MSM548262-60JS [OKI]
262,144-Word x 8-Bit Multiport DRAM; 262,144字×8位的多端口DRAM型号: | MSM548262-60JS |
厂家: | OKI ELECTRONIC COMPONETS |
描述: | 262,144-Word x 8-Bit Multiport DRAM |
文件: | 总37页 (文件大小:459K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
E2L0016-17-Y1
This version: Jan. 1998
Previous version: Dec. 1996
¡ Semiconductor
MSM548262
262,144-Word ¥ 8-Bit Multiport DRAM
DESCRIPTION
The MSM548262 is a 2-Mbit CMOS multiport DRAM composed of a 262,144-word by 8-bit
dynamic RAM, and a 512-word by 8-bit SAM. Its RAM and SAM operate independently and
asynchronously.
It supports three types of operations: random access to RAM port, high speed serial access to
SAM port, and bidirectional transfer of data between any selected row in the RAM port and the
SAM port. In addition to the conventional multiport DRAM operating modes, the MSM548262
features block write, flash write functions on the RAM port and a split data transfer capability
on the SAM port. The SAM port requires no refresh operation because it uses static CMOS flip-
flops.
FEATURES
• RAS only refresh
• Single power supply: 5 V ±10%
• Full TTL compatibility
• Multiport organization
RAM : 256K word ¥ 8 bits
SAM : 512 word ¥ 8 bits
• Fast page mode
• CAS before RAS refresh
• Hidden refresh
• Serial read/write
• 512 tap location
• Bidirectional data transfer
• Split transfer
• Write per bit
• Masked write transfer
• Refresh: 512 cycles/8 ms
• Masked flash write
• Masked block write
• Package options:
40-pin 400 mil plastic SOJ
(SOJ40-P-400-1.27)
(Product : MSM548262-xxJS)
44/40-pin 400 mil plastic TSOP (Type II)(TSOPII44/40-P-400-0.80-K)(Product : MSM548262-xxTS-K)
xx indicates speed rank.
PRODUCT FAMILY
Access Time
Cycle Time
RAM SAM
Power Dissipation
Family
MSM548262-60
RAM
60 ns
70 ns
80 ns
SAM
Operating
Standby
8 mA
17 ns 120 ns 22 ns
17 ns 140 ns 22 ns
20 ns 150 ns 25 ns
140 mA
130 mA
120 mA
MSM548262-70
MSM548262-80
8 mA
8 mA
1/37
¡ Semiconductor
MSM548262
PIN CONFIGURATION (TOP VIEW)
VCC
SC
1
2
3
4
5
6
7
8
9
44 VSS
1
2
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
VCC
SC
VSS
43 SDQ8
42 SDQ7
41 SDQ6
40 SDQ5
39 SE
38 DQ8
37 DQ7
36 DQ6
35 DQ5
SDQ8
SDQ7
SDQ6
SDQ5
SE
SDQ1
SDQ2
SDQ3
SDQ4
TRG
DQ1
DQ2
DQ3 10
3
SDQ1
SDQ2
SDQ3
SDQ4
TRG
DQ1
DQ2
DQ3
DQ4
VSS
4
5
6
7
DQ8
DQ7
DQ6
DQ5
VSS
8
DQ4 13
VSS 14
WE 15
RAS 16
A8 17
A7 18
A6 19
A5 20
A4 21
VCC 22
32 VSS
31 DSF
30 NC
29 CAS
28 QSF
27 A0
26 A1
25 A2
24 A3
23 VSS
9
10
11
12
13
14
15
16
17
18
19
20
DSF
NC
WE
RAS
A8
CAS
QSF
A0
A7
44/40-Pin Plastic TSOP (II)
(K Type)
A6
A1
A5
A2
A4
A3
VCC
VSS
40-Pin Plastic SOJ
Pin Name
A0 - A8
DQ1 - DQ8
SDQ1 - SDQ8
RAS
Pin Name
SC
Function
Address Input
Function
Serial Clock
RAM Inputs/Outputs
SAM Inputs/Outputs
Row Address Strobe
SE
SAM Port Enable
Special Function Input
Special Function Output
Power Supply (5 V)
Ground (0 V)
DSF
QSF
VCC
CAS
Column Address Strobe
Write Enable
WE
VSS
TRG
NC
Transfer/Output Enable
No Connection
Note:
ThesamepowersupplyvoltagemustbeprovidedtoeveryV pin,andthesameGND
CC
voltage level must be provided to every V pin.
SS
2/37
Column
Address
Buffer
Block Write
Control
Column Mask
Register
Column Decoder
Sense Amp.
RAM Input
Buffer
I/O Control
Color Register
Mask Register
DQ 1 - 8
RAM Output
Buffer
Row
Address
Buffer
512 ¥ 512 ¥ 8
RAM ARRAY
Flash Write
Control
SAM Input
A0 - A8
Refresh
Counter
RAS
CAS
TRG
WE
DSF
SC
Gate
SAM
Gate
SAM
Buffer
SDQ 1 - 8
SAM Output
Buffer
Timing
Serial Decoder
Generator
SAM
Address
Buffer
SAM Address
SE
QSF
Counter
VCC
VSS
SAM Stop
Control
¡ Semiconductor
MSM548262
ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings
(Note: 1)
Parameter
Input Output Voltage
Output Current
Symbol
VT
Condition
Ta = 25°C
Ta = 25°C
Ta = 25°C
—
Rating
–1.0 to 7.0
50
Unit
V
IOS
mA
W
Power Dissipation
PD
1
Topr
Tstg
Operating Temperature
Storage Temperature
0 to 70
–55 to 150
°C
—
°C
Recommended Operating Conditions
(Ta = 0°C to 70°C) (Note: 2)
Parameter
Power Supply Voltage
Input High Voltage
Input Low Voltage
Symbol
VCC
Min.
4.5
Typ.
5.0
—
Max.
5.5
Unit
V
V
V
VIH
2.4
6.5
VIL
–1.0
—
0.8
Capacitance
(VCC = 5 V 10ꢀ% f = 1 MHꢁ% Ta = 25°C)
Parameter
Input Capacitance
Symbol
Ci
Min.
—
Max.
Unit
pF
8
9
9
Input/Output Capacitance
Output Capacitance
Cio
—
pF
Co(QSF)
—
pF
Note: This parameter is periodically sampled and is not 100% tested.
DC Characteristics 1
Parameter
Output "H" Level Voltage
Output "L" Level Voltage
Symbol
VOH
Condition
IOH = –1 mA
IOL = 2.1 mA
Min.
2.4
Max.
