Port B - Hitachi H8/3022 Hardware Manual

7.11 Port B

7.11.1 Overview
Port B is an 7-bit input/output port that is also used for TPC output (TP
input/output (TIOCB
ADTRG input to the A/D converter. Port B has the same set of pin functions in all operating
modes. Figure 7-23 shows the pin configuration of port B.
Pins in port B can drive one TTL load and a 30-pF capacitive load. They can also drive an LED or
a Darlington transistor pair. Pins PB
Port B
7.11.2 Register Descriptions
Table 7-17 summarizes the registers of port B.
Table 7-17 Port B Registers
Address* Name
H'FFD4 Port B data direction register
H'FFD6 Port B data register
Note: * Lower 16 bits of the address.
, TIOCB , TIOCA
4 3 4
to PB
3
Port B pins
PB (input/output)/TP
7
PB (input/output)/TP
5
PB (input/output)/TP
4
PB (input/output)/TP
3
PB (input/output)/TP
2
PB (input/output)/TP
1
PB (input/output)/TP
0
Figure 7-23 Port B Pin Configuration
, TIOCA ) and ITU output (TOCXB
3
have Schmitt-trigger inputs.
0
(output)/ADTRG (input)
15
(output)/TOCXB (output)
13
(output)/TOCXA (output)
12
(output)/TIOCB (input/output)
11
(output)/TIOCA (input/output)
10
(output)/TIOCB (input/output)
9
(output)/TIOCA (input/output)
8
Abbreviation
PBDDR
PBDR
, TP to TP ), ITU
15 13 8
, TOCXA
4 4
4
4
4
4
3
3
R/W Initial Value
W H'00
R/W H'00
), and
173