D6455A-11 [ETC]
Telecommunication IC ; 电信IC\n
| 型号： | D6455A-11 |
| 厂家： | 
ETC |
| 描述： | Telecommunication IC
|
| 文件： | 总4页 (文件大小：385K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
D6455A/B
EASYTAD Chip for an all Digital Telephone Answering Device with
Super Low Rate Coder and True FULL Duplex SpeakerPhone
General Description
The D6455A/B chip is a digital speech/signal processing subsystem that implements all functions of TRUESPEECH
speech compression and voice prompts, telephone line signal processing, flash memory management and True FULL
Duplex SpeakerPhone for an all digital answering machine. The D6455A/B is fully controlled by the system Host
through a simple interface protocol. The Host controller provides activation and control of all system functions such as
speech recording and playback, DTMF and call progress tone detection, DTMF and tone generation, and voice
prompting.
Host
Controller
Telephone
Phone
Line
Line
Interface
CODEC
Voice
Prompt
ROM
A
D6455A/B
DSP Speech
Processor
Speaker
Phone
Interface
CODEC
ARAM
Optional
Figure 1. D6455A/B System Block Diagram
Key Features
n High-quality, new super low rate TRUESPEECH
digital speech compression allowing 25-27 minutes
of recording time per each 4 Mbit of memory
n Works with 256Kx4 (1 Mbit)*, 1Mx4 (4 Mbit) or
4Mx4 (16 Mbit)* ARAMs
n True FULL Duplex SpeakerPhone with both
acoustical and near-end echo cancellation
n Flexible storage of incoming messages (ICM),
outgoing messages (OGM). Supports multiple
OGMs and multiple mailboxes
n Programmable Thresholds for VOX, DTMF, and
Call Progress
n TRUESPEECH, natural-sound voice prompting, for
Day/Time stamp and voice instructions
n Digital Volume Control
n Supports offset playback for jumps within a
message
n DTMF generation and detection with near-end
echo cancellation for superior performance
n Low power consumption
n Simple 8-bit Host Interface
n Special commands for production line testing
n Fully compatible with the D6305B. Host software
compatible, pin-for-pin replaceable
* Supported in D6455B only
D6455A/B
AA
Device Configuration and System Components
n D6455A/B-11 Digital Telephone Answering Device (TAD) processor
(80-pin PQFP) 1 each
STANDARD COMPONENTS
These are supplied by the customer according to DSP Groups specifications.
n D0000-29 Analog I/O Interface (16-pin DIP) 1 each, 2 for SpeakerPhone
One of the following:
ADDITIONAL SYSTEM COMPONENTS
n D0000-37C 1-Mbit ARAM Message Memory (SOJ) Up to four devices
per system (D6455B only)
n D0000-36C 16-Mbit ARAM Message Memory (SOJ) Up to two devices
per system (D6455B only), or
n D0000-35C 4-Mbit ARAM Message Memory (SOJ) Up to four devices per
system
EPROM/ROM - For Voice Prompt storage an external EPROM/ROM (access
time, 300 ms or less) is required -each 32K x 8 block supports 65 seconds of
Voice Prompt (up to 64K).
OPTIONAL SYSTEM COMPONENTS
A
Top View
D6455A-11
PDN
Figure 2. D6455A/B Pin Diagram
D6455A/B
AA
System Functions
All of the speech processing tasks are done by the DSP Speech Subsystem. This allows the use of a very low cost
microcontroller to be used for basic control of the system. The Host need only send high level commands to perform
functions such as Record Message or Delete Message and the operation will be performed by the DSP subsystem which
will report the status of the operation to the Host. All memory interface and management will be taken care of by the
DSP requiring the Host to only handle high level system functions. A summary of the functions performed by the DSP
Speech Subsystem and Host Controller are shown in Figure 3, below.
DSP Speech Subsystem
n Speech Recording
n Speech Playback
Host Controller
n Memory / Message Management
n DTMF and Tone Genertion
n Control the System
n DTMF Detection
n Read Buttons
n Call Process Detection
n Control Displays / Switches
n Time / Date Stamping
n Voice Prompts
n Phone Number Storage
n SpeakerPhone Functions
Figure 3. System Functions
Simple Hardware Interface
The hardware interface between the D6455A/B and the Host Controller is a simple one requiring only an 8 bit parallel
port and 4 handshake lines. The Host writes high level Commands to the D6455A/B and the D6455A/B will respond
with Status information. Once a Command is issued the D6455A/B will use the ACK pin to indicate that the Status is
available to be read. The hardware interface between the D6455A/B and Host is shown in Figure 4 below.
8051
D6455A/B-11
8
Port 0
HSTD0-7
RD
WR
HSTR
HSTW
HI/LO
ACK
HI/LO
INT
Figure 4. D6455A/B / Host Interface
Benefits of the D6455A/B
n New Super Low Rate TRUESPEECH digital speech
compression allowing 25-27 minutes of recording
time in only 4 Mbits of memory. This reduces the
memory requirement or makes more recording time
available in your design
n TRUESPEECH natural sounding voice prompts and
time/date stamping allow design of a high quality
and professional sounding product
n The True Full-Duplex SpeakerPhone capability
allow a very professional sounding SpeakerPhone to
be added to your product with a very minimal
additional cost
n Allows flexibility in design for features such as
multiple mailboxes and multiple OGMs allowing
design of a product that is truly a Personal Voice
Mail System
n Flexibility of memory configuration, in the
D6455A, allows the use of most readily available
and cost effective memory
n The Host selectable thresholds for VOX, DTMF,
and Call Progress allows for flexibility in design for
various countries and different applications
TRUESPEECH is a registered trademark, and True FULL Duplex SpeakerPhone are trademarks of DSP Group, Inc. Other company and product names mentioned
in this document may be the trademark or registered trademark of their respective manufacturers.
PO-1/96
Printed in USA
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