RALCWI Vocoder
CMX608/CMX618/CMX638
6 - 15 Reserved.
Bits 5 and 4
Reserved
These bits should be cleared to '0' for correct device operation.
SEL1 / SEL0 = '10' - Command
7
1
6
0
5
4
3
2
1
0
Command
This sub-register is used for issuing commands to control the various aspects of the interaction of
the device and an external CODEC.
Bits 5-0
Command
This field specifies a command to execute. Bit 5 is the msb.
$00 Reserved.
$01 (ECC_SSP_START)
Starts the SSP. If the CODEC requires initialisation commands and these have been pre-loaded
through the EXCODECCMD register ($12), then these will be sent as soon as the CODEC starts
transferring data.
If the SSP is already running, then this command is ignored and a status value of '0' is returned.
$02 (ECC_SSP_STOP)
Stops the SSP. All activity on the SSP will be ignored.
If the SSP is not running, then this command is ignored and a status value of '0' is returned.
$03 (ECC_FIFO_CLEAR)
Clears the FIFO associated with the EXCODECCMD register ($12). The ECFIFO register ($24)
will also be cleared.
$04 (ECC_FIFO_COUNT)
Places the number of words contained in the FIFO into the ECFIFO register ($24). The ECFIFO
register gets updated by both the ECC_FIFO_CLEAR command and by a write on the
EXCODECCMD register ($12) (which pushes another value into the FIFO), so issuing this
command should be unnecessary.
$05 (ECC_FIFO_DATA)
Places all the words contained in the FIFO into the ENCFRAME register ($30). The ENCFRAME
register is a byte wide streaming register so, for this data, the most significant byte of each word is
sent first. This command should not be issued whilst the device is actively encoding. The
controlling host should first read the ECFIFO register ($24), to get the number of words in the
FIFO. This value should be multiplied by 2 to get the number of bytes that have to be read from
ENCFRAME register ($30).
$06 (ECC_CODEC_RESET)
Places the CODEC in a reset state. The exact effect of this command is CODEC dependant. If
any of the generic CODEC settings are chosen, this command does not do anything. Please refer
to the external CODEC support section.
2014 CML Microsystems Plc
40
D/608_18_38/11
CMLMICRO [ CML MICROCIRCUITS ]
