within the outer bounding lines of the V-I curve.
Pulldown Characteristics
140
Maximum
120
100
Nominal High
80
60
40
Nominal Low
Minimum
20
0
0
0.5
1
1.5
2
2.5
V
(V)
OUT
3. The nominal pullup V-I curve for DDR SDRAM devices is expected, but not guaranteed, to lie within the
inner bounding lines of the V-I curve.
4. The full variation in driver pullup current from minimum to maximum process, temperature, and voltage lie
within the outer bounding lines of the V-I curve.
Pullup Characteristics
0
-20
Minimum
Nominal Low
-40
-60
-80
-100
-120
-140
-160
Nominal High
Maximum
0
0.5
1
1.5
(V)
2
2.5
V
OUT
5. The full variation in the ratio of the maximum to minimum pullup and pulldown current does not exceed
1.7, for device drain to source voltages from 0.1 to 1.0.
6. The full variation in the ratio of the nominal pullup to pulldown current should be unity ± 10%, for device
drain to source voltages from 0.1 to 1.0V.
10/01
Page 52 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Pulldown and Pullup Currents
Pulldown Current (mA)
Pullup Current (mA)
Nominal
Low
Nominal
High
Nominal
Low
Nominal
High
Voltage (V)
Min
Max
Min
Max
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
6.0
6.8
4.6
9.6
−6.1
−7.6
−14.5
−21.2
−27.7
−34.1
−40.5
−46.9
−53.1
−59.4
−65.5
−71.6
−77.6
−83.6
−89.7
−95.5
−101.3
−107.1
−112.4
−118.7
−124.0
−129.3
−134.6
−139.9
−145.2
−150.5
-155.3
-160.1
−4.6
−10.0
−20.0
12.2
18.1
24.1
29.8
34.6
39.4
43.7
47.5
51.3
54.1
56.2
57.9
59.3
60.1
60.5
61.0
61.5
62.0
62.5
62.9
63.3
63.8
64.1
64.6
64.8
65.0
13.5
20.1
26.6
33.0
39.1
44.2
49.8
55.2
60.3
65.2
69.9
74.2
78.4
82.3
85.9
89.1
92.2
95.3
97.2
99.1
100.9
101.9
102.8
103.8
104.6
105.4
9.2
18.2
−12.2
−18.1
−24.0
−29.8
−34.3
−38.1
−41.1
−43.8
−46.0
−47.8
−49.2
−50.0
−50.5
−50.7
−51.0
−51.1
−51.3
−51.5
−51.6
−51.8
−52.0
−52.2
−52.3
−52.5
-52.7
-52.8
−9.2
13.8
18.4
23.0
27.7
32.2
36.8
39.6
42.6
44.8
46.2
47.1
47.4
47.7
48.0
48.4
48.9
49.1
49.4
49.6
49.8
49.9
50.0
50.2
50.4
50.5
26.0
−13.8
−18.4
−23.0
−27.7
−32.2
−36.0
−38.2
−38.7
−39.0
−39.2
−39.4
−39.6
−39.9
−40.1
−40.2
−40.3
−40.4
−40.5
−40.6
−40.7
−40.8
−40.9
−41.0
-41.1
-41.2
−29.8
33.9
−38.8
41.8
−46.8
49.4
−54.4
56.8
−61.8
63.2
−69.5
69.9
−77.3
76.3
−85.2
82.5
−93.0
88.3
−100.6
−108.1
−115.5
−123.0
−130.4
−136.7
−144.2
−150.5
−156.9
−163.2
−169.6
−176.0
−181.3
−187.6
-192.9
-198.2
93.8
99.1
103.8
108.4
112.1
115.9
119.6
123.3
126.5
129.5
132.4
135.0
137.3
139.2
140.8
Pulldown and Pullup Process Variations and Conditions
Nominal
Minimum
Maximum
25 °C
0 °C
70 °C
Operating Temperature
VDD / VDDQ
2.5V
2.3V
2.7V
The above characteristics are specified under best, worst, and nominal process variations / conditions.
10/01
Page 53 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
IDD Specification and Conditions
(0 °C ≤ T ≤ 70 °C; V
= 2.5V ± 0.2V; V = 2.5V ± 0.2)
A
DDQ
DD
DDR200
DDR266A
typ. max
Notes
4)
Symbol
Parameter/Condition
Unit
mA
typ.
max
Operating Current: one bank; active / precharge; tRC = tRC MIN
CK = tCK MIN; DQ, DM, and DQS inputs changing once per clock
cycle; address and control inputs changing once every two clock
cycles
;
t
IDD0
1, 2
71
90
76
100
Operating Current: one bank; active / read / precharge; Burst =
4; Refer to the following page for detailed test conditions.
IDD1
88
100
15
97
120
20
mA
mA
1, 2
1, 2
Precharge Power-Down Standby Current: all banks idle;
power-down mode; CKE ≤ VIL MAX; tCK = tCK MIN
IDD2P
11.3
13.5
Precharge Floating Standby Current: CS ≥ VIH MIN, all banks
idle; CKE ≤ VIL MAX; tCK = tCK MIN ,address and other control
inputs changing once per clock cycle, VIN = VREF for DQ, DQS
and DM.
