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Communication Processor Module
MOTOROLA
MPC823 USER’S MANUAL
16-373
SMC
COMMUNICATION
16
PROCESSOR
MODULE
The receive data source for the two serial management controller channels have different
pin options for each channel. SMC1 can either use the L1RXDA pin of the serial interface or
the SMRXD1 pin if it is connected to the NMSI. SMC2 can also use the L1RXDA pin of the
serial interface, but if you use the SMRXD2 pin the serial interface time-slot assigner
function is not available. Likewise, the transmit data source for SMC1 can be the L1TXDA
pin if the serial management controller is connected to the TDM or the SMTXD1 pin if it is
connected to the NMSI. SMC2 transmit data source can also be L1TXDA pin if the serial
management controller is connected to the TDM, but if you use the SMTXD2 pin the serial
interface time-slot assigner function is not available.
If the serial management controllers are connected to the TDM, the SMC receive and
transmit clocks can be independent from each other, as defined in the CRTA bit of the
information. However, if the serial management controller is connected to the NMSI, the
SMC receive and transmit clocks must be connected to a single clock source called SMCLK,
which is an internal signal name for a clock that is generated from the bank of clocks.
SMCLK originates from an external pin or one of the two internal baud rate generators. Refer
If the serial management controllers are connected to the TDM, it gets its synchronization
pulse from the time-slot assigner. Otherwise, if the serial management controller is
connected to the NMSI and the Transparent protocol is selected, the serial management
controller can use the SMSYNx pin as a synchronization pin to determine when it should
start transmitting and receiving. The SMSYNx pin is not used when the serial
communication controller is in UART mode.
16.11.1 Features
The following is a list of the serial management controllers’ main features:
Each serial management controller can implement the UART protocol on its own pins
Each serial management controller can implement a totally Transparent protocol on a
multiplexed or nonmultiplexed line. If SMC2 uses a nonmultiplexed line, the serial
interface time-slot assigner is not available.
Each SMC channel fully supports the circuit interface and monitor channels of the GCI
(IOM-2) in ISDN applications
Two serial management controllers support the two sets of circuit interface and monitor
channels in the SCIT channels 0 and 1
Full-duplex operation
Local loopback and echo capability for testing