Freescale Semiconductor MPC8260 - Manual (Page 821)

Serial Management Controllers (SMCs)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 27-9
27.2.4.1 SMC Transmitter Full Sequence
Follow these steps to fully enable or disable the SMC transmitter:
1. If the SMC is sending data, issue a STOP TRANSMIT command to stop transmission smoothly. If the
SMC is not sending, if TBPTR is overwritten, or if an INIT TX PARAMETERS command is executed,
this command is not required.
2. Clear SMCMR[TEN] to disable the SMC transmitter and put it in reset state.
3. Update SMC transmit parameters, including the parameter RAM. To switch protocols or
reinitialize parameters, issue an INIT TX PARAMETERS command.
4. Issue a RESTART TRANSMIT if an INIT TX PARAMETERS was issued in step 3.
5. Set SMCMR[TEN]. Transmission now begins using the TxBD that the TBPTR value pointed to as
soon as the R bit is set in the TxBD.
27.2.4.2 SMC Transmitter Shortcut Sequence
This shorter sequence reinitializes transmit parameters to the state they had after reset.
1. Clear SMCMR[TEN].
2. Issue an INIT TX PARAMETERS command and make any additional changes.
3. Set SMCMR[TEN].
27.2.4.3 SMC Receiver Full Sequence
Follow these steps to fully enable or disable the receiver:
1. Clear SMCMR[REN]. Reception is aborted immediately, which disables the SMC receiver and
puts it in a reset state.
2. Modify SMC receive parameters, including parameter RAM. To switch protocols or reinitialize
SMC receive parameters, issue an INIT RX PARAMETERS command.
3. Issue a CLOSE RXBD command if INIT RX PARAMETERS was not issued in step 2.
4. Set SMCMR[REN]. Reception immediately uses the RxBD that RBPTR pointed to if E is set in
the RxBD.
27.2.4.4 SMC Receiver Shortcut Sequence
This shorter sequence reinitializes receive parameters to their state after reset.
1. Clear SMCMR[REN].
2. Issue an INIT RX PARAMETERS command and make any additional changes.
3. Set SMCMR[REN].
27.2.4.5 Switching Protocols
To switch the protocol that the SMC is executing without resetting the board or affecting any other SMC,
use one command and follow these steps:
1. Clear SMCMR[REN] and SMCMR[TEN].