D6571E Data Sheet
A
D6571E
EASYTAD™ Chip for an All-Digital
Telephone Answering Machine
with Flash Memory Interface
GENERAL DESCRIPTION
The D6571E 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 D6571E is fully controlled by the system HOST through a
simple interface protocol. The HOST processor 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.
The fully digital solution has no moving parts, yielding high reliability. The chip’s programmability enables a full range of
answering, recording and playback features for the end user. The D6571E is a single-chip, digital signal processor that
includes all of the necessary circuitry to interface with an external HOST, flash memory, and codec.
FEATURES
• Superior quality TRUESPEECH® Triple Rate Codertm
allowing selectable 11, 15 or 25 minutes of recording
time per each 4 Mbit Flash Memory
• PCM Recording
• Flexible storage of incoming messages (ICM),
outgoing messages (OGM). Supports multiple OGMs
and multiple mailboxes.
• TRUESPEECH®, natural-sound voice prompting, for
Day/Time stamp and voice instructions
• FLEXISPEECH™ variable speed, natural sound
playback (50% - 200%)
• DTMF generation and detection with near-end echo
cancellation for superior performance
• Extended DTMF detection (A, B, C, D)
• Automatic Gain Control
• True FULL Duplex SpeakerPhone™ with both
acoustical and near-end echo cancellation
• Caller ID and Call Waiting CID demodulation (both
Bell 202 and V.23)
• FSK modem for CID andα-5 support
• Supports 4 Mb or 16 Mb Flash Memory Devices
• Supports Time Stamp (message tag) modification
• Programmable DTMF, CPT, VOX, CAS, and FSK
Detectors Sensitivity
• Digital Volume Control
• µ-law and A-law codec support, selectable Master
and Slave mode, selectable sampling rate.
• General Purpose (CID) and Non-Erasable Storages
MIC
SPEAKER
TEL
LINE
SpeakerPhone
Codec
Codec
I/O Codec
HOST
Controlle
r
D6571E
DSP
Speech
Processor
Voice
Prompt
ROM **
16 Mbit
Flash
OR
4 Mbit
Flash
Voice Prompt
*
4 . . 16
Figure 1. D6571E Block Diagram
* Dashed lines indicate optional implementation
** Only supported with single 4Mbit Flash or no
All specifications are subject to change without prior notice
DS6571E.2
DSP GROUP, INC., 3120 SCOTT BOULEVARD
5
SANTA CLARA, CA 95054 PH: 408 986-4300 FAX: 408 986-4490