IDD2F
mA
1, 2
25.2
35
31
35
Precharge Quiet Standby Current: CS ≥ VIH MIN, all banks
idle; CKE ≥ VIH MIN; tCK = tCK MIN ,address and other control
inputs stable at ≥ VIH MIN or ≤ VIL MAX; VIN = VREF for DQ, DQS
and DM.
IDD2Q
24.7
11.4
45
35
15
60
30.4
13.5
54
40
20
70
mA
mA
mA
1, 2
1, 2
1, 2
Active Power-Down Standby Current: one bank active;
IDD3P power-down mode; CKE ≤ VIL MAX; tCK = tCK MIN;VIN = VREF for
DQ, DQS and DM.
Active Standby Current: one bank active; active / pre-
charge;CS ≥ VIH MIN; CKE ≥ VIH MIN; tRC = tRAS MAX; tCK = tCK
MIN; DQ, DM, and DQS inputs changing twice per clock cycle;
IDD3N
address and control inputs changing once per clock cycle
Operating Current: one bank active; Burst = 2; reads; continu-
ous burst; address and control inputs changing once per clock
cycle; DQ and DQS outputs changing twice per clock cycle; CL
= 2 for DDR200 and DDR266A, tCK = tCK MIN; IOUT = 0mA
IDD4R
105
91
150
130
134
115
190
170
mA
mA
1, 2
1, 2
Operating Current: one bank active; Burst = 2; writes; continu-
ous burst; address and control inputs changing once per clock
cycle; DQ and DQS inputs changing twice per clock cycle; CL =
IDD4W
2 for DDR200 and DDR266A, tCK = tCK MIN
IDD5
IDD6
Auto-Refresh Current: tRC = tRFC MIN, distributed refresh
mA
mA
1, 2
130
1.8
180
3
142
1.8
190
3
Self-Refresh Current:
CKE ≤ 0.2V; external clock on; tCK = tCK MIN
1, 2, 3
Operating Current: four bank; four bank interleaving with BL=4.
Refer to the following page for detailed test conditions
IDD7
192
250
246
300
mA
1, 2
1. IDD specifications are tested after the device is properly initialized and measured
at 100 MHz for DDR200 and 133 MHz for DDR266.
2. Input slew rate = 1V/ns.
3. Enables on-chip refresh and address counters
4. Test condition for typical values : VDD = 2.5V ,Ta = 25oC, test condition for maximum values: test limit at
VDD = 2.7V ,Ta = 10oC
10/01
Page 54 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Detailed Test Conditions for IDD1 and IDD7
IDD1 : Operating current : One bank operation
1. Only one bank is accessed with t
, Burst Mode, Address and Control inputs on NOP edge are changing once
RC(min)
per clock cycle. l = 0 mA
out
2. Timing patterns
- DDR200 (100Mhz, CL=2) : tCK = 10 ns, CL=2, BL=4, tRCD = 2 * tCK, tRAS = 5 * tCK
Setup: A0 N R0 N N P0 N
Read : A0 N R0 N N P0 N - repeat the same timing with random address changing
50% of data changing at every burst
- DDR266A (133Mhz, CL=2) : tCK = 7.5 ns, CL=2, BL=4, tRCD = 3 * tCK, tRC = 9 * tCK, tRAS = 5 * tCK
Setup: A0 N N R0 N P0 N N N
Read : A0 N N R0 N P0 N NN - repeat the same timing with random address changing
50% of data changing at every burst
3.Legend : A=Activate, R=Read, W=Write, P=Precharge, N=NOP
IDD7 : Operating current: Four bank operation
1. Four banks are being interleaved with t
, Burst Mode, Address and Control inputs on NOP edge are not
RC(min)
changing. l = 0 mA
out
2. Timing patterns
- DDR200 (100Mhz, CL=2) : tCK = 10 ns, CL=2, BL=4, tRRD = 2 * tCK, tRCD= 3 * tCK, Read with autoprecharge
Setup: A0 N A1 R0 A2 R1 A3 R2
Read : A0 R3 A1 R0 A2 R1 A3 R2- repeat the same timing with random address changing
50% of data changing at every burst
- DDR266A (133Mhz, CL=2) : tCK = 7.5 ns, CL=2, BL=4, tRRD = 2 * tCK, tRCD = 3 * tCK
Setup: A0 N A1 R0 A2 R1 A3 R2 N R3
Read : A0 N A1 R0 A2 R1 A3 R2 N R3 - repeat the same timing with random address changing
50% of data changing at every burst
3.Legend : A=Activate, R=Read, W=Write, P=Precharge, N=NOP
10/01
Page 55 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
AC Characteristics
AC Operating Conditions
(0 °C ≤ T ≤ 70 °C; V
= 2.5V ± 0.2V; V = 2.5V ± 0.2V) See Notes 5 ~ 11.