—
Unit
V
VOL
—
0.4
0 £ VIN £ VCC
All other pins not
under test = 0 V
Input Leakage Current
Output Leakage Current
ILI
–10
–10
10
10
mA
0 £ VOUT £ 5.5 V
Output Disable
ILO
4/37
¡ Semiconductor
MSM548262
DC Characteristics 2
(VCC = 5 V 10ꢀ% Ta = 0°C to 70°C)
-60
-70
-80
Item (RAM)
SAM
Symbol
Unit Note
Max. Max. Max.
Operating Current
Standby
Active
ICC1
95
140
8
85
130
8
75
120
8
3% 4
17
(RAS% CAS Cycling% tRC = tRC min.)
Standby Current
ICC1
ICC2
ICC2
ICC3
ICC3
ICC4
ICC4
ICC5
ICC5
ICC6
ICC6
ICC7
ICC7
ICC8
ICC8
A
Standby
Active
(RAS% CAS = VIH)
A
60
55
50
3% 4
3% 4
17
RAS Only Refresh Current
(RAS Cycling% CAS = VIH% tRC = tRC min.)
Page Mode Current
Standby
Active
95
85
75
A
140
75
130
70
120
65
Standby
Active
3% 4
(RAS = VIL% CAS Cycling% tPC = tPC min.)
CAS before RAS Refresh Current
(RAS Cycling% CAS before RAS% tRC = tRCmin.)
Data Transfer Current
A
140
95
130
85
120
75
18
mA
Standby
Active
3% 4
A
140
95
130
85
120
75
3% 4
3% 4
17
Standby
Active
(RAS% CAS Cycling% tRC = tRC min.)
Flash Write Current
A
140
95
130
85
120
75
Standby
Active
3% 4
3% 4
3% 4
3% 4
(RAS% CAS Cycling% tRC = tRC min.)
Block Write Current
A
140
95
130
85
120
75
Standby
Active
(RAS% CAS Cycling% tRC = tRC min.)
A
140
130
120
5/37
¡ Semiconductor
MSM548262
AC Characteristics (1/3)
-60
-70
-80
Parameter
Symbol
Unit Note
Min. Max. Min. Max. Min. Max.
Random Read or Write Cycle Time
Read Modify Write Cycle
tRC
tRWC
tPC
120
170
40
85
—
—
—
—
0
—
—
—
—
60
30
15
35
15
35
—
140
185
45
90
—
—
—
—
0
—
—
—
—
70
35
20
40
20
35
—
150
195
50
90
—
—
—
—
0
—
—
—
—
80
40
25
45
20
35
—
ns
ns
Fast Page Mode Cycle Time
Fast Page Mode Read Modify Write Cycle Time
Access Time from RAS
ns
tPRWC
tRAC
tAA
ns
ns 8% 14
ns 8% 14
ns 8% 15
ns 8% 15
Access Time from Column Address
Access Time from CAS
tCAC
tCPA
tOFF
tT
Access Time from CAS Precharge
Output Buffer Turn-off Delay
Transition Time (Rise and Fall)
RAS Precharge Time
ns
ns
ns
10
7
3
3
3
tRP
50
60
60
RAS Pulse Width
tRAS
tRASP
tRSH
tCSH
tCAS
tRCD
tRAD
tRAL
tCRP
tCP
60 10k 70 10k 80 10k ns
60 100k 70 100k 80 100k ns
RAS Pulse Width (Fast Page Mode Only)
RAS Hold Time
15
60
—
—
20
70
—
—
25
80
—
—
ns
ns
CAS Hold Time
CAS Pulse Width
15 10k 20 10k 25 10k ns
RAS to CAS Delay Time
20
15
30
10
10
0
45
30
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
20
15
35
10
10
0
50
35
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
20
15
40
10
10
0
55
40
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
14
14
RAS to Column Address Delay Time
Column Address to RAS Lead Time
CAS to RAS Precharge Time
CAS Precharge Time (Fast Page Mode)
Row Address Set-up Time
tASR
tRAH
tASC
tCAH
tAR
Row Address Hold Time
10
0
10
0
10
0
Column Address Set-up Time
Column Address Hold Time
Column Address Hold Time referenced to RAS
Read Command Set-up Time
Read Command Hold Time
Read Command Hold Time referenced to RAS
Write Command Set-up Time
Write Command Hold Time
Write Command Hold Time referenced to RAS
Write Command Pulse Width
Write Command to RAS Lead Time
Write Command to CAS Lead Time
Data Set-up Time
10
50
0
10
55
0
12
55
0
tRCS
tRCH
tRRH
tWCS
tWCH
tWCR
tWP
0
0
0
11
11
13
0
0
0
0
0
0
10
50
10
15
15
0
12
55
12
20
20
0
15
55
15
20
20
0
tRWL
tCWL
tDS
12
12
Data Hold Time
tDH
10
50
12
55
15
55
Data Hold Time referenced to RAS
tDHR
6/37
¡ Semiconductor
MSM548262
AC Characteristics (2/3)
-60
-70
-80
Parameter
Symbol
Unit Note
Min. Max. Min. Max. Min. Max.
RAS to WE Delay Time
tRWD
tAWD
tCWD
tDZC
tDZO
tOEA
tOEZ
tOEH
tROH
tCSR
tCHR
tRPC
tREF
tWSR
tRWH
tFSR
tRFH
tFHR
tFSC
tCFH
tMS
80
50
35
0
—
—
—
—
—
15
10
—
—
—
—
—
8
90
55
40
0
—
—
—
—
—
20
10
—
—
—
—
—
8
100
65
45
0
—
—
—
—
—
20
10
—
—
—
—
—
8
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ms
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
13
13
13
Column Address to WE Delay Time
CAS to WE Delay Time
Data to CAS Delay Time
Data to TRG Delay Time
0
0
0
Access Time from TRG
—
0
—
0
—
0
Output Buffer Turn-off Delay from TRG
TRG Command Hold Time
10
10
10
10
0
10
15
10
10
0
10
15
10
10
0
RAS Hold Time referenced to TRG
CAS Set-up Time for CAS before RAS Cycle
CAS Hold Time for CAS before RAS Cycle
RAS Precharge to CAS Active Time
Refresh Period
—
0
—
0
—
0
WE Set-up Time
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
WE Hold Time
10
0
10
0
12
0
DSF Set-up Time referenced to RAS
DSF Hold Time referenced to RAS (1)
DSF Hold Time referenced to RAS (2)
DSF Set-up Time referenced to CAS
DSF Hold Time referenced to CAS
Write Per Bit Mask Data Set-up Time
Write Per Bit Mask Data Hold Time
TRG High Set-up Time
10
50
0
10
55
0
12
55
0
10
0
10
0
12
0
tMH
10
0
10
0
12
0
tTHS
tTHH
tTLS
tTLH
tRTH
tATH
tCTH
tTRP
tTP
TRG High Hold Time
10
0
10
0
12
0
TRG Low Set-up Time
TRG Low Hold Time
10 10k 10 10k 12 10k ns
50 10k 60 10k 65 10k ns
TRG Low Hold Time referenced to RAS
TRG Low Hold Time referenced to Column Address
TRG Low Hold Time referenced to CAS
TRG to RAS Precharge Time
20
15
50
20
60
40
20
5
—
—
—
—
—
—
—
—
—
—
30
25
20
60
20
70
45
20
5
—
—
—
—
—
—
—
—
—
—
40
30
25
60
20
80
45
25
5
—
—
—
—
—
—
—
—
—
—
40
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
TRG Precharge Time
RAS to First SC Delay Time (Read Transfer)
Column Address to First SC Delay Time
CAS to First SC Delay Time (Read Transfer)
Last SC to TRG Lead Time
TRG to First SC Delay Time (Read Transfer)
Last SC to RAS Set-up Time (Serial Input)
Serial Output Buffer Turn-off Delay from RAS
tRSD
tASD
tCSD
tTSL
tTSD
tSRS
tSDZ
15
20
10
15
25
10
15
25
10
10
7/37
¡ Semiconductor
MSM548262
AC Characteristics (3/3)
-60
-70
-80
Parameter
Symbol
Unit Note
Min. Max. Min. Max. Min. Max.
