CMX983 Datasheet, PDF (44/93 Pages) CML Microcircuits – Programmable Channel Filter

Analogue Front End (AFE) for Digital Radio
11 Serial Ports
11.1 Rx Serial Port
CMX983
Figure 15 Rx Serial Port
Data from Rx channel A and B are output from the CMX983 through a PCM serial port (Figure 15). PCM data
is sent in Short Frame Sync mode with the CMX983 acting as a master. The PCM clock RXCLK is divided
down from the system clock CLK, and data transmission is most significant bit first. If both Rx Channel A and
B are selected, the two 16-bit data words are multiplexed through a single output data pin RXD as shown in
Figure 16. If only one of the two Rx channels is selected, then the 16-bit serial port shift register for the
disabled channel is bypassed and only the data for the selected channel is shifted out (example shown in
Figure 17).
t_{CYC_RXCLK}
RXCLK
RXFS
t_{CYC_RXFS}
RXD
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Channel A data
Channel B data
15 14 13
Figure 16 Rx Port Timing (Channel A and B both selected)
 2015 CML Microsystems Plc
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D/983/6