Bit 4—Receive Enable (RE):
Enables or disables the start of SCI serial receiving operations.
Bit 4
RE
Description
0
Receiving disabled
*
1
(Initial value)
1
Receiving enabled
*
2
Notes: 1. Clearing the RE bit to 0 does not affect the RDRF, FER, PER, and ORER flags. These
flags retain their previous values.
2. In the enabled state, serial receiving starts when a start bit is detected in asynchronous
mode, or serial clock input is detected in synchronous mode. Select the receive format
in SMR before setting the RE bit to 1.
Bit 3—Multiprocessor Interrupt Enable (MPIE):
Enables or disables multiprocessor interrupts.
The MPIE setting is valid only in asynchronous mode, and only if the MP bit is set to 1 in SMR.
The MPIE setting is ignored in synchronous mode or when the MP bit is cleared to 0.
Bit 3
MPIE
Description
0
Multiprocessor interrupts are disabled (normal receive operation)
[Clearing conditions]
The MPIE bit is cleared to 0.
MPB = 1 in received data.
(Initial value)
1
Multiprocessor interrupts are enabled
*
Receive-data-full interrupts (RXI), receive-error interrupts (ERI), and setting of the RDRF,
FER, and ORER status flags in SSR are disabled until data with the multiprocessor bit
set to 1 is received.
Note:
*
The SCI does not transfer receive data from RSR to RDR, does not detect receive errors,
and does not set the RDRF, FER, and ORER flags in SSR. When it receives data in which
MPB = 1, the SCI sets the MPB bit to 1 in SSR, automatically clears the MPIE bit to 0,
enables RXI and ERI interrupts (if the RIE bit is set to 1 in SCR), and allows the FER and
ORER flags to be set.
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