SC Cycle Time
tSCC
tSC
22
5
—
—
—
17
—
17
—
—
20
—
—
25
25
30
70
—
—
—
—
—
—
—
—
—
22
5
—
—
—
17
—
17
—
—
20
—
—
25
25
35
75
—
—
—
—
—
—
—
—
—
25
7
—
—
—
20
—
20
—
—
20
—
—
25
25
35
75
—
—
—
—
—
—
—
—
—
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
SC Pulse Width (SC High Time)
SC Precharge Time (SC Low Time)
Access Time from SC
tSCP
tSCA
tSOH
tSEA
tSE
5
5
7
—
5
—
5
—
5
9
19
9
Serial Output Hold Time from SC
Access Time from SE
—
10
10
0
—
10
10
0
—
10
10
0
SE Pulse Width
SE Precharge Time
tSEP
tSEZ
tSTS
tSTH
tSQD
tTQD
tCQD
tRQD
tSDD
tSDS
tSDH
tSZE
tSZS
tSWS
tSWH
tSWIS
tSWIH
Serial Output Buffer Turn-off Delay from SE
Split Transfer Set-up Time
Split Transfer Hold Time
SC-QSF Delay Time
10
25
25
—
—
—
—
30
0
25
25
—
—
—
—
40
0
30
30
—
—
—
—
40
0
TRG-QSF Delay Time
CAS-QSF Delay Time
RAS-QSF Delay Time
RAS to Serial Input Delay Time
Serial Input Set-up Time
Serial Input Hold Time
10
0
10
0
12
0
Serial Input to SE Delay Time
Serial Input to First SC Delay Time
Serial Write Enable Set-up Time
Serial Write Enable Hold Time
Serial Write Disable Set-up Time
Serial Write Disable Hold Time
0
0
0
0
0
0
10
0
10
0
12
0
10
10
12
8/37
¡ Semiconductor
MSM548262
Notes: 1. Exposure beyond the "Absolute Maximum Ratings" may cause permanent damage
to the device.
2. All voltages are referenced to V .
SS
3. These parameters depend on the cycle rate.
4. These parameters depend on output loading. Specified values are obtained with the
output open.
5. An initial pause of 200 ms is required after power up followed by any 8 RAS cycles
(TRG = "high") and any 8 SC cycles before proper device operation is achieved.
In the case of using an internal refresh counter, a minimum of 8 CAS before RAS
cycles instead of 8 RAS cycles are required.
6. AC measurements assume t = 5 ns.
T
7. V (Min.)andV (Max.)arereferencelevelsformeasuringtimingofinputsignals.
IH
IL
Also, transition times are measured between V and V .
IH
IL
8. RAM port outputs are measured with a load equivalent to 1 TTL load and 50 pF.
DOUT reference levels : V /V = 2.0 V/0.8 V.
OH
OL
9. SAM port outputs are measured with a load equivalent to 1 TTL load and 30 pF.
DOUT reference levels : V /V = 2.0 V/0.8 V.
OH
OL
10. t
(Max.), t
(Max.), t
(Max.) and t
(Max.) define the time at which the
OFF
OEZ
SDZ
SEZ
outputsachievetheopencircuitcondition, andarenotreferencedtooutputvoltage
levels. This parameter is sampled and not 100% tested.
11. Either t
or t
must be satisfied for a read cycle.
RCH
RRH
12. These parameters are referenced to CAS leading edge of early write cycles, and to
WE leading edge in TRG controlled write cycles and read modify write cycles.
13. t
, t
, t
and t
are not restrictive operating parameters.
AWD
WCS RWD CWD
They are included in the data sheet as electrical characteristics only.
If t ≥ t (Min.), the cycle is an early write cycle, and the data out pin will
WCS
WCS
remain open circuit throughout the entire cycle; If t
≥t
(Min.), t
≥t
RWD RWD
CWD CWD
(Min.) and t
≥ t
(Min.), the cycle is a read modify write cycle, and the data
AWD AWD
out will contain data read from the selected cell; If neither of the above sets of
conditions are satisfied, the condition of the data out is indeterminate.
14. Operation within the t
(Max.) limit ensures that t
(Max.) can be met.
RCD
RAC
t
(Max.)isspecifiedasareferencepointonly:Ift
(Max.) limit, then access time is controlled by t
isgreaterthanthespecified
RCD
RCD
t
.
RCD
CAC
15. Operation within the t
(Max.) limit ensures that t
(Max.) can be met. t
RAD
RAC
RAD
RAD
(Max.)isspecifiedasareferencepointonly:Ift
isgreaterthanthespecifiedt
RAD
(Max.) limit, then access time is controlled by t
16. Input levels at the AC testing are 3.0 V/0 V.
.
AA
17. Address (A0 - A8) may be changed two times or less while RAS = V .
IL
18. Address (A0 - A8) may be changed once or less while CAS = V and RAS = V .
IH
IL
19. This is guaranteed by design. (t
/t
= t
/t
- output transition time)
SOH COH
SCA CAC
This parameter is not 100% tested.