A
DDQ
DD
Symbol
Parameter/Condition
Min
Max
Unit
V
Notes
1, 2
VIH(AC) Input High (Logic 1) Voltage, DQ, DQS, and DM Signals
VIL(AC) Input Low (Logic 0) Voltage, DQ, DQS, and DM Signals
VID(AC) Input Differential Voltage, CK and CK Inputs
VREF + 0.35
VREF − 0.35
V
1, 2
0.7
VDDQ + 0.6
V
1, 2, 3
1, 2, 4
VIX(AC) Input Closing Point Voltage, CK and CK Inputs
0.5*VDDQ − 0.2 0.5*VDDQ + 0.2
V
1. Input slew rate = 1V/ns.
2. Inputs are not recognized as valid until VREF stabilizes.
3. VID is the magnitude of the difference between the input level on CK and the input level on CK.
4. The value of VIX is expected to equal 0.5*VDDQ of the transmitting device and must track variations in the DC level of the same.
5. All voltages referenced to VSS
.
6. Tests for AC timing, IDD, and electrical, AC and DC characteristics, may be conducted at nominal reference/supply voltage levels,
but the related specifications and device operation are guaranteed for the full voltage range specified.
7. The figure below represents the timing reference load used in defining the relevant timing parameters of the part. It is not intended
to be either a precise representation of the typical system environment nor a depiction of the actual load presented by a production
tester. System designers will use IBIS or other simulation tools to correlate the timing reference load to a system environment.
Manufacturers will correlate to their production test conditions (generally a coaxial transmission line terminated at the tester elec-
tronics).
8. AC timing and IDD tests may use a VIL to VIH swing of up to 1.5V in the test environment, but input timing is still referenced to VREF
(or to the crossing point for CK, CK), and parameter specifications are guaranteed for the specified AC input levels under normal
use conditions. The minimum slew rate for the input signals is 1V/ns in the range between VIL(AC) and VIH(AC)
.
9. The AC and DC input level specifications are as defined in the SSTL_2 Standard (i.e. the receiver effectively switches as a result of
the signal crossing the AC input level, and remains in that state as long as the signal does not ring back above (below) the DC input
LOW (HIGH) level.
10. For System Characteristics like Setup & Holdtime Derating for Slew Rate, I/O Delta Rise/Fall Derating,DDR SDRAM Slew Rate
Standards, Overshoot & Undershoot specification and Clamp V-I characteristics see the latest JEDEC specification for DDR com-
ponents
11. Notes 5-10 apply to the following Tables: Electrical Characteristics and DC Operating Conditions, AC Operating Conditions, IDD
Specifications and Conditions, and Electrical Characteristics and AC Timing.)
AC Output Load Circuit Diagram / Timing Reference Load
V
TT
50Ω
Output
(V
Timing Reference Point
)
OUT
30pF
10/01
Page 56 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Electrical Characteristics & AC Timing for DDR266/DDR200 - Absolute
Specifications
(0 °C ≤ T ≤ 70 °C; V
= 2.5V ± 0.2V; V = 2.5V ± 0.2V) (Part 1 of 3)
A
DDQ
DD
DDR266A
DDR200
-8
-7
Symbol
Parameter
Unit Notes
Min
− 0.75
− 0.75
0.45
Max
+ 0.75
+ 0.75
0.55
Min
Max
+ 0.8
+ 0.8
0.55
0.55
tAC
DQ output access time from CK/CK
− 0.8
− 0.8
0.45
0.45
ns
ns
tCK
tCK
ns
ns
ns
ns
ns
1-4
1-4
1-4
1-4
1-4
1-4
1-4
1-4
1-4
tDQSCK DQS output access time from CK/CK
tCH
tCL
CK high-level width
CK low-level width
Clock Half Period
0.45
0.55
tHP
tCK
tCK
tDH
tDS
tIPW
min (tCL, tCH)
min (tCL, tCH)
CL = 2.5
CL = 2.0
7
12
12
8
12
12
Clock cycle time
7.5
0.5
0.5
2.2
1.75
10
0.6
0.6
2.5
2
DQ and DM input hold time
DQ and DM input setup time
Control and Addr. input pulse width (each input)
ns 1-4,10
ns 1-4,10
tDIPW DQ and DM input pulse width (each input)
Data-out high-impedence time from
CK/CK
tHZ
− 0.75
− 0.75
0.75
+ 0.75
+ 0.75
1.25
− 0.8
− 0.8
0.75
+ 0.8
+ 0.8
1.25
ns 1-4, 5
ns 1-4, 5
Data-out low-impedence time from
CK/CK
tLZ
Write command to 1st DQS latching
transition
tDQSS
tCK
1-4
tDQSQ DQS-DQ skew (for DQS & associated DQ signals)
tQHS Data hold skew factor
+ 0.5
+ 0.6
ns
ns
ns
1-4
1-4
1-4
+ 0.75
+ 1.0
tQH
Data Output hold time from DQS
tHP-tQHS
tHP-tQHS
1. Input slew rate >=1V/ns for DDR266 and = 1V/ns for DDR200.
2. The CK/CK input reference level (for timing reference to CK/CK) is the point at which CK and CK cross: the
input reference level for signals other than CK/CK, is VREF. CK/CK slew rate are >= 1.0 V/ns.
