Datasheet

Section 16 Multiplex Mode
Rev. 2.00 Aug. 20, 2008 Page 548 of 1198
REJ09B0403-0200
16.4.2 Serial Pin Multiplexed Mode 1
(SMR0 Register [bits SM2, SM1, SM0] = [0 0 1])
This mode is "COM1 snoop mode" with use of SCI_1 and internal registers. DCD, RI, DSR, DTR,
CTS, RTS, RxDF and TxDF of SCIF are connected to COM1. RxD1 of SCI_1 is connected to
RxDF of SCIF internally and TxD1 of SCI_1 is unused.
So, COM2 is not available (N/A) and Rx of COM2 is fixed at 1. RxD3 and TxD3 of SCI_3 are
cross-connected to COM3.
The pin states of DCD, RI, and DSR of COM1 are reflected in bits DCD1, RI1, and DSR1 of the
SMR0 register. The pin state of CTS of COM1 is reflected in bit CTS1 of the SMR1 register.
Figure 16.2 illustrates the pin connection in serial pin multiplexed mode 1.
COM2 COM3
SCI_1 SCI_3
BMC (H8S)
RxD1
TxD1
RxD3
TxD3
Rx Tx Rx Tx
COM1
DCD1
RI1
DSR1
SMR0
SCIF
P24 P25 P26 P27 P64 P65
P86 P87
P51
P50
DCD RI DSR DTR CTS RTS RxDF TxDF
DCD RI DSR DTR CTS RTS Rx Tx
CTS1
DTR1
RTS1
CTS3
SMR1
RTS3
P53 P52
Figure 16.2 Serial Pin Multiplexed Mode 1