9/37
¡ Semiconductor
MSM548262
TIMING WAVEFORM
Read Cycle
tRC
tRAS
tRP
RAS
tCSH
tRSH
tCAS
tCRP
tRCD
CAS
tAR
tRAD
tRAH
tRAL
tASR
Row
tASC
tCAH
Address
DSF
Column
tFHR
tFSR tRFH
tFSC
tCFH
tRCH
tRRH
tRCS
WE
tCAC
tOFF
tRAC
tAA
Open
DQ1 - 8
Valid Data
tROH
tTHS
tTHH
tOEA
tOEZ
TRG
"H" or "L"
10/37
¡ Semiconductor
MSM548262
Fast Page Mode Read Cycle
tRASP
tRP
RAS
tCSH
tPC
tRSH
tCAS
tCRP
tRCD
tCAS
tCP
tCAS
tCP
CAS
Address
DSF
tAR
tRAD
tRAH
tRAL
tASR
Row
tASC tCAH
Column
tASC tCAH
Column
tASC tCAH
Column
tFHR
tFSC
tFSC
tCFH
tFSR tRFH
tFSC tCFH
tCFH
tRCH
tRCS
tRCS
tRCS
tRRH
tRCH
tRCH
WE
tCAC
tAA
tCAC
tCAC
tAA
tAA
tOFF
tOFF
tOFF
Valid
Valid
Valid
DQ1 - 8
TRG
Open
Data
Data
Data
tRAC
tCPA
tCPA
tTHS
tTHH
tOEA
tOEZ
tOEA tOEZ
tOEA tOEZ
"H" or "L"
11/37
¡ Semiconductor
MSM548262
Write Cycle Function Table
RAS Falling Edge
CAS Falling Edge
Code
A
C
D
B
E
Function
DSF WE
DQ
DSF
DQ
RWM
BWM
FWM
RW
0
0
1
0
0
1
0
0
0
1
1
1
Write Mask
0
1
X
0
1
1
Valid Data
Column Mask
X
Masked Write
Write Mask
Masked Block Write
Masked Flash Write
Normal Write
Write Mask
X
X
X
Valid Data
Column Mask
Color Data
BW
Block Write
LCR
Load Color Register
WRITE MASK DATA: "Low" = Mask, "High" = No Mask
Column Mask Data
DQ1 - 4
DQ1
Column Mask Data
Column 0 (A0 = 0% A1 = 0)
Column 1 (A0 = 1% A1 = 0)
Column 2 (A0 = 0% A1 = 1)
Column 3 (A0 = 1% A1 = 1)
DQ2
Low: Mask
DQ3
High: No Mask
DQ4
12/37
¡ Semiconductor
MSM548262
Early Write Cycle
tRC
tRAS
tRP
RAS
tCSH
tRSH
tCAS
tCRP
tRCD
CAS
tAR
tRAD
tRAH
tRAL
tASR
tASC
tCAH
Address
DSF
Row
Column
tFHR
tFSC
tFSR
tRFH
tCFH
A
B
tCWL
tRWL
tWSR tRWH
C
tWP
WE
tWCR
tWCS
tDHR
tDS
tWCH
tMS
tMH
tDH
DQ1 - 8
D
E
tTHS
tTHH
TRG
"H" or "L"
13/37
¡ Semiconductor
MSM548262
Late Write Cycle
tRC
tRAS
tRP
RAS
tCSH
tRSH
tCAS
tCRP
tRCD
CAS
tAR
tRAD
tRAH
tRAL
tASR
tASC
tCAH
Address
DSF
Row
Column
tFHR
tFSC
tFSR
tRFH
tCFH
A
B
tCWL
tRWL
tWSR tRWH
C
tRCS
tWP
WE
tWCR
tDHR
tMS
tMH
tDS
tDH
DQ1 - 8
TRG
D
E
tTHS
tOEH
"H" or "L"
14/37
¡ Semiconductor
MSM548262
Read Modify Write Cycle
tRWC
tRAS
tRP
RAS
tCSH
tRSH
tCAS
tCRP
tRCD
CAS
tAR
tRAD
tRAH
tRAL
tASR
Row
tASC
tCAH
Address
DSF
Column
tAWD
tFHR
tFSR
tRFH
tFSC
tCFH
A
B
tCWL
tRWL
tWP
tWSR tRWH
C
tRCS
tCWD
tCAC
WE
tRWD
tRAC
tMS
tMH tDZC
tDS
tDH
Valid
DQ1 - 8
TRG
D
E
Data
tDZO
tOEZ
tTHS
tTHH
tOEA
tOEH
"H" or "L"
15/37
¡ Semiconductor
MSM548262
Fast Page Mode Early Write Cycle
tRASP
tRP
RAS
tCSH
tPC
tCAS
tRSH
tCAS
tCRP
tRCD
tCAS
tCP
tCP
CAS
Address
DSF
tAR
tASC
Column
tRAL
tCAH
tRAD
tRAH
tASR
tCAH
tASC
tCAH
tASC
Row
Column
Column
tFHR
tFSC tCFH
tFSR
tWSR
tMS
tRFH
tFSC tCFH
tFSC tCFH
B
A
B
B
tCWL
tWCH
tWP
tCWL
tCWL
tWCH
tWP
tRWH
tWCS
tWCS
tWCS
tWCH
tWP
WE
C
tMH
tDS tDH
E
tDS
tDH
tDS
tDH
DQ1 - 8
TRG
D
E
E
tTHS
tTHH
"H" or "L"
16/37
¡ Semiconductor
MSM548262
Fast Page Mode Read Modify Write Cycle
tRASP
tRP
RAS
tCSH
tPRWC
tCAS
tRSH
tCAS
tCRP
tRCD
tCAS
tCP
tCP
CAS
Address
DSF
tAR
tRAL
tCAH
tRAD
tASC
tASR
tRAH
tCAH
Column
tASC
tCAH
tASC
Row
Column
Column
tFHR
tFSC tCFH
tFSR
tRFH
tFSC tCFH
B
tFSC tCFH
B
A
B
tCWL
tAWD
tCWL
tAWD
tCWL
tAWD
tWSR
tRWH
WE
C
tRCS
tCWD
tCWD
tCWD
tWP
tWP
tWP
tCAC
tCAC
tCAC
tDH
tDH
tDH
tAA
tAA
tAA
tMS
tMH
tDS
tDS
tDS
Out In
tOEZ
Out In
tOEZ
Out In
tOEZ
DQ1 - 8
D
tTHS
tOEA
tOEA
tOEA
tTHH
TRG
"H" or "L"
17/37
¡ Semiconductor
MSM548262
RAS Only Refresh Cycle
tRC
tRAS
tRP
RAS
tCRP
tRPC
CAS
tASR
tRAH
Address
DSF
Row
tFSR
tRFH
WE
Open
DQ1 - 8
TRG
tTHS
tTHH
"H" or "L"
18/37
¡ Semiconductor
MSM548262
CAS before RAS Refresh Cycle
tRC
tRP
tRAS
tRP
RAS
tRPC
tCSR tCHR
tRPC
CAS
Address
DSF
Inhibit Falling Transition
WE
tOFF
Open
DQ1 - 8
TRG
"H" or "L"
19/37
¡ Semiconductor
MSM548262
Hidden Refresh Cycle
tRC
tRAS
tRP
tRAS
RAS
