7733 datasheet(849/940 Pages) RENESAS

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SERIAL I/O

7736 Group User’s Manual

8–3

8.2.9 Port P8 direction register

I/O pins of UARTi are multiplexed with ports P8 and P9. When using pins P82 and P86 as serial data input

pins (RxDi), set the corresponding bits of the port P8 direction register to “0” to set this port for the input

_________ _________

mode. When using pins P80, P81, P83–P85 and P87 as UARTi’s I/O pins (CTSi/RTSi, CLKi, TxDi), these pins

are forcibly set as the UARTi’s I/O pins, regardless of the port P8 direction register’s contents. Also, as

for CLKS0 and CLKS1, refer to section “8.3.1 (4) Number of transfer clock output pins (UART0)” in part

1. Figure 8.2.16 shows the relationship between the port P8 direction register and UARTi’s I/O pins.

When using UART2, pins P90–P93 are forcibly set as the UART2’s input or output pins.

Note that the functions of the UARTi’s I/O pins can be switched by software. For details, refer to the

description of each operating mode.

8.2 Block description

Pin P80/CTS0/RTS0/CLKS1

Pin P82/RxD0/CLKS0

Pin P83/TxD0

Pin P84/CTS1/RTS1

Pin P86/RxD1

Pin P85/CLK1

Port P8 direction register (address 1416)

Pin P81/CLK0

Pin P87/TxD1

Corresponding pin name

Functions

Bit

At reset

0: Input mode

1: Output mode

When using pins P82

and P86 as serial data’s

input pins (RxD0, RxD1),

set the corresponding

bits to “0.”

Note: For pins CLKS0 and CLKS1, refer to section “8.3.1 (4) Number of transfer clock

output pins (UART0)” in part 1.

Fig. 8.2.16 Relationship between port P8 direction register and UARTi’s I/O pins

7733 Datasheet(PDF) 849 Page - Renesas Technology Corp