D6305B
A
EASYTADä Chip for an All- Digital
Telephone Answering Machine
The D6305B chip is a digital speech/signal processing
subsystem that implements all of the functions of speech
compression, telephone line signal processing, memory
management, and TRUESPEECHâ natural sounding
voice prompting for an all digital answering machine.
The D6305B 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 tone
generation, DTMF and call progress tone detection, and
voice prompting.
VOICE
PROMPT
ROM
Analog I/O
16M
ARAM
D6305B
OR
HOST
controller
4M
ARAM
The fully digital solution has no moving parts, yielding
high reliability. The chip’s programmability enables a
full range of answering device features for the end user.
The D6305B is a single-chip, digital signal processor
that includes all of the necessary circuitry to interface
with an external HOST, memory, and an analog front
end.
Figure 1. D6305B Block Diagram
FEATURES
·
High-quality, variable low rate TRUESPEECHâ
digital speech compression allowing 14-15 minutes
of recording time per each 4 MB ARAM (Audio
grade DRAM)
·
·
·
·
Uses more relaxed ARAM specifications (standard
ARAM)
Will work with 1M x 4 (4MB) or 4M x 4 (16 MB)
ARAMs
·
Flexible storage of incoming messages (ICM) and
outgoing messages (OGM). Supports multiple
OGMs and multiple mailboxes
Supports “offset playback” for jumps within a
message
Programmable Tone Generation and Tone
Generation from tables
·
·
·
TRUESPEECHâ natural-sound voice prompting,
for Day/Time stamp and voice instructions
·
·
·
·
8-bit parallel HOST interface
DTMF generation and detection with near-end echo
cancellation for superior performance
Storage of 32 telephone numbers for speed dialing
Low power consumption
Fully backwards compatible with D6305A. Host
software compatible, pin-to-pin replaceable
Special commands for production line testing
6050302.2
DSP GROUP, INC., 3120 SCOTT BLVD.,
SANTA CLARA, CA 95054 PH: 408-986-4300 FAX: 408-986-4323