tCRP
tRCD
tRSH
tCHR
CAS
tAR
tRAD
tRAH
tRAL
tCAH
tASC
tASR
Address
DSF
Row
Column
tCFH
tFHR
tFSC
tFSR
tRFH
tRCS
tRRH
WE
tCAC
tAA
tOFF
Open
DQ1 - 8
TRG
Valid Data
tRAC
tTHS tTHH
tOEA
tOEZ
"H" or "L"
20/37
¡ Semiconductor
MSM548262
Read Transfer 1
tRC
tRAS
tRP
RAS
tCSH
tRSH
tCAS
tRCD
CAS
tAR
tRAD
tRAH
tRAL
tASC
SAM Start
tASR
tCAH
Address
DSF
Row
tFSR tRFH
tWSR tRWH
WE
tASD
tCSD
DQ1 - 8
TRG
Open
tRSD
tTRP
tTP
tTLS
tTLH
tSRS
tTSD
tSCC
tSC
tSCP
tSC
SC
Note 2
tSCA
tSOH
tSIS
tSZS
tSCA
tSIH
Din
SDQ1 - 8
QSF
Data Out
tTQD
tCQD
tRQD
Note 3
Note 3
"H" or "L"
Note 1: SE = "L"
Note 2: There must be no rising transitions
Note 3: QSF = "L"-- Lower SAM (0 - 255) is active
QSF = "H"-- Upper SAM (256 - 511) is active
21/37
¡ Semiconductor
MSM548262
Read Transfer 2 (Real Time Read Transfer)
tRC
tRAS
tRP
RAS
tCSH
tRSH
tCAS
tRCD
CAS
tAR
tRAD
tRAH
tRAL
tASC
tASR
Row
tCAH
Address
DSF
SAM Start
tFSR tRFH
tWSR tRWH
WE
tCTH
tATH
DQ1 - 8
TRG
Open
tTRP
tTP
tTLS
tRTH
tSCC
tTSL
tTSD
tSCP
tSC
SC
tSCA
tSOH
tSCA
tSOH
SDQ1 - 8
QSF
Data Out
Data Out
Data Out
Data Out
tTQD
Note 2
Note 2
"H" or "L"
Note 1: SE = "L"
Note 2: QSF = "L"-- Lower SAM (0 - 255) is active
QSF = "H"-- Upper SAM (256 - 511) is active
22/37
¡ Semiconductor
MSM548262
Split Read Transfer
tRC
tRAS
tRP
RAS
tCSH
tRSH
tCAS
tRCD
CAS
tAR
tRAD
tRAH
tRAL
tASC
SAM Start Sj
tASR
tCAH
Address
DSF
Row
tFSR tRFH
tWSR tRWH
WE
tCTH
tATH
DQ1 - 8
TRG
Open
tRTH
tTLS
tTLH
tSTS
tSCC
tSCP
tSC
511
S i
254
255
Sj+256
(S j)
SC
(255)
(Si+256)
tSCA
(510)
(511)
tSCA
tSOH
tSOH
SDQ1 - 8
QSF
Data Out
tSQD
Data Out
Data Out
Data Out
Data Out
Data Out
tSQD
Note 2
Note 2
Note 2
"H" or "L"
Note 1: SE = "L"
Note 2: QSF = "L"-- Lower SAM (0 - 255) is active
QSF = "H"-- Upper SAM (256 - 511) is active
Note 3: Si is the SAM start address in before SRT
23/37
¡ Semiconductor
MSM548262
Masked Write Transfer
tRC
tRAS
tRP
RAS
CAS
tCSH
tRSH
tCAS
tRCD
tAR
tRAD
tRAH
tRAL
tASC
SAM Start
tASR
Row
tCAH
Address
DSF
tFSR tRFH
tWSR tRWH
WE
tCSD
tMS
tMH
DQ1 - 8
TRG
Open
Mask Data
tRSD
tTLS
tTLH
tSRS
tSCC
tSC
tSCP
tSC
SC
Note 2
tSDZ
tSDS
tSDH
tSDS
tSDH
Data In
tSOH
SDQ1 - 8
QSF
Dout
Dout
tRQD
Data In
tSDD
tCQD
Note 3
Note 3
"H" or "L"
Note 1: SE = "L"
Note 2: There must be no rising transitions
Note 3: QSF = "L"-- Lower SAM (0 - 255) is active
QSF = "H"-- Upper SAM (256 - 511) is active
24/37
¡ Semiconductor
MSM548262
Masked Split Write Transfer
tRC
tRAS
tRP
RAS
tCSH
tRSH
tCAS
tRCD
CAS
tAR
tRAD
tRAH
tRAL
tASC
SAM Start Sj
tASR
Row
tCAH
Address
DSF
tFSR tRFH
tWSR tRWH
WE
tCTH
tATH
tMS
tMH
DQ1 - 8
TRG
Open
Mask Data
tRTH
tTLS
tTLH
tSTS
tSCC
tSCP
tSC
511
S i
254
255
(511)
Sj+256
(S j)
SC
(255)
(Si+256)
(510)
tSDS
tSDS
Data In
tSDH
tSDH
SDQ1 - 8
QSF
Data In
Data In
Data In
Data In
Data In
tSQD
Note 2
tSQD
Note 2
Note 2
"H" or "L"
Note 1: SE = "L"
Note 2: QSF = "L"-- Lower SAM (0 - 255) is active
QSF = "H"-- Upper SAM (256 - 511) is active
Note 3: Si is the SAM start address in before SWT
25/37
¡ Semiconductor
MSM548262
Serial Read Cycle
tSEP
SE
tSCC
tSC
SC
tSCA
tSCP
tSCA
tSOH
tSCA
tSOH
tSOH
tSEZ
tSEA
SDQ1 - 8
Data Out
Data
Data
Data Out
Data Out
Serial Write Cycle
tSEP
SE
tSWIS
tSCC
tSCP
tSWH
tSWIH
tSWS
tSC
SC
tSDS
Data In
tSDS
tSDH
tSZE
tSDH
SDQ1 - 8
Data In
Data In
Data In
"H" or "L"
26/37
¡ Semiconductor
MSM548262
PIN FUNCTIONS
Address Input: A0 - A8
The 18 address bits decode 8 bits of the 2,097,152 locations in the MSM548262 memory array. The
address bits are multiplexed to 9 address input pins (A0 - A8) as standard DRAM. 9 row address
bits are latched at the falling edge of RAS. The following 9 column address bits are latched at the
falling edge of CAS.
