Rev. 5.00, 09/03, page 438 of 760
Bit 5—Transmit Enable (TE): Enables or disables the SCI serial transmitter.
Bit 5: TE Description
0 Transmitter disabled
*
1
(Initial value)
1 Transmitter enabled
*
2
Notes: 1. The transmit data register empty bit (TDRE) in the serial status register (SCSSR) is
fixed at 1.
2. Serial transmission starts when the transmit data register empty (TDRE) bit in the serial
status register (SCSSR) is cleared to 0 after writing of transmit data into the SCTDR.
Select the transmit format in SCSMR before setting TE to 1.
Bit 4—Receive Enable (RE): Enables or disables the SCI serial receiver.
Bit 4: RE Description
0 Receiver disabled
*
1
(Initial value)
1 Receiver enabled
*
2
Notes: 1. Clearing RE to 0 does not affect the receive flags (RDRF, FER, PER, ORER). These
flags retain their previous values.
2. Serial reception starts when a start bit is detected in asynchronous mode, or
synchronous clock input is detected in synchronous mode. Select the receive format in
SCSMR before setting RE to 1.
Bit 3—Multiprocessor Interrupt Enable (MPIE): Enables or disables multiprocessor interrupts.
The MPIE setting is used only in asynchronous mode, and only if the multiprocessor mode bit
(MP) in the serial mode register (SCSMR) is set to 1 during reception. 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)
(Initial value)
[Clearing conditions]
(1) MPE is cleared to 0 when MPIE is cleared to 0.
(2) The multiprocessor bit (MPB) is set to 1 in receive data.
1 Multiprocessor interrupts are enabled
*
Receive-data-full interrupt requests (RXI), receive-error interrupt requests (ERI),
and setting of the RDRF, FER, and ORER status flags in the serial status register
(SCSSR) are disabled until data with a multiprocessor bit of 1 is received.
Note: * The SCI does not transfer receive data from SCRSR to SCRDR, does not detect receive
errors, and does not set the RDRF, FER, and ORER flags in the serial status register
(SCSSR). When it receives data that includes MPB = 1, the SCSSR’s MPB flag is set to 1,
and the SCI automatically clears MPIE to 0, generates RXI and ERI interrupts (if the TIE
and RIE bits in the SCSCR are set to 1), and allows the FER and ORER bits to be set.