Texas Instruments MSP53C691, Руководство пользователя

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Description of the Command Codes
3-32
3.5.7 Command Header 7—Return Buffer Status
The MSP53C691 can be queried to return the status of the CELP/MELP or FM
buffer at anytime while speaking. The MSP53C691 returns four nibbles
representing the number of empty bytes in the buffer. The sequence of events
for returning the status of a buffer is as follows:
1) The MSP53C691 pulls INRDY low, requesting command or speech data.
2) The master sends the command header 0x7 as follows:
DATA LINES
DATA4 DATA3 DATA2 DATA1 DATA0
0 0 1 1 1
3) After the command header is received and latched into the MSP53C691,
the MSP53C691 pulls INRDY low again, requesting the level 1 command.
4) The master can send the level 1 command 1 (if requesting CELP/MELP
buffer status) or 2 (if requesting FM buffer status).
DATA LINES
DATA4 DATA3 DATA2 DATA1 DATA0
0 0 0 X X
5) In return, the MSP53C691 pulls OUTRDY low to send a nibble back to the
master. The master reads the nibble from the MSP53C691. The
MSP53C691 pulls OUTRDY low again sending a total of four nibbles: 0,
0, X
1,
and X
2.
X
1
X
2
represent the number of empty bytes in the buffer in
hexadecimal format.
3.5.8 Command Header 8—Initiate Sleep
The MSP53C691 can be put into sleep mode when it is not speaking or even
during speaking. The MSP53C691 can be put into three levels of sleep modes:
light, mid, and deep. For details about the specification for the three different
sleep modes, consult the data sheet listed in Table 2–9 of the SPSU014
manual. The sequence of events in sleep mode is as follows:
1) The MSP53C691 pulls INRDY low requesting for command or more
speech data.
2) The master sends the command header 0x8 to the MSP53C691.
DATA LINES
DATA4 DATA3 DATA2 DATA1 DATA0
0 1 0 0 0
3) The MSP53C691 pulls INRDY low again to request a level 1 command.
The master sends a 1, 2, or 3, depending upon the level of sleep.