Port 9; Overview; Register Descriptions - Hitachi H8/3035 Series Hardware Manual

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 the
serial communication interface (SCI), and for
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

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.
,54
input. Port 9 has the same set of pin
4
Port 9 pins
P9 (input/output)/SCK (input/output)/IRQ
4
P9 (input/output)/RxD (input)
2
P9 (input/output)/TxD (output)
0
Figure 7-18 Port 9 Pin Configuration
Abbreviation
P9DDR
P9DR
(input)
4
R/W Initial Value
W H'C0
R/W H'C0
143