Datasheet
Section 9 I/O Ports 
    Rev. 3.00 Mar. 15, 2006 Page 145 of 526 
   REJ09B0060-0300 
9.9 Port B 
Port B is an input port also functioning as an A/D converter analog input pin. Each pin of the port 
B is shown in figure 9.9. 
PB5/AN5
PB6/AN6
PB7/AN7
PB0/AN0
PB4/AN4
PB3/AN3
PB2/AN2
PB1/AN1
Port B
Figure 9.9 Port B Pin Configuration 
Port B has the following register. 
•  Port data register B (PDRB) 
9.9.1  Port Data Register B (PDRB) 
PDRB is a general input-only port data register of port B. 
Bit Bit Name 
Initial 
Value R/W Description 
7 
6 
5 
4 
3 
2 
1 
0 
PB7 
PB6 
PB5 
PB4 
PB3 
PB2 
PB1 
PB0 
 
 
 
 
 
 
 
 
R 
R 
R 
R 
R 
R 
R 
R 
The input value of each pin is read by reading this 
register. 
However, if a port B pin is designated as an analog 
input channel by ADCSR of A/D converter, 0 is read. 