3. Inputs are not recognized as valid until VREF stabilizes.
4. The Output timing reference level, as measured at the timing reference point indicated in AC Characteristics
(Note 3) is VTT
.
5. tHZ and tLZ transitions occur in the same access time windows as valid data transitions. These parameters are
not referred to a specific voltage level, but specify when the device is no longer driving (HZ), or begins driving
(LZ).
6. The maximum limit for this parameter is not a device limit. The device operates with a greater value for this
parameter, but system performance (bus turnaround) degrades accordingly.
7. The specific requirement is that DQS be valid (HIGH, LOW, or some point on a valid transition) on or before this
CK edge. A valid transition is defined as monotonic and meeting the input slew rate specifications of the device.
When no writes were previously in progress on the bus, DQS will be transitioning from Hi-Z to logic LOW. If a
previous write was in progress, DQS could be HIGH, LOW, or transitioning from HIGH to LOW at this time,
depending on tDQSS
.
8. A maximum of eight Autorefresh commands can be posted to any given DDR SDRAM device.
9. For each of the terms, if not already an integer, round to the next highest integer. tCK is equal to the actual sys-
tem clock cycle time.
10. These parameters guarantee device timing, but they are not necessarily tested on each device
11. Fast slew rate >= 1.0 V/ns , slow slew rate >= 0.5 V/ns and < 1V/ns for command/address and CK & CK slew
rate >1.0 V/ns, measured between VOH(ac) and VOL(ac)
10/01
Page 57 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Electrical Characteristics & AC Timing for DDR266/DDR200 - Absolute
Specifications
(0 °C ≤ T ≤ 70 °C; V
= 2.5V ± 0.2V; V = 2.5V ± 0.2V) (Part 2 of 3)
A
DDQ
DD
DDR266A
DDR200
-8
-7
Symbol
Parameter
Unit Notes
Min
0.35
0.2
0.2
14
Max
Min
Max
tDQSL,H DQS input low (high) pulse width (write cycle)
tDSS DQS falling edge to CK setup time (write cycle)
tDSH DQS falling edge hold time from CK (write cycle)
tMRD Mode register set command cycle time
tWPRES Write preamble setup time
0.35
0.2
0.2
16
tCK
tCK
tCK
ns
1-4
1-4
1-4
1-4
0
0
ns 1-4, 7
tCK 1-4, 6
tWPST Write postamble
0.40
0.25
0.9
1.0
0.9
1.0
0.9
0.40
45
0.60
0.40
0.25
1.1
1.1
1.1
1.1
0.9
0.40
50
0.60
tWPRE Write preamble
tCK
ns
1-4
fast slew rate
Address and control input setup
time
tIS
slow slew rate
ns
2-4,
10,11
fast slew rate
ns
Address and control input hold
time
tIH
slow slew rate
ns
tRPRE Read preamble
1.1
0.60
1.1
tCK
tCK
1-4
1-4
1-4
1-4
tRPST Read postamble
0.60
tRAS Active to Precharge command
120,000
120,000 ns
ns
tRC
Active to Active/Auto-refresh command period
65
70
Auto-refresh to Active/Auto-refresh
command period
tRFC
75
80
ns
1-4
tRCD Active to Read or Write delay
tRP Precharge command period
20
20
20
20
ns
ns
1-4
1-4
1. Input slew rate >=1V/ns for DDR266 and = 1V/ns for DDR200.
2. The CK/CK input reference level (for timing reference to CK/CK) is the point at which CK and CK cross: the
input reference level for signals other than CK/CK, is VREF. CK/CK slew rate are >= 1.0 V/ns.
3. Inputs are not recognized as valid until VREF stabilizes.
4. The Output timing reference level, as measured at the timing reference point indicated in AC Characteristics
(Note 3) is VTT
.
5. tHZ and tLZ transitions occur in the same access time windows as valid data transitions. These parameters are
not referred to a specific voltage level, but specify when the device is no longer driving (HZ), or begins driving
(LZ).
6. The maximum limit for this parameter is not a device limit. The device operates with a greater value for this
parameter, but system performance (bus turnaround) degrades accordingly.
7. The specific requirement is that DQS be valid (HIGH, LOW, or some point on a valid transition) on or before this
CK edge. A valid transition is defined as monotonic and meeting the input slew rate specifications of the device.
When no writes were previously in progress on the bus, DQS will be transitioning from Hi-Z to logic LOW. If a
previous write was in progress, DQS could be HIGH, LOW, or transitioning from HIGH to LOW at this time,
depending on tDQSS
.
