Freescale Semiconductor PowerQUICC MPC885 Reference Manual page 796

Serial Management Controllers (SMCs)
The receive data source can be L1RXDa if the SMC is connected to the TDM channel of the SI or SMRXD
if it is connected to the NMSI. Likewise, the transmit data source can be L1TXD if using the TDM or
SMTXD if using the NMSI.
If the SMC is connected to the TDM, the SMC receive and transmit clocks can be independent from each
other, as defined in Chapter 20, "Serial Interface."
and transmit clocks must be connected to a single clock source (SMCLK), an internal signal name for a
clock generated from the bank of clocks. SMCLK originates from an external pin or one of the four internal
BRGs. See Section 20.3, "NMSI Configuration."
An SMC connected to a TDM derives a synchronization pulse from the TSA. An SMC connected to the
NMSI using transparent protocol can use SMSYN for synchronization to determine when to start a
transfer. SMSYN is not used when the SMC is in UART mode.
29.1 SMC Features
The following is a list of the main SMC features:
• Each SMC can implement the UART protocol on its own pins
• Each SMC can implement a totally transparent protocol on a multiplexed (TDM) or
non-multiplexed (NMSI) line. The transparent mode can also be used for a fast connection between
MPC885s.
• Each SMC channel fully supports the C/I and monitor channels of the GCI (IOM-2) in ISDN
applications
• Two SMCs support the two sets of C/I and monitor channels in the SCIT channels 0 and 1
• Full-duplex operation
• Local loopback and echo capability for testing
29.2 Common SMC Settings and Configurations
The following sections describe settings and configurations that are common to the serial management
controllers.
29.2.1 SMC Mode Registers (SMCMR n )
The two SMC mode registers (SMCMR), shown in
mode-specific parameters. The functions of SMCMR[8–15] are the same for each protocol. SMCMR[0–7]
vary according to the protocol selected by SMCMR[SM].
29-2
However, if the SMC is connected to the NMSI, receive
Figure
MPC885 PowerQUICC Family Reference Manual, Rev. 2
29-2, select the SMC mode as well as
Freescale Semiconductor