Row Address Strobe: RAS
RAS is a basic RAM control signal. The RAM port is in standby mode when the RAS level is
"high". As the standard DRAM’s RAS signal function, RAS is the control input that latches the
row address bits, and a random access cycle begins at the falling edge of RAS.
In addition to the conventional RAS signal function, the level of the input signals CAS, TRG, WE
and DSF at the falling edge of RAS, determines the MSM548262 operation mode.
Column Address Strobe: CAS
As the standard DRAM’s CAS signal function, CAS is the control input signal that latches the
column addressinputand thestateofthespecial function inputDSFtoselect in conjunction with
the RAS control, either read/write operations or the special block write feature on the RAM port
when the DSF is held "low" at the falling edge of RAS.
CAS also acts as a RAM port output enable signal.
Data Transfer/Output Enable: TRG
TRG is also a control input signal having multiple functions. As the standard DRAM’s OE signal
function, TRG is used as an output enable control when TRG is "high" at the falling edge of RAS.
In addition to the conventional OE signal function, a data transfer operation is started between
the RAM port and the SAM port when TRG is "low" at the falling edge of RAS.
Write Per Bit/Write Enable: WE
WE is a control input signal having multiple functions. As the standard DRAM’s WE signal
function, this is used to write data into the memory on the RAM port when WE is "high" at the
falling edge of RAS.
In addition to the conventional WE signal function, the WE determines the write-per-bit
function, when WE is "low" at the falling edge of RAS during RAM port operations.
The WE also determines the direction of data transfer between the RAM and SAM. When theWE
is "high" at the falling edge of RAS, the data is transferred from RAM to SAM (read transfer).
When the WE is "low" at the falling edge of RAS, the data is transferred SAM to RAM (write
transfer).
27/37
¡ Semiconductor
MSM548262
Write Mask Data/Data Input and Output: DQ1 - DQ8
In conventional write-per bit mode, the DQ pins function as mask data at the falling edge of RAS.
DataiswrittenonlytohighDQpins.DataonlowDQpinsismaskedandinternaldataisretained.
After that, they function as input/output pins similar to a standard DRAM.
Serial Clock: SC
SC is a main serial cycle control input signal. All operations of the SAM port are synchronized
with the serial clock SC. Data is shifted in or out of the SAM registers at the rising edge of SC. In
a serial read cycle, the output data becomes valid on the SDQ pins after the maximum specified
serial access time t
from the rising edge of SC.
SCA
In a serial write cycle, data on SDQ pins at the rising edge of SC are fetched into the SAM register.
Serial Enable: SE
The SE is a serial access enable control and serial read/write control signal. In a serial read cycle,
SE is used as an output control. In a serial write cycle, SE is used as a write enable control. When
SE is "high", serial access is disabled. However, the serial address pointer location is still
incremented when SC is clocked even when SE is "high".
Special Function Input: DSF
The DSF is latched at the falling edge of RAS and CAS. It allows for the selection of several RAM
portsandtransferoperatingmodes.InadditiontotheconventionalmultiportDRAM,thespecial
functions consisting of flash write, block write, load/read color register, and split read/write
transfer can be invoked.
Special Function Output: QSF
QSF is an output signal, which during split register mode indicates which half of the split SAM
is being accessed. QSF "low" indicates that the lower split SAM (0 - 255) is being accessed. QSF
"high" indicates that the upper SAM (256 - 511) is being accessed.
Serial Input/Output: SDQ1 - SDQ8
Serial input/output mode is determined by the most recent read or write transfer cycle. When
a read transfer cycle is performed, the SAM port is in the output mode. When a write transfer
cycle is performed, the SAM port is switched from output mode to input mode.
28/37
¡ Semiconductor
MSM548262
OPERATION MODES
Table-1 shows the function truth table for a listing of all available RAM ports, and transfer
operation of MSM548262.
The RAM port and data transfer operations are determined by the state of CAS, TRG, WE and
DSF at the falling edge of RAS, and by the level of DSF at the falling edge of CAS.
Table-1. Function Truth Table
CASØ
RASØ
Address
W/IO
Color
Register
Write
Mask
Code
CAS
Function
CAS TRG WE DSF DSF RASØ CASØ RASØ
/WEØ
CBR
ROR
MWT
MSWT
RT
0
1
1
1
1
1
1
1
1
1
1
1
*
1
0
0
0
0
1
1
1
1
1
1
*
*
0
0
1
1
0
0
0
1
1
1
*
0
0
1
0
1
0
0
1
0
0
1
—
—
*
*
*
*
*
*
—
*
—
—
—
—
CBR Refresh
Row
—
RAS Only Refresh
Row TAP WM1
Row TAP WM1
Yes
Yes
—
—
Masked Write Transfer
Masked Split
*
*
—
Write Transfer
*
Row TAP
Row TAP
*
*
*
—
Read Transfer
SRT
*
*
—
—
Split Read Transfer
Read/Write
(Mask)
RWM
BWM
FWM
RW
0
Row Column WM1 Din%Dout
Yes
Yes
Yes
No
—
Column
A2c - 8c
Column
Select
1
Row
Row
WM1
Use
Use
—
Masked Block Write
Masked Flash Write
*
*
WM1
—
Read/Write
(No Mask)
Block Write
(No Mask)
0
Row Column
*
*
*
Din%Dout
Column
Row
Column
Select
Color
Data
BW
1
No
—
Use
Load
A2c - 8c
LCR
1
Row
*
Load Color Register
If the DSF is "high" at the falling edge of RAS, special functions such as split transfer, flash write,
load color register can be invoked.
If the DSF is "low" at the falling edge of RAS and "high" at the falling edge of CAS, the block write
feature can be invoked.
29/37
¡ Semiconductor
MSM548262
RAM PORT OPERATION
RAM Read Cycle: RAS falling edge --- TRG = CAS = "H", DSF = "L"
CAS falling edge --- DSF = "L"
Row address is entered at the falling edge of RAS and column address at the falling edge of CAS
to the device as in conventional DRAM. When the WE is "high" and TRG is "low" while CAS is
"low", the data outputs through DQ pins.
RAM Write Cycle: RAS falling edge --- TRG = CAS = "H", DSF = "L"
CAS falling edge --- DSF = "L"
1) Write cycle with no mask: RAS falling edge -- WE = "H"
If WE is set "low" at the falling edge of CAS after RAS goes "low" a write cycle is excuted. If WE
is set "low" before the CAS falling edge, this cycle becomes an early write cycle, and all DQ pins
attain high impedance. All 8 data are latched on the falling edge of CAS.
