Serial Pin Multiplexed Mode - Renesas H8S Family Hardware Manual

Section 16 Multiplex Mode

16.4.4

(SMR0 Register [bits SM2, SM1, SM0] = [0 1 1])

This mode enables the use of COM2 by SCIF and COM1 by SCI_1. Since SCI_1 doesn't use any

hardware pins for flow control, emulation is possible using the internal registers.

Tx/Rx of COM1 are connected to RxD1/TxD1 of SCI_1, and other COM1 port signals are

controlled or monitored through bits in the internal registers. RxDF/TxDF of SCIF are connected

to Tx/Rx of COM2 and other SCIF signals are not used. DCD/RI/DSR/CTS of SCIF are fixed at 1.

RxD3 and TxD3 of SCI_3 are connected to Tx and Rx of COM3.

The states of DCD/RI/DSR of COM1 are reflected in bits DCD1/RI1/DSR1 of the SMR0 register,

and CTS of COM1 is reflected in bit CTS1 of the SMR1 register.

The values written to bits DTR1/RTS1 of the SMR1 register are output to DTR/RTS of COM1.

Figure 16.4 illustrates the pin connection in serial pin multiplexed mode 3.

Rev. 1.00 Mar. 12, 2008 Page 548 of 1178

REJ09B0403-0100

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Figure 16.4 Serial Pin Multiplexed Mode 3