RALCWI Vocoder
CMX608/CMX618/CMX638
ENCFRAME register address $30
7
6
5
4
3
2
1
0
Encoded Frame
This read only register contains the encoded speech data frames. This is a byte wide streaming
register containing up to 36 bytes of data. The amount of data to be read depends on how the
device has been configured with the VCFG register ($07). Bit 7 is the msb.
This register should be read whenever the VDA bit is set in the status register. This indicates that
a frame of vocoded speech is now available. Whilst it is not necessary to read this data out
immediately, it must be read before another frame of vocoded speech is produced.
The frequency of frames is also dependant on the configuration. The following table shows the
amount of data that needs to be read, and the frequency of production against the configuration
setting:
VCFG Register
Description of packet
ENCFRAME
Byte
Count
Prod.
every
7
6
5
4
3
2
1
0
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
0
0
0
0
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
1
0
1
1
1
1
1
0
0
0
0
1
0
1
0
0
1
1
0
0
1
1
0
1
1
0
0
1
0
1
0
1
0
1
0
1
1
0
0
2400bps 1x20ms frame
6
20ms
40ms
60ms
80ms
20ms
40ms
60ms
80ms
60ms
60ms
80ms
80ms
2400bps 2x20ms frames
12
18
24
7
2400bps 3x20ms frames
2400bps 4x20ms frames
2750bps 1x20ms frame
2750bps 2x20ms frames
14
21
28
27
27
36
36
2750bps 3x20ms frames
2750bps 4x20ms frames
2400bps 3x20ms frames with FEC
2750bps 3x20ms frames with FEC
2400bps 4x20ms frames with FEC
2750bps 4x20ms frames with FEC
Table 7 Encoder Packet Description
This register is also used to read the contents of the external CODEC command FIFO. The
CODEC command FIFO is a word (16-bit) FIFO, so the data is presented as two bytes per word:
the first byte being the most significant byte of the word. Please refer to the EXCODECCONT
register ($0B) for more information.
2014 CML Microsystems Plc
45
D/608_18_38/11
CMLMICRO [ CML MICROCIRCUITS ]