If WE is set "low" after the CAS falling edge, this cycle becomes a late write cycle, and all 8 data
are latched on the falling edge of WE.
2) Write cycle with mask: RAS falling edge -- WE = "L"
If WE is set "low" at the falling edge of RAS, the mask write mode can be invoked.
Maskdataisloadedandused.ThemaskdataonDQ1-DQ8islatchedintothewritemaskregister
at the falling edge of RAS. When the mask data is low, writing is inhibited into the RAM and the
mask data is high, data is written into the RAM. This mask data is in effect during the RAS cycle.
In page mode cycle the mask data is retained during page access.
30/37
¡ Semiconductor
MSM548262
Load/Read Color Register: RAS falling edge --- CAS = TRG = WE = DSF = "H"
CAS falling edge --- DSF = "H"
The MSM548262 is provided with an on-chip 8-bit color register for use during the flash write or
block write operation. Each bit of the color register corresponds to one of the DRAM I/O blocks.
The data presented on the DQi lines is subsequently latched into the color register at the falling
edge of either CAS or WE whichever occurs later.
The read color register cycle is activated by holding WE "high" at the falling edge of CAS, and
throughout the remainder of the cycle. The data in the color register becomes valid on the DQi
lines after the specified access times from RAS and TRG are satisfied.
During the load/read color register cycle, the memory cells on the row address latched at the
falling edge of RAS are refreshed.
Flash Write: RAS falling edge --- CAS = TRG = DSF = "H", WE = "L"
Flash write allows for the data in the color register to be written into all the memory locations of
a selected row.
Each bit of the color register corresponds to one of the DRAM I/O blocks. The flash write
operation can be selectively controlled on an I/O basis in the same manner as the write per bit
operation. The mask data is the same as that of a RAM write cycle.
31/37
¡ Semiconductor
MSM548262
Block Write: RAS falling edge --- CAS = TRG = "H", DSF = "L"
CAS falling edge --- DSF = "H"
Block write allows for the data in the color register to be written into 4 consecutive column
address locations, starting from a selected column address in a selected row.
The block write operation can be selectively controlled on an I/O basis, and a column mask
capability is also available. During a block write cycle, the 2 least significant column address
locations (A0C and A1C) are internally controlled, and only the 7 most significant column
addresses (A2C - A8C) are latched at the falling edge of CAS.
1) No mask block write: WE "high" at the falling edge of RAS
The data on 8 DQ pins is all cleared by the data of the color register.
2) Masked block write: WE "low" at the falling edge of RAS
The mask data is the same as that of a RAM write cycle.
SAM PORT OPERATION
Single Register Mode
High speed serial read or write operation can be performed through the SAM port independent
of the RAM port operation, except during read/write transfer cycles.
The preceding transfer operation determines the direction of data flow through the SAM port.
If the preceding transfer is a read transfer, the SAM port is in the output mode. If the preceding
transfer is write transfer, the SAM port is in the input mode.
SerialdatacanbereadoutoftheSAMafterareadtransferhasbeenperformed.Thedataisshifted
out of the SAM starting at any of the 512 bits locations.
The TAP location corresponds to the column address selected at the falling edge of CAS during
the read or write transfer cycle. The SAM registers are configured as a circular data register. The
data is shifted out sequentially. It starts from the selected TAP location at the most significant bit
(511), then wraps around to the least significant bit (0).
Split Register Mode
In split register mode data can be shifted into or out of one half of the SAM, while a split read or
split write transfer is being performed on the other half of the SAM.
Conventional (non split) read, or write transfer cycle must precede any split read or split write
transfers. The split read and write transfers will not change the SAM port mode set by the
preceding conventional transfer operation. In the split register mode, serial data can be shifted
in or out of one of the split SAM registers, starting from any at the 256 TAP locations, excluding
the last address of each split SAM the data is shifted in or out sequentially starting from the
selected TAP location at the most significant bit (255 or 511) of the first split SAM, and then the
SAM pointer moves to the TAP location selected for the second split SAM to shift data in or out
sequentially, starts from this TAP location at the most significant bit (511 or 255), and finally
wraps around to the least significant bit.
TAP
TAP
0
1
2
255
256 257
511
32/37
¡ Semiconductor
MSM548262
DATA TRANSFER OPERATIONS
The MSM548262 features two types of bidirectional data transfer capability between RAM and
SAM.
1) Conventional(nonsplit)transfer:512wordsby8bitsofdatacanbeloadedfromRAMtoSAM
(Read transfer), or from SAM to RAM (Write transfer).
2) Splittransfer:256wordsby8bitsofdatacanbeloadedfromthelower/upperhalfoftheRAM
tothelower/upperhalfoftheSAM(Splitreadtransfer),orfromthelower/upperhalfofSAM
to the lower/upper half of RAM (Split write transfer).
The conventional transfer and split transfer modes are controlled by the DSF input signal.
Data transfer are invoked by holding the TRG signal "low" at the falling edge of RAS.
The MSM548262 supports 4 types of transfer operations: Read transfer, Split read transfer, Write
transfer and Split write transfer as shown in the truth table. The type of transfer operation is
determined by the state of CAS, WE and DSF latched at the falling edge of RAS. During
conventional transfer operations, the SAM port is switched from input to output mode (Read
transfer), or output to input mode (Write transfer). It remains unchanged during split transfer
operation (Split read transfer or Split write transfer).
Both RAM and SAM are divided by the most significant row address (AX8), as shown in Figure
1. Therefore, no data transfer between AX8 = 0 side RAM and AX8 = 1 side RAM can be provided
through the SAM. Care must be taken if the split read transfer on AX8 = 1 side (or AX8 = 0 side)
is provided after the read transfer or the split read transfer, is provided on AX8 = 0 side (or AX8
= 1 side).
256 ¥ 256 ¥ 8
Memory
256 ¥ 256 ¥ 8
Memory
Array
Array
256 ¥ 256 ¥ 8
Memory
256 ¥ 256 ¥ 8
Memory
Array
Array
AX8 = 0
AX8 = 1
SAM I/O Buffer
SDQ1 - 8
Figure 1. RAM and SAM Configuration
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MSM548262
Read Transfer: RAS falling edge --- CAS = WE = "H", TRG = DSF = "L"
Read transfer consists of loading a selected row of data from the RAM into the SAM register. A
read transfer is invoked by holding CAS "high", TRG "low", WE "high", and DSF "low" at the
fallingedgeofRAS. TherowaddressselectedatthefallingedgeofRASdeterminestheRAMrow
to be transferred into the SAM. The transfer cycle is completed at the rising edge of TRG. When
the transfer is completed, the SAM port is set into the output mode. In a read/real time read
transfer cycle, the transfer of a new row of data is completed at the rising edge of TRG, and this
data becomes valid on the SDQ lines after the specified access time t
from the rising edge of
SCA
the subsequent SC cycles. The start address of the serial pointer of the SAM is determined by the
column address selected at the falling edge of CAS. In a read transfer cycle (which is preceded
by a write transfer cycle), SC clock must be held at a constant V or V after the SC high time
IL
IH
has been satisfied. A rising edge of the SC clock must not occur until after the specified delay t
TSD
from the rising edge of TRG.
