ISD-T360SB Datasheet, PDF (43/109 Pages) List of Unclassifed Manufacturers – VoiceDSP Digital Speech Processor with Master/Slave, Full-Duplex Speakerphone, Multiple Flash and ARAM/DRAM Support

2—SOFTWARE
ISD-T360SB
2.1.4 MESSAGE HANDLING
A message is the basic unit on which most of the
VoiceDSP commands operate. A VoiceDSP pro-
cessor message, stored on a memory device
(Flash or ARAM/DRAM), can be regarded as a
computer file stored on a mass-storage device.
The ISD-T360SB manages messages for a wide
range of applications, which require different
levels of DTAD functionality. The VoiceDSP pro-
cessor features advanced memory-organization
features such as multiple OutGoing Messages
(OGMs), mailboxes, and the ability to distinguish
between InComing Messages (ICMs) and
OGMs.
A message is created with either the R (Record)
or the CMSG (Create Message) command.
Once created, the message is assigned a time-
and-day stamp and a message tag which is
read by the microcontroller. The R command
takes voice samples from the codec, compress-
es them, and stores them in the message mem-
ory.
When a message is created with the CMSG
command the data to be recorded is provided
by the microcontroller, via the WMSG (Write Mes-
sage) command and not through the codec.
Here, the data is transferred directly to the mes-
sage memory, and not compressed by the ISD-
T360SB voice compression algorithm.
WMSG, RMSG (Read Message) and SMSG (Set
Message Pointer) are message-data access
commands used to store and read data to or
from any location in the message memory (see
“VoiceDSP PROCESSOR COMMANDS—QUICK
REFERENCE TABLE” on page 2-21 for more de-
tails). Using these commands, the microcontrol-
ler utilizes messages for features such as a
Telephone Directory and playing back (P com-
mand) or deleting (DM command) a message.
Remove redundant data (e.g., trailing tones or
silence) from the message tail with the CMT (Cut
Message Tail) command.
The PA (Pause) and RES (Resume) commands
suspend the P and R commands, respectively,
and then resume them from where they were
suspended.
CURRENT MESSAGE
The GTM (Get Tagged Message) command se-
lects the current message. Most message han-
dling commands (P, DM, RMSG), operate on the
current message.
Deleting the prevailing message does not cause
a different message to become current; the cur-
rent message is undefined. If you issue the GTM
command to skip to the next message, the first
message, newer than the just deleted message,
becomes the current message.
MESSAGE TAG
Each message has a 2-byte message tag which
used to categorize messages, and implement
such features as OutGoing Messages, mailbox-
es, and different handling of old and new mes-
sages.
The tag is created during the R (Record) com-
mand. Use the GMT (Get Message Tag) and SMT
(Set Message Tag) commands to handle mes-
sage tags.
NOTE
Message tag bits can only be cleared and
are set only when a message is first cre-
ated. This limitation, inherent in Flash
memories, allows bits to be changed only
from 1 to 0 (changing bits from 0 to 1
requires a special erasure procedure).
However, the usual reason for updating an
existing tag is to mark a message as old. This
can be done when a message is first cre-
ated by using one of the bits as a new/old
indicator, setting the bit to 1 and later
clearing it when necessary.
ISD
2-3