
2-4
2—SOFTWARE
ISD-SR3000
Voice Solutions in Silicon
2.2.5
ADDITIONAL COMPONENTS
MESSAGE
A message is a compressed recording stored in the ISD-SR3000 memory. This message can
be compressed, when using the R (Record Message) command, at 4.7, 6.7 or 8.7kbits/s.
NOISE TOKENS
Each topic can be supplemented with additional tokens that will absorb the ‘out of vocabulary’
words. These tokens can be added upon user request with ISD’s development tools. These to-
kens are not assigned an index number like the other words in the topic table. Once the engine
recognizes a word as a noise token, the ISD-SR3000 returns the noise topic identifier (0xFD)
instead of the current topic.
CEPSTRA VALUES
The cepstra coefficients are responsible for normalizing the voice input channel. The ISD-
SR3000 contains 15 cepstra values starting from index 0.
VOICE TAG
A voice tag is a recorded message of a user-added word. This message can be compressed,
when using the RR (Record for Reco) command, at 4.7, 6.7 or 8.7kbits/s.
2.3
After the system is powered up, it is the host controller’s responsibility to initialize the ISD-
SR3000. This initialization includes: resetting the chip using the RESET signal, configuring the
hardware environment using the CFG command (CODEC and memory types and parameters,
etc.), and issuing the INIT and TUNE commands. The TUNE and CFG commands are required
only if the system settings are different from the ISD-SR3000’s default values.
INITIALIZATION
Refer to the section ISD-SR3000 Initialization on
page 2-68
for an example illustrating the sys-
tem initialization procedure for the ISD-SR3000.
2.4
After the system has been initialized (including setting the vocabulary for the prompts) it is the
host controller’s responsibility to initialize the recognition engine. This includes loading of top-
ics, enabling topics and activating the recognition engine. It is recommended that you load all
the topics if the system memory size enables it, rather then loading and unloading a topic each
time one needs to be enabled.
RECO ENGINE MANAGEMENT