NSAM266SA Datasheet, PDF (32/52 Pages) National Semiconductor (TI) – NSAM266SA CompactSPEECHTM Digital Speech Processor with Serial Flash Interface

2 0 Software (Continued)
FIGURE 2-6 Master MICROWIRE Data Transfer
TL EE 12584 – 30
2 14 COMMAND DESCRIPTION
The commands are listed in alphabetical order
The execution time for all commands when specified in-
cludes the time required for the microcontroller to retrieve
the return value where appropriate
The execution time does not include the protocol timing
overhead i e the execution times are measured from the
moment that the command is detected as valid until the
command is fully executed
Note Each command description includes an example application of the
command The examples show the opcode issued by the microcon-
troller and the response returned by the CompactSPEECH For com-
mands which require a return value from the CompactSPEECH the
start of the return value is indicated by a thick vertical line
CCIO
Configure Codec I O config-value
Configures the voice samples paths in various states It
should be used to change the default CompactSPEECH
configuration The config-value parameter is encoded as
follows
Bit 0
Loopback control
0 Loopback disable (default)
1 Loopback enabled During RECORD state
the input samples are echoed back un-
changed (i e no volume control) to the co-
dec
Bits 1 – 7 Reserved
Example
CCIO 3401
Microcontroller 34 01
Byte sequence
CompactSPEECH 34 01
Description Enable Loopback
CFG
Configure CompactSPEECH config value
Configures the CompactSPEECH in various hardware envi-
ronments It should be used to change the default Compact-
SPEECH configuration
The config value parameter is encoded as follows
Bit 0
Codec configuration
0 short-frame format (default)
1 long-frame format (Guaranteed by design
but not tested )
Bit 1
Reserved
Bit 2
Echo cancellation control
0 Echo cancellation off (default)
1 Echo cancellation is on during playback
Echo cancellation improves the performance of
DTMF detection during playback Echo cancel-
lation can be turned on only with a system that
can disable AGC during playback A system
with AGC that cannot be controlled (i e en-
abled disabled) by the microcontroller must not
turn on this bit
Bit 3
Reserved must be cleared to 0
Bits 4 – 5 Reserved must be set to 10
Bits 6 – 7 Reserved must be cleared to 00
Bits 8 – 10 Number of installed flash devices
Valid range 1 4 flash devices
Default is 1
Bits 11 – 15 Reserved Must be cleared to 0
Note The CompactSPEECH automatically detects the type of flash device
in use i e NM29A040 or NM29A080
Example
CFG 0324
Microcontroller 01 03 24
Byte sequence
CompactSPEECH 01 03 24
Description
Configure the CompactSPEECH to work
with
Codec that supports short-frame format
Three NM29A040 flash devices
Echo cancellation on
CMT
Cut Message Tail time length
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 g0 14 sec
Note If time length is longer than the total duration of the message the
EV NORMAL END event is set in the status word and the mes-
sage becomes empty (i e message length is 0) but is not deleted
Use the DM (Delete Message) or DMS (Delete Messages) command
to delete the message
Example
CMT 02BC
Microcontroller 26 02 BC
Byte sequence
CompactSPEECH 26 02 BC
Description
Cut the last seven seconds of the current
message
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