HD6473032F Datasheet, PDF (165/572 Pages) Hitachi Semiconductor – Hitachi Microcomputer

7.9 Port 9
7.9.1 Overview
Port 9 is a 3-bit input/output port that is also used for input and output (TxD, RxD, SCK) by serial
communication interface (SCI), and for IRQ₄ input. Port 9 has the same set of pin functions in all
operating modes. Figure 7-18 shows the pin configuration of port 9.
Pins in port 9 can drive one TTL load and a 30-pF capacitive load. They can also drive a darlington
transistor pair.
Port 9
Port 9 pins
P9₄ (input/output)/SCK (input/output)/IRQ₄ (input)
P9₂ (input/output)/RxD (input)
P9₀ (input/output)/TxD (output)
Figure 7-18 Port 9 Pin Configuration
7.9.2 Register Descriptions
Table 7-13 summarizes the registers of port 9.
Table 7-13 Port 9 Registers
Address* Name
H'FFD0
Port 9 data direction register
H'FFD2
Port 9 data register
Note: * Lower 16 bits of the address.
Abbreviation R/W
P9DDR
W
P9DR
R/W
Initial Value
H'C0
H'C0
150