CMX7163 QAM Modem
CMX7163
C-BUS Operation
Write $0033 to Rx
Tracking - $66 write
Write $0401 to Modem
Mode and Control - $6B
write
Action
Select tracking modes
Description
Selects automatic I/Q dc offset correction and
symbol timing tracking
Initiates a frame sync search, searching for
Frame Sync 1. Once it is detected then Rx data
will be made available
Start reception
-
Apply input signal
The input signal should contain preamble,
Frame Sync 1 and then raw data. The frame
sync should be detected and Rx data made
available
Poll the IRQ Status -
$7E read register for bit
8 – Cmd Done = 1
Read the Receive FIFO
Data Byte (see Receive
FIFO Data/Control -
$4C, $4D, $4E read) 4
times
Wait for data
This indicates that the 4 data bytes requested
have been received and are available
Retrieve the received
data
Data is read from the Receive Data FIFO. Once
4 data bytes are read the IRQ Status register
may be polled again to check if more data is
available if required, and then those data bytes
read. This step may be repeated as many times
as needed
-
End of reception
Once enough data has been received a mode
change (using the Modem Mode and Control -
$6B write register) will stop reception or start
searching for another frame sync
The procedure described above can be adapted, making reception of different numbers of bytes, bits or
coded blocks possible.
The registers used for basic transmission and reception are:
10.1.18 Modem Mode and Control - $6B write
10.1.37 IRQ Status - $7E read
10.1.3 Modem Command FIFO Data/Control - $48, $49 and $4A write
10.1.26 Receive FIFO Data/Control - $4C, $4D, $4E read
10.1.4 FIFO Control - $50 write
10.1.15 Rx Tracking - $66 write
7.4.3 Device Configuration (Using the Programming Register)
While in Idle mode the Programming register becomes active. The Programming register provides access
to the Program Blocks. Program Blocks allow configuration of the CMX7163 during major mode change.
Features that can be configured include:
Flexible selection of Baud rates, from 2k to 20k baud
Pre-amble and frame syncs to be using in transmit and receive
Selection of Automatic control of 4 x GPIO and the RAMDAC during transmission
Configuration of RAMDAC profile
Configuration of RSSI averaging
Configuration of the carrier sense window and thresholds
Configuration of System Clock outputs
Configuration of SPI Thru-Port rate and word format
Configuration of AGC commands using the SPI Thru-Port.
Full details of how to configure these aspects of device operation are given in section 10.2 in the User
Manual.
2014 CML Microsystems Plc
Page 27
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CMLMICRO [ CML MICROCIRCUITS ]
