NSAM265SR Datasheet, PDF (23/58 Pages) National Semiconductor (TI) – CompactSPEECH Digital Speech Processors

3 0 Command Set (Continued)
CMT
Cut Message Tail time length
NSAM265SR
NSAM265SF
Cut time length units each of 10 ms duration off the end
of the current message The maximum value of time
length is 6550 Cut-time accuracy is 0 14 seconds
Note If time length is longer than or equal to the total duration of the
message the EV NORMAL END event is set in the status word
and the message becomes empty (i e message length is 0) but is
not deleted Use the DM (Delete Message) or DMS (Delete Mes-
sages) command to delete the message
CVOC
Check Vocabulary
NSAM265SR
NSAM265SF
Checks the correctness of the current selected vocabulary
The purpose of this command is to check the correctness of
IVS vocabularies which were pre-programmed to a FLASH
device
If the vocabulary data is OK or if the current vocabulary is
the internal vocabulary the return value is 1 Otherwise the
return value is 0
DM
Delete Message
NSAM265SR
NSAM265SF
Deletes the current message Deleting a message clears its
message tag
Deleting the current message does not cause a different
message to become current The current message is unde-
fined If for example you issue the GTM command to skip
to the next message the first message that is newer than
the just deleted message will be selected as the current
message
NSAM265SR
The memory space released by the deleted message is im-
mediately available for recording new messages
NSAM265SF
The memory space released by the deleted message is po-
tentially available (see the GMS command) but in practice
is available only after the FR command has been executed
DMS
Delete Messages tag ref tag mask
NSAM265SR
NSAM265SF
Deletes all messages whose message tags match the tag
ref parameter Only bits set in tag mask are compared i e
a match is considered successful if
message tag and tag mask e tag ref and tag mask
where and is a bitwise AND operation
After the command completes execution the current mes-
sage is undefined Use the GTM to select a different mes-
sage to be the current message
NSAM265SR
The memory space released by the deleted message is im-
mediately available for recording new messages
NSAM265SF
The memory space released by the deleted message is po-
tentially available (see the GMS command) but in practice
is available only after the FR command has been executed
FR
Free Memory
NSAM265SRV
NSAM265SF
Frees memory space for recording When a message is de-
leted with a DM or DMS command the memory space
which was occupied by the deleted message is marked DE-
LETED but is not available for recording new messages
The process performed by the FR command makes this
memory space available for recording
When execution of the FR command starts the state of the
CompactSPEECH changes to MEMORY FREE When the
process is completed the CompactSPEECH sets the EV
NORMAL END event and activates the MWRQST signal
The process can be stopped with the S command The typi-
cal execution time of an S command following an FR com-
mand is 1 second Since the process involves erasure of
AFLASH blocks the maximum execution time of an S com-
mand following an FR command is according to the
AFLASH device specification (i e 3 seconds a single
block erasure time)
Possible schemes for using FR in a DAM environment
 When the CompactSPEECH is idle for a few seconds
after a sequence of one or more DM or DMS commands
A typical DAM session involves listening to ICMs and
deleting some of them The microcontroller assumes that
such a session has been completed if the Compact-
SPEECH is idle for a preset time and should then issue
the FR command
 During initialization (after the INIT command has been
executed) We recommend sending a GMS command to
see if there is sufficient potential additional recording
time to justify sending the FR command
We recommend suspending FR execution (with the S com-
mand) if a ring is detected to minimize the time taken by the
CompactSPEECH to prepare for ICM recording
Note After FR execution has been completed the current message is un-
defined Use the GTM command to select the current message
GCFG
Get Configuration Value
NSAM265SR
NSAM265SF
This command returns a sequence of two bytes with the
following information
Bits 0 – 7
Magic number which specifies the Compact-
SPEECH firmware version
Bits 8 – 9 Memory type
00 ARAM
01 AFLASH
10 11 Reserved
The command should be used together with the CFG and
INIT commands during CompactSPEECH initialization See
the CFG command for more details and an example of a
typical initialization sequence
GEW
Get Error Word
NSAM265SR
NSAM265SF
Returns the 2-byte error word
The Error Word
The 16-bit error word indicates errors that occurred during
execution of the last command If an error is detected the
command is not processed the EV ERROR bit in the
status word is set to 1 and the MWRQST signal is activated
(set to low)
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