Freescale Semiconductor PowerQUICC MPC885 Reference Manual page 672

Serial Communications Controllers
21.4.7.2 Reset Sequence for an SCC Transmitter
The following steps reinitialize an SCC transmit parameters to the reset state:
1. Clear GSMR_L[ENT].
2. Make any modifications then issue the
3. Set GSMR_L[ENT].
21.4.7.3 General Reconfiguration Sequence for an SCC Receiver
An SCC receiver can be reconfigured by following these steps:
1. Clear GSMR_L[ENR]. The SCC receiver is now disabled and put in a reset state.
2. Modify SCC Rx parameters or parameter RAM. To switch protocols or restore Rx parameters to
their initial state, issue an
3. If the
INIT RX PARAMETERS
command.
4. Set GSMR_L[ENR]. Reception begins using the RxBD pointed to by RBPTR, assuming the E bit
is set.
21.4.7.4 Reset Sequence for an SCC Receiver
To reinitialize the SCC receiver to the state it was in after reset, follow these steps:
1. Clear GSMR_L[ENR].
2. Make any modifications then issue the
3. Set GSMR_L[ENR].
21.4.7.5 Switching Protocols
To switch an SCC's protocol without resetting the board or affecting other SCCs, follow these steps:
1. Clear GSMR_L[ENT, ENR].
2. Make protocol changes in the GSMR and additional parameters then issue the
command to initialize both Tx and Rx parameters.
PARAMETERS
3. Set GSMR_L[ENT, ENR] to enable the SCC with the new protocol.
21.4.8 Saving Power
To save power when not in use, an SCC can be disabled by clearing GSMR_L[ENT, ENR].
21-26
INIT TX PARAMETERS
INIT RX PARAMETERS
command was not issued in step 2, issue an
INIT RX PARAMETERS
MPC885 PowerQUICC Family Reference Manual, Rev. 2
command.
command.
ENTER HUNT MODE
command.
and
INIT TX RX
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