HD6433802H Datasheet, PDF (183/435 Pages) Hitachi Semiconductor – Single-Chip Microcomputer

8.10 Port B
8.10.1 Overview
Port B is a 4-bit input-only port, configured as shown in figure 8.9.
PB₃/AN₃/IRQ₁
Port B
PB₂/AN₂
PB₁/AN₁
PB₀/AN₀
Figure 8.9 Port B Pin Configuration
8.10.2 Register Configuration and Description
Table 8.26 shows the port B register configuration.
Table 8.26 Port B Register
Name
Port data register B
Port mode register B
Abbrev.
R/W
PDRB
R
PMRB
R/W
Initial Value
—
H'F7
Address
H'FFDE
H'FFEE
1. Port Data Register B (PDRB)
Bit
7
6
5
—
—
—
4
3
2
1
0
—
PB ₃
PB₂
PB₁
PB ₀
Read/Write
—
—
—
—
R
R
R
R
Reading PDRB always gives the pin states. However, if a port B pin is selected as an analog input
channel for the A/D converter by AMR bits CH3 to CH0, that pin reads 0 regardless of the input
voltage.
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