MPC823 datasheet(11/74 Pages) MOTOROLA

11 / 74 page

Communication Processor Module

MOTOROLA

MPC823 REFERENCE MANUAL

16-389

16.11.5.4 DISABLING PART OF THE SMCx RECEIVER. Follow this shorter sequence to

reinitialize the receive parameters to the state they were in after reset.

1. Clear the REN bit in the SMCMR.

2. INIT RX PARAMETERS command and make any additional modifications.

3. Set the REN bit in the SMCMR.

16.11.5.5 SWITCHING PROTOCOLS. To switch a protocol that is being executed by a

serial management controller without resetting the board or affecting any other serial

management controller:

1. Clear the TEN and REN bits in the SMCMR.

2. Issue the INIT TX AND RX PARAMS command to initialize the transmit and receive

parameters. Make any additional modifications in the SMCMR.

3. Set the TEN and REN bits in the SMCMR. The serial management controller is now

enabled with the new protocol.

16.11.6 The SMCx in UART Mode

Compared to an SCCx in UART mode, the serial management controllers are designed to

support simple debug/monitor ports instead of full-featured UART controllers. The following

is a list of the features that the SMCx in UART mode does not support.

• RTSx, CTSx, and CDx pins

• Receive and transmit sections clocked at different rates

• Fractional stop bits

• Built-in multidrop modes

• Freeze mode for implementing flow control

• Isochronous operation (1

× clock)

• Interrupts on special control character reception

• Ability to transmit data on demand using the transmit on demand register

Tip:

You can save power by clearing the TEN and REN bits of a serial management

controller.

MPC823 데이터시트(PDF) 11 Page - Motorola, Inc