ISD-T360 ETC [List of Unclassifed Manufacturers], ISD-T360 Datasheet - Page 42

• 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]

2.1.2
A VoiceDSP processor command is represented
by an 8-bit opcode. Some commands have pa-
rameters and some have return values. Com-
mands are either synchronous or asynchronous.
SYNCHRONOUS COMMANDS
A synchronous command must complete exe-
cution before the microcontroller can send a
new command (e.g. GMS, GEW). A command
sequence begins when the microcontroller
sends an 8-bit opcode to the processor, fol-
lowed by the command’s parameters (if any).
The VoiceDSP processor then executes the com-
mand and, if required, transmits a return value to
the microcontroller. Upon completion, the pro-
cessor notifies the microcontroller that it is ready
to accept a new command.
ASYNCHRONOUS COMMANDS
An asynchronous command starts execution in
the background and notifies the microcontroller,
which can send more commands while the cur-
rent command is still running (e.g. R, P). After re-
ceiving an asynchronous command, such as P
(Playback), R (Record), SW (Say Words) or GT
(Generate Tone), the VoiceDSP processor
switches to the appropriate state and executes
the command until finished or a S (Stop) or PA
(Pause) command is received from the micro-
controller. When completed, the EV_NORMAL
_END event is set and the processor switches to
the IDLE state.
“VoiceDSP PROCESSOR COMMANDS—QUICK
REFERENCE TABLE” on page 2–21 displays all the
processor commands, the valid source states in
which these commands are valid, and the states
resulting from the command.
2-2
COMMAND EXECUTION
2.1.3
STATUS WORD
The 16-bit status word indicates events that oc-
cur during normal operation. The VoiceDSP pro-
cessor activates the MWRQST signal, to indicate
a change in the status word. This signal remains
active until the processor receives a GSW (Get
Status Word) command.
For detailed description of the Status Word and
the meaning of each bit, see “GSW Get Status
Word” on page 2-33.
ERROR WORD
The 16-bit error word indicates errors that oc-
curred during execution of the last command. If
an error is detected, the command is not pro-
cessed; the EV_ERROR bit in the status word is set
to 1, and the MWRQST signal is activated.
ERROR HANDLING
When the microcontroller detects the active
MWRQST signal, it issues the GSW command, de-
activating the MWRQST signal. Then, the micro-
controller tests the EV_ERROR bit in the status
word, and, if set, sends the GEW (Get Error Word)
command to read the error word for details.
For detailed description of the Error Word and
the meaning of each bit, see “GEW Get Error
Word” on page 2-30.
EVENT HANDLING
Voice Solutions in Silicon
2—SOFTWARE
™