8. A maximum of eight Autorefresh commands can be posted to any given DDR SDRAM device.
9. For each of the terms, if not already an integer, round to the next highest integer. tCK is equal to the actual sys-
tem clock cycle time.
10. These parameters guarantee device timing, but they are not necessarily tested on each device
11. Fast slew rate >= 1.0 V/ns , slow slew rate >= 0.5 V/ns and < 1V/ns for command/address and CK & CK slew
rate >1.0 V/ns, measured between VOH(ac) and VOL(ac)
10/01
Page 58 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Electrical Characteristics & AC Timing for DDR266/DDR200 - Absolute
Specifications
(0 °C ≤ T ≤ 70 °C; V
= 2.5V ± 0.2V; V = 2.5V ± 0.2V) (Part 3 of 3)
A
DDQ
DD
DDR266A
DDR200
-8
-7
Symbol
Parameter
Unit Notes
Min
15
Max
Min
Max
tRRD Active bank A to Active bank B command
15
15
ns
ns
1-4
1-4
tWR
Write recovery time
15
Auto precharge write recovery
+ precharge time
tDAL
(twr/tck) + (trp/tck)
tCK 1-4, 9
tWTR Internal write to read command delay
tXSNR Exit self-refresh to non-read command
tXSRD Exit self-refresh to read command
tREFI Average Periodic Refresh Interval
1
1
tCK
ns
1-4
1-4
1-4
75
80
200
200
tCK
7.8
7.8
µs 1-4, 8
1. Input slew rate >=1V/ns for DDR266 and = 1V/ns for DDR200.
2. The CK/CK input reference level (for timing reference to CK/CK) is the point at which CK and CK cross: the
input reference level for signals other than CK/CK, is VREF. CK/CK slew rate are >= 1.0 V/ns.
3. Inputs are not recognized as valid until VREF stabilizes.
4. The Output timing reference level, as measured at the timing reference point indicated in AC Characteristics
(Note 3) is VTT
.
5. tHZ and tLZ transitions occur in the same access time windows as valid data transitions. These parameters are
not referred to a specific voltage level, but specify when the device is no longer driving (HZ), or begins driving
(LZ).
6. The maximum limit for this parameter is not a device limit. The device operates with a greater value for this
parameter, but system performance (bus turnaround) degrades accordingly.
7. The specific requirement is that DQS be valid (HIGH, LOW, or some point on a valid transition) on or before this
CK edge. A valid transition is defined as monotonic and meeting the input slew rate specifications of the device.
When no writes were previously in progress on the bus, DQS will be transitioning from Hi-Z to logic LOW. If a
previous write was in progress, DQS could be HIGH, LOW, or transitioning from HIGH to LOW at this time,
depending on tDQSS
.
8. A maximum of eight Autorefresh commands can be posted to any given DDR SDRAM device.
9. For each of the terms, if not already an integer, round to the next highest integer. tCK is equal to the actual sys-
tem clock cycle time.
10. These parameters guarantee device timing, but they are not necessarily tested on each device
11. Fast slew rate >= 1.0 V/ns , slow slew rate >= 0.5 V/ns and < 1V/ns for command/address and CK & CK slew
rate >1.0 V/ns, measured between VOH(ac) and VOL(ac)
10/01
Page 59 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Electrical Characteristics & AC Timing for DDR266A - Applicable Specifications
Expressed in Clock Cycles (0 °C ≤ T ≤ 70 °C; V
= 2.5V ± 0.2V; V = 2.5V ± 0.2V)
A
DDQ
DD
DDR266A @ CL=2.5
Symbol
Parameter
Units
Notes
Min
2
Max
tMRD
tWPRE
tRAS
Mode register set command cycle time
tCK
tCK
tCK
tCK
1-5
1-5
1-5
1-5
Write preamble
0.25
6
Active to Precharge command
Active to Active/Auto-refresh command period
16000
tRC
9
Auto-refresh to Active/Auto-refresh
command period
tRFC
10
tCK
1-5
tRCD
tRP
tRRD
tWR
Active to Read or Write delay
3
3
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
1-5
1-45
1-5
1-5
1-5
1-5
1-5
1-5
Precharge command period
Active bank A to Active bank B command
Write recovery time
2
2
tDAL
tWTR
tXSNR
tXSRD
Auto precharge write recovery + precharge time
Internal write to read command delay
Exit self-refresh to non-read command
Exit self-refresh to read command
5
1
10
200
1. Input slew rate = 1V/ns
2. The CK/CK input reference level (for timing reference to CK/CK) is the point at which CK and CK cross: the input reference level for
signals other than CK/CK, is VREF.
3. Inputs are not recognized as valid until VREF stabilizes.
4. The Output timing reference level, as measured at the timing reference point indicated in AC Characteristics (Note 3) is VTT
.
5. tHZ and tLZ transitions occur in the same access time windows as valid data transitions. These parameters are not referred to a spe-
cific voltage level, but specify when the device is no longer driving (HZ), or begins driving (LZ).
