ISD-T360 ETC [List of Unclassifed Manufacturers], ISD-T360 Datasheet - Page 41

• Manufacturer Part Number: ISD-T360
• Description: VoiceDSP Digital Speech Processor with Master/Slave, Full-Duplex Speakerphone, Multiple Flash and ARAM/DRAM Support
• Manufacturer: ETC [List of Unclassifed Manufacturers]

2—SOFTWARE
Chapter 2ÑSOFTWARE
The VoiceDSP software resides in the on-chip
ROM. It includes DSP-based algorithms, system
support functions and a software interface to
hardware peripherals.
2.1
This section provides details of the system sup-
port functions and their principle operation. It is
divided into the following subjects:
• The State Machine
• Command Execution
• Event Handling
• Message Handling
• Tone Generation
• Initialization and Configuration
• Power Down Mode (PDM)
2.1.1
The ISD-T360SB operates in two modes, normal
mode (DTAD) and speakerphone mode. To
change the mode use the Set Speakerphone
Mode (SSM) command. The VoiceDSP processor
functions as a state machine under each mode.
It changes state either in response to a com-
mand sent by the microcontroller, after execu-
tion of the command is completed, or as a result
of an internal event (e.g. memory full or power
failure). For more information see “VoiceDSP
PROCESSOR COMMANDS—QUICK REFERENCE
TABLE” on page 2-21. The VoiceDSP states are
desctibed below:
RESET
The VoiceDSP processor is initialized to the RESET
state after a full hardware reset by the RESET sig-
nal (See “RESETTING” on page 1-3). In this state
ISD
SYSTEM OPERATION
THE STATE MACHINE
the processor detectors (VOX, constant energy,
call progress tones and DTMF) are not active. In
all other states, these detectors are active. (See
the SDET and RDET commands for further de-
tails).
IDLE
This is the state from which most commands are
executed. As soon as a command and all its pa-
rameters are received, the processor starts exe-
cuting the command.
PLAY
In this state a message is decompressed (unless
stored in PCM format), and played back.
RECORD
In this state a message is compressed (unless
stored in PCM format) and recorded into the
message memory.
SYNTHESIS
An individual word or a sentence is synthesized
from an external vocabulary in this state.
TONE_GENERATE
In the TONE_GENERATE state, the VoiceDSP pro-
cessor generates single or DTMF tones.
MSG_OPEN
The VoiceDSP processor either reads or writes 32
bytes to the message memory, or sets the mes-
sage read/write pointer on a 32 byte boundary.
2-1