In a real time read transfer cycle (which is preceded by another read transfer cycle), the previous
row data appears on the SQD lines until the TRG signal goes "high", and the serial access time
t
for the following serial clock is satisfied. This feature allows for the first bit of the new row
SCA
of data to appear on the serial output as soon as the last bit of the previous row has been strobed
withoutanytimingloss. Tomakethiscontinuousdataflowpossible, therisingedgeofTRGmust
besynchronizedwithRAS, CAS, andthesubsequentrisingedgeofSC(t
, t
, andt /t
RTH CTH TSL TSD
must be satisfied).
Masked Write Transfer: RAS falling edge --- CAS = "H", TRG = WE = DSF = "L"
Write transfer cycle consists of loading the content of the SAM register into a selected row of the
RAM. This write transfer is the same as a mask write operation in RAM.
If the SAM data to be transferred must first be loaded through the SAM, a Masked write transfer
operation (all DQ pins "low" at falling edge of RAS) must precede the write transfer cycles. A
masked write transfer is invoked by holding CAS "high", TRG "low", WE "low" and DSF "low"
at the falling edge of RAS. The row address selected at the falling edge of RAS determines the
RAM row address into which the data will be transferred. The column address selected at the
falling edge of CAS determines the start address of the serial pointer of the SAM. After the write
transfer is completed, the SDQ lines are set in the input mode so that serial data synchronized
with the SC clock can be loaded.
When consecutive write transfer operations are performed, new data must not be written into
the serial register until the RAScycle of the preceding write transfer is completed. Consequently,
the SC clock must be held at a constant V or V during the RAS cycle. A rising edge of the SC
IL
IH
clockisonlyallowedafterthespecifieddelayt
a new row of data can be written in the serial register.
fromthefallingedgeoftheCAS, atwhichtime
CSD
Data transferred to SAM by read transfer cycle or split read transfer cycle can be written to the
other address of RAM by write transfer cycle. However, the address to write data must be the
same as that of the read transfer cycle (row address AX8).
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¡ Semiconductor
MSM548262
Split Data Transfer and QSF
The MSM548262 features a bidirectional split data transfer capability between the RAM and
SAM. During split data transfer operation, the serial register is split into two halves which can
be controlled independently. Split read or split write transfer operation can be performed to or
from one half of the serial register, while serial data can be shifted into or out of the other half of
the serial register. The most significant column address location (A8C) is controlled internally to
determines which half of the serial register will be reloaded from the RAM. QSF is an output
which indicates which half of the serial register is in an active state. QSF changes state when the
last SC clock is applied to active split SAM.
Split Read Transfer: RAS falling edge --- CAS = WE = DSF = "H", TRG = "L"
Split read transfer consists of loading 256 words by 8 bits of data from a selected row of the split
RAM into the corresponding non-active split SAM register. Serial data can be shifted out from
the other half of the split SAM register simultaneously. During split read transfer operation, the
RAM port input clocks do not have to be synchronized with the serial clock SC, thus eliminating
timingrestrictionsasinthecaseofrealtimereadtransfers. Asplitreadtransfercanbeperformed
after a delay of t
from the change of state of the QSF output is satisfied.
STS
Conventional (non-split) read transfer operation must precede split read transfer cycles.
Masked Split Write Transfer: RAS falling edge --- CAS = DSF = "H", TRG = WE ="L"
Split write transfer consists of loading 256 words by 8 bits of data from the non-active split SAM
register into a selected row of the corresponding split RAM. Serial data can be shifted into the
other half of the split SAM register simultaneously. During split write transfer operation, the
RAM port input clocks do not have to be synchronized with the serial clock SC, thus allowing
for real time transfer. This write transfer operation, which is the same as a mask write operation
in RAM, can be selectively controlled for 8 DQis by inputing the mask data from DQ1 - DQ8 at
the falling edge of RAS.
A split write transfer can be performed after a delay of t
output is satisfied.
from the change of state of the QSF
STS
A masked write transfer operation must precede split write transfer. The purpose is to switch the
SAM port from output mode to input mode, and to set the initial TAP location prior to split write
transfer operations.
POWER UP
Power must be applied to the RAS and TRG input signals to pull them "high" before, or at the
same time as, the V supply is turned on. After power-up, a pause of 200 ms minimum is
CC
required with RAS and TRG held "high". After the pause, a minimum of 8 RAS and 8 SC dummy
cycles must be performed to stabilize the internal circuitry, before valid read, write or transfer
operations can begin. During the initialization period, the TRG signal must be held "high". If the
internal refresh counter is used, a minimum 8 CAS before RAS cycles are required instead of 8
RAS cycles.
(NOTE) INITIAL STATE AFTER POWER UP
The initial state can not be guaranteed for various power up conditions and input signal levels.
Therefore, it is recommended that the initial state be set after the initialization of the device is
performed and before valid operations begin.
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¡ Semiconductor
PACKAGE DIMENSIONS
SOJ40-P-400-1.27
MSM548262
(Unit : mm)
Mirror finish
Package material
Lead frame material
Pin treatment
Solder plate thickness
Package weight (g)
Epoxy resin
42 alloy
Solder plating
5 mm or more
1.70 TYP.
Notes for Mounting the Surface Mount Type Package
The SOP, QFP, TSOP, SOJ, QFJ (PLCC), SHP and BGA are surface mount type packages, which
are very susceptible to heat in reflow mounting and humidity absorbed in storage.
Therefore, before you perform reflow mounting, contact Oki’s responsible sales person for the
product name, package name, pin number, package code and desired mounting conditions
(reflow method, temperature and times).
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¡ Semiconductor
MSM548262
(Unit : mm)
TSOPII44/40-P-400-0.80-K
Mirror finish
Package material
Lead frame material
Pin treatment
Solder plate thickness
Package weight (g)
Epoxy resin
42 alloy
Solder plating
5 mm or more
0.49 TYP.
Notes for Mounting the Surface Mount Type Package
The SOP, QFP, TSOP, SOJ, QFJ (PLCC), SHP and BGA are surface mount type packages, which
are very susceptible to heat in reflow mounting and humidity absorbed in storage.
Therefore, before you perform reflow mounting, contact Oki’s responsible sales person for the
product name, package name, pin number, package code and desired mounting conditions
(reflow method, temperature and times).
37/37
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