10/01
Page 60 of 75
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Timing Diagrams
Data Input (Write) (Timing Burst Length = 4)
tDQSL
tDQSH
DQS
tDH
tDS
DI n
DQ
tDH
tDS
DM
DI n = Data In for column n.
3 subsequent elements of data in are applied in programmed order following DI n.
Don’t Care
Data Output (Read) (Timing Burst Length = 4)
DQS
tDQSQ max
tQH
DQ
tQH (Data output hold time from DQS)
tDQSQ and tQH are only shown once and are shown referenced to different edges of DQS, only for clarify of illustration.
.
tDQSQ and tQH both apply to each of the four relevant edges of DQS.
tDQSQ max. is used to determine the worst case setup time for controller data capture.
tQH is used to determine the worst case hold time for controller data capture.
10/01
Page 61 of 75
VDD
* VTT is not applied directly to the device, however tVTD must be
greater than or equal to zero to avoid device latchup.
VDDQ
** tMRD is required before any command can be applied and
200 cycles of CK are required before a Read command can be applied.
tVTD
The two Autorefresh commands may be moved to follow the first MRS,
but precede the second Precharge All command.
VTT (System*)
VREF
tCK
200 cycles of CK**
tCH
tMRD
tMRD
tRP
tRFC
tRFC
tMRD
200µs
tCL
CK
CK
tIH
tIS
LVCMOS LOW LEVEL
CKE
tIH
tIS
NOP
PRE
EMRS
MRS
PRE
AR
AR
MRS
ACT
Command
DM
tIH
tIS
CODE
CODE
CODE
CODE
CODE
RA
RA
BA
A0-A9, A11
A10
tIH
tIH
tIH
tIS
tIS
tIS
CODE
ALL BANKS
ALL BANKS
tIH
tIS
BA0=L
BA1=L
BA0=L
BA1=L
BA0=H
BA1=L
BA0, BA1
DQS
High-Z
High-Z
DQ
Power-up:
VDD and CK
stable
Extended Mode
Register Set
Load Mode
Register, Reset DLL
Load Mode
Register
(with A8 = L)
Don’t Care
tCK
tCH
tCL
C K
C K
tIH
tIS
tIS
tIS
tIS
tIS
CKE
tIH
VALID*
NOP
VALID
VALID
NOP
Command
tIH
VALID
ADDR
DQS
DQ
DM
Enter Power
Down Mode
Exit Power
Down Mode
No column accesses are allowed to be in progress at the time power down is entered.
* = If this command is a Precharge (or if the device is already in the idle state) then the power down mode
shown is Precharge power down. If this command is an Active (or if at least one row is already active), then
the power down mode shown is Active power down.
Don’t Care
tRP
tCH
tCL
tCK
tRFC
tRFC
CK
CK
tIH
tIS
VALID
VALID
NOP
CKE
tIH
tIS
NOP
PRE
NOP
NOP
AR
NOP
AR
NOP
ACT
RA
Command
A0-A8
RA
A9, A11,A12
A10
ALL BANKS
RA
ONE BANK
tIH
tIS
BANK(S)
BA
BA0, BA1
DQS
DQ
DM
PRE = Precharge; ACT = Active; RA = Row address; BA = Bank address; AR = Autorefresh.
NOP commands are shown for ease of illustration; other valid commands may be possible at these times.
DM, DQ, and DQS signals are all don’t care/high-Z for operations shown.
Don’t Care
Clock must be stable before exiting Self Refresh Mode
tRP
*
tCK
200 cycles
tCH
tCL
CK
CK
tIH
tIS
tIS
tIS
CKE
tIH
tXSRD, tXSRN
tIS
NOP
AR
NOP
VALID
Command
tIH
tIS
VALID
ADDR
DQS
DQ
DM
Enter Self
Exit Self
Refresh Mode
Refresh Mode
* = Device must be in the all banks idle state before entering Self Refresh Mode.
** = tXSNR is required before any non-read command can be applied, and tXSRD (200 cycles of CK).
are required before a Read command can be applied.
Don’t Care
tCL
tCK
tCH
tRP
C K
C K
tIH
tIS
tIH
VALID
NOP
VALID
NOP
VALID
NOP
CKE
Command
tIH
tIS
NOP
Read
tIH
NOP
PRE
NOP
NOP
ACT
RA
tIS
COL n
A0-A9, A11, A12
tIH
tIS
ALL BANKS
ONE BANK
RA
A10
AP
DIS
tIS
tIH
BA x
BA x*
BA x
BA0, BA1
DM
tLZ (min)
tRPRE
DQS
tHZ (min)
Case 1:
tAC/tDQSCK = min
tAC (min)
tRPST
tDQSCK (min)
CL=2
DQ
DO n
tLZ (max)
tRPRE
DQS
tHZ (max)
tRPST
Case 2:
AC/tDQSCK = max
tAC (max)
t
tLZ (max)
tDQSCK (max)
DQ
DO n
DO n = data out from column n.
