CMX608 Datasheet, PDF (44/70 Pages) CML Microcircuits – Integrated Input and Output Channel Filters

RALCWI Vocoder
CMX608/CMX618/CMX638
5.10.3. 8 Bit Read-Only Registers
ECFIFO register address $24
7
6
5
4
3
2
1
0
FIFO Word Count
This read-only register holds the current count of words in the external CODEC control FIFO. The
FIFO can currently hold up to 16 words for external CODEC control. This register is updated
whenever the EXCODECCMD register ($12) is written, or the EXCODECCONT register ($0B) is
written with ECC_FIFO_CLEAR or ECC_FIFO_COUNT. Bit 7 is the msb.
SVCACK register address $2E
7
6
5
4
3
2
1
0
X
X
X
X
X
X
X
ACK
This read-only register contains the acknowledgement result from a service request or some other
operation, as detailed in the STATUS register ($40). The contents of this register are only valid
after status bit 14 or 15 (in certain cases) has been set, and before another C-BUS register is
written. See section 6.7 for further details.
Bit 0
ACK
Bits 1 to 7
This bit is set to '1' to indicate a success result.
This bit is cleared to '0' to indicate an error or unsuccessful result.
These bits are undefined.
FRAMETYPER register address $2F
7
6
Frame 4
5
4
Frame 3
3
2
Frame 2
1
0
Frame 1
This read-only register contains the frame type for each of the 20ms raw Vocoder frames. The
information in this register is used when the device is configured to produce raw Vocoder frames
without any FEC and the DTX (discontinuous transmission) option is enabled. If the DTX option is
disabled, the value in this register is undefined.
The device can be set to encode over a period of 20ms, 40ms, 60ms or 80ms, producing 1, 2, 3 or
4 frames. For each frame, this register holds the corresponding 2-bit frame type attribute.
Bit 1/3/5/7
0
0
1
1
Bit 0/2/4/6
0
1
0
1
Frame Type
Data frame
reserved
SID frame
reserved
For a data frame, the full frame must be transmitted across the channel. For the SID frame, only
the first 18 bits of the frame need to be sent. In all cases, the frame type attribute must be sent.
NOTE: The same number of bytes must be read from the ENCFRAME register ($30), regardless
of frame type. This information indicates how much of it must be sent across the communications
channel.
 2014 CML Microsystems Plc
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D/608_18_38/11