Description of the Command Codes
3-15
MSP53C691 Software Description
7) The master can now start sending speech data from a file in response to
each lowering of INRDY. Note that, while sending speech data, the DATA4
line must be high, indicating that speech data is being sent. For example,
to send the speech data byte 0x24 to the MSP53C691, the master must
put 0x12 on the data bus in response to the lowering of INRDY. When the
MSP53C691 is again ready to receive the next nibble, the master puts
0x14 on the data bus again.
Most Significant
DATA LINES
DATA4
DATA3
DATA2
DATA1
DATA0
1
X
X
X
X
First nibble sent
1
X
X
X
X
Second through X nibble sent
Least Significant
1
X
X
X
X
Last nibble sent
8) The master can send a command (such as volume control)-between the
speech data while sending speech data. In this case the master first sends
the command header nibble of the command in response to INRDY low
and then sends the required level 1 and/or level 2 parameter nibbles in re-
sponse to each consecutive lowering of INRDY. Note that the master must
ensure that the DATA4 line is also low, indicating that the value in data lines
DATA0–DATA3 is a command. If the master starts sending a command,
then it must send all the parameters of the command back to back in re-
sponse to each lowering of INRDY before reverting back to sending the
rest of the speech file data again.
9) After sending the last nibble of speech data, the master can send dummy
data (0xFF) to the slave in response to each consecutive lowering of
INRDY until the slave detects the end-of-speech data.
10) When the MSP53C691 detects the end-of-speech, it pulls OUTRDY low.
11) The master must then read the data from the bus. Note that only the lower
four bits of the bus are valid data. OUTRDY goes low three more times,
sending a total of four nibbles (0, 0, 5, and 5) if speaking of the phrase was
successful.
12) INRDY goes low again, indicating that the MSP53C691 is ready to receive
a new command.
3.5.4.2
Speaking CELP, MELP, ADPCM in 8-Bit Data Transfer Mode
Data is sent over an eight-bit interface (DATA0–DATA7). Sending commands
while speaking is not supported in this mode. When the speaking of a phrase
is finished, the master can again send any command over the DATA0–DATA3
lines along with pulling DATA4 line low in response to the next lowering of
INRDY. In other words, the MSP53C691 goes back to the four-bit mode after
it finishes speaking a phrase in eight-bit mode. The master must send the
command header (4) and level 1 parameter (2) to speak a phrase again in
eight-bit mode.
Summary of Contents for MSP53C691
Page 1: ...MSP53C691 Speech Synthesizer December 2000 MSDS Speech User s Guide SPSU020 ...
Page 22: ...2 10 ...
Page 96: ...C 6 ...