3 subsequent elements of data out are provided in the programmed order following DO n.
DIS AP = Disable Auto Precharge.
* = Don’t care if A10 is High at this point.
PRE = Precharge; ACT = Active; RA = Row address; BA = Bank address.
NOP commands are shown for ease of illustration; other commands may be valid at these times.
Don’t Care
tCL
tCK
tRP
tCH
C K
C K
tIH
tIH
tIS
VALID
NOP
VALID
NOP
VALID
NOP
CKE
tIH
tIS
NOP
Read
tIH
NOP
NOP
NOP
NOP
ACT
RA
Command
tIS
A0-A9, A11, A12
COL n
tIH
tIS
RA
A10
EN AP
tIH
tIS
BA x
BA x
BA0, BA1
DM
tLZ (min)
tRPRE
DQS
tHZ (min)
tHZ (min)
Case 1:
tAC/tDQSCK = min
tAC (min)
tRPST
tDQSCK (min)
CL=2
DQ
DO n
tLZ (max)
tRPRE
DQS
tHZ (max)
tRPST
tDQSCK (max)
Case 2:
AC/tDQSCK = max
tAC (max)
t
tLZ (max)
DQ
DO n
DO n = data out from column n.
3 subsequent elements of data out are provided in the programmed order following DO n.
EN AP = enable Auto Precharge.
ACT = active; RA = row address.
Don’t Care
NOP commands are shown for ease of illustration; other commands may be valid at these times.
tCL
tCK
tCH
C K
C K
tRC
tIH
tIS
VALID
NOP
CKE
Command
tIH
tIS
NOP
ACT
tIH
NOP
Read
NOP
PRE
NOP
NOP
ACT
RA
tIS
RA
COL n
A0-A9, A11, A12
tIH
tIS
ALL BANKS
ONE BANK
A
RA
A10
DIS AP
BA x
tIH
tIS
BA x
BA x*
BA x
BA0, BA1
DM
tLZ (min)
tRPRE
tRP
DQS
tRCD
tHZ (min)
tLZ (min)
Case 1:
tAC (min)
tRAS
tRPST
tAC/tDQSCK = min
CL=2
tDQSCK (min)
DQ
DO n
tLZ (max)
tRPRE
DQS
tHZ (max)
Case 2:
AC/tDQSCK = max
tAC (max)
tRPST
tDQSCK (max)
t
tLZ (max)
DQ
DO n
DO n = data out from column n.
3 subsequent elements of data out are provided in the programmed order following DO n.
DIS AP = disable Auto Precharge.
* = Don’t care if A10 is High at this point.
Don’t Care
PRE = Precharge; ACT = Active; RA = Row address; BA = Bank address.
NOP commands are shown for ease of illustration; other commands may be valid at these times.
tCH
tCK
tWR
tCL
tRP
C K
C K
tIH
tIS
tIH
VALID
NOP
CKE
tIH
tIS
NOP
Write
NOP
NOP
NOP
PRE
NOP
ACT
RA
NOP
Command
tIH
tIS
COL n
A0-A9, A11, A12
tIH
tIS
ALL BANKS
ONE BANK
DIS AP
RA
BA
A10
tIH
tIS
BA x
BA x*
BA0, BA1
tDSH
tWPRE
tWPRES
tDQSH
tDQSL
tDQSS
tWPST
DQS
DQ
DIn
DM
tDQSS = min.
DIn = Data in for column n.
3 subsequent elements of data in are applied in the programmed order following DIn.
DIS AP = Disable Auto Precharge.
Don’t Care
* = Don’t care if A10 is High at this point.
PRE = Precharge; ACT = Active; RA = Row address; BA = Bank address.
NOP commands are shown for ease of illustration; other valid commands may be possible at these times.
tCH
tWR
tCK
tRP
tCL
C K
C K
tIH
tDAL
tIS
VALID
NOP
VALID
NOP
VALID
NOP
CKE
tIH
tIS
NOP
Write
NOP
NOP
NOP
ACT
NOP
Command
A0-A9, A11, A12
A10
tIH
tIS
COL n
RA
RA
tIH
tIS
EN AP
tIH
tIS
BA x
BA
BA0, BA1
tDSH
tWPRES
tDQSH
tDQSS
tDQSL
tWPST
DQS
DQ
DIn
DM
tWPRE
tDQSS = min.
DIn = Data in for column n.
3 subsequent elements of data in are applied in the programmed order following DIn.
EN AP = Enable Auto Precharge.
ACT = Active; RA = Row address; BA = Bank address.
NOP commands are shown for ease of illustration; other valid commands may be possible at these times.
Don’t Care
tCH
tCK
tCL
CK
CK
tIH
tIS
VALID
NOP
CKE
tIH
tRAS
tIS
NOP
ACT
NOP
Write
NOP
NOP
NOP
NOP
PRE
Command
tIH
tIS
A0-A9, A11, A12
RA
RA
Col n
tIH
tIS
ALL BANKS
ONE BANK
DIS AP
A10
tIH
tIS
BA x
BA x
BA x
BA0, BA1
tRCD
tDSH
tDQSL
tWPRES
tWR
tDQSH
tWPST
tDQSS
DQS
DQ
DIn
DM
tWPRE
tDQSS = min.
