Communication Processor Module
16-128
MPC823 USER’S MANUAL
MOTOROLA
SERIAL
I/F
COMMUNICATION
16
PROCESSOR
MODULE
SMC1CS—SMC1 Clock Source (NMSI mode)
SMC1 can take its clocks from one of the baud rate generators or one of four pins from the
bank of clocks. The SMC1 transmit and receive clocks must be the same when it is
connected to the NMSI.
000 = SMC1 transmit and receive clocks are BRG1.
001 = SMC1 transmit and receive clocks are BRG2.
010 = SMC1 transmit and receive clocks are BRG3.
011 = SMC1 transmit and receive clocks are BRG4.
100 = SMC1 transmit and receive clocks are CLK1.
101 = SMC1 transmit and receive clocks are CLK2.
110 = SMC1 transmit and receive clocks are CLK3.
111 = SMC1 transmit and receive clocks are CLK4.
SDMA—Serial Interface Diagnostic Mode for TDMA
00 = Normal operation.
01 = Automatic echo. In this mode, the channel transmitter automatically retransmits
the data received from the TDMA on a bit-by-bit basis. The receive section
operates normally, but the transmit section can only retransmit received data. In
this mode, the L1GRA signal is ignored.
10 = Internal loopback. In this mode, the TDMA transmitter output is internally
connected to the TDMA receiver input (L1TXDA is connected to L1RXDA). The
receiver and transmitter operate normally. The data appears on the L1TXDA pin.
In this mode the L1RQA signal is asserted normally. The L1GRA signal is ignored.
11 = Loopback control. In this mode, the TDMA transmitter output is internally
connected to the TDMA receiver input (L1TXDA is connected to L1RXDA). The
transmitter output (L1TXDA) and the L1RQA pin is inactive. This mode is used to
accomplish loopback testing of the entire TDMA without affecting the external
serial lines.
RFSDA—Receive Frame Sync Delay for TDMA
This field determines the number of clock delays between the receive sync and the first bit
of the receive frame. Even if the CRTA bit is set, these bits do not control the delay for the
transmit frame.
00 = No bit delay. The first bit of the frame is transmitted/received on the same clock
as the sync. Use for GCI.
01 = 1-bit delay. Use for IDL.
10 = 2-bit delay.
11 = 3-bit delay.
Note: In modes 01,10, and 11, the receive and transmit clocks should be identical.