DI n = data in for column n.
3 subsequent elements of data in are applied in the programmed order following DI n.
DIS AP = Disable Auto Precharge.
Don’t Care
* = don’t care if A10 is High at this point.
PRE = Precharge; ACT = Active; RA = Row address.
NOP commands are shown for ease of illustration; other valid commands may be possible at these times.
tCH
tCK
tCL
CK
CK
tIH
tIS
VALID
NOP
CKE
tIH
tIS
NOP
Write
NOP
NOP
NOP
PRE
NOP
ACT
RA
NOP
Command
tIH
tIS
A0-A9, A11, A12
COL n
tIH
tIS
ALL BANKS
ONE BANK
DIS AP
RA
BA
A10
tIH
tIS
BA x
BA x*
BA0, BA1
tWR
tRP
tWPRES
tDSH
tDQSH
tWPST
tDQSL
tDQSS
DQS
DQ
DIn
DM
DI n = data in for column n.
3 subsequent elements of data in are applied in the programmed order following DI n (the second element of the 4 is masked).
DIS AP = Disable Auto Precharge.
* = Don’t care if A10 is High at this point.
Don’t Care
PRE = Precharge; ACT = Active; RA = Row address; BA = Bank address.
NOP commands are shown for ease of illustration; other valid commands may be possible at these times.
tDQSS = min.
HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
Package Dimensions
(400mil; 66 lead; Thin Small Outline Package)
Plastic Package, P-TSOPII-66
(400mil; 66 lead
)
Thin Small Outline Package
Gauge Plane
10,16±0,13
0,5±0,1
0,65 Basic
0,805 REF
0.1
Seating Plane
±0,08
0,3
11,76±0,2
22,22±0,13
TSOP66
Lead #1
10/01
Page 73 of 75
HYB25D256400/800AT
256-MBit Double Data Rata SDRAM
Write to Read: Minimum DQSS
Write to Read: Nominal DQSS
Write to Precharge Non-Interrupting
Write to Precharge Interrupting
Write to Precharge Minimum DQSS
Write to Precharge: Nominal DQSS
Precharge
36
37
38
39
40
41
42
43
44
45
47
TABLE OF CONTENT
Features
1
Description
Pin Configuration
Input/Output Functional Description
Block Diagram (32Mb x 4)
Block Diagram (16Mb x 8)
1
2
3
5
6
Power-Down
Truth Table 2: Clock Enable (CKE)
Truth Table 3: Current State, SameBank)
Truth Table 4: Current State,Different Bank
Functional Description
Initialization
7
7
8
Simplified State Diagram
49
Register Definition
Mode Register Operation
Burst Definition
Required CAS Latencies
Extended Mode Register
Extended Mode Register Definition
9
Operating Conditions
50
50
50
51
52
52
53
54
56
56
57
10
11
12
13
Absolute Maximum Ratings
Input and Output Capacitances
DC Electrical Operating Conditions
Pulldown Characteristics
Pullup Characteristics
Commands
14
14
14
14
14
14
14
15
15
15
15
16
16
Pulldown and Pullup Currents
IDD Specifications and Conditions
AC Characteristics
AC Output Load Circuit Diagram
Electrical Characteristics & AC Timing
Delesect, No Operation
Mode Register Set
Active
Read
Write
Precharge
Timing Diagrams
61
61
61
62
63
64
65
66
67
68
69
70
71
72
Auto Precharge
Burst Terminate
Auto Refresh
Data Input (Write)
Data Output (Read)
Initialize and Mode Register Sets
Power Down Mode
Auto Refresh Mode
Self Refresh
Truth Table 1a: Commands
Truth Table 1b: DM Operation
Self Refresh Mode
Read without Auto Precharge
Read with Auto Precharge
Bank Read Access
Write without Auto Precharge.
Write with Auto Precharge
Bank Write Access
Operations
17
Activating a Specific Row in a Specific Bank 17
tRCD and tRRD Definition
Read Command
18
19
20
21
22
23
25
26
27
28
30
31
32
33
34
35
Read Burst
Consecutive Read Bursts
Non-Consecutive Read Bursts
Random Read Accesses
Terminating a Read Burst
Read to Write
Write DM Operation
Package Dimensions
Table of Content
Secuity Information
73
74
75
Read to Precharge
Write Command
Write Burst (Burst Length = 4)
Write to Write (Burst Length = 4)
Write to Write
Random Write Cycles
Write to Read
Write to Read Interrupting
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HYB25D256400/800AT
256-Mbit Double Data Rate SDRAM
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Ciritcal components of INFINEON Technologies, may only be used in life-
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support devices or systems with the express written approval of INFINEON
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whose failure can reasonably be expected to cause the failure of that life-
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10/01
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