MC68HC908JG16 Datasheet, PDF (261/324 Pages) Motorola, Inc – Microcontrollers

Input/Output (I/O) Ports
Port B
14.4 Port B
Port B is an 1-bit general-purpose bidirectional I/O port with software
configurable pullup.
14.4.1 Port B Data Register
The port B data register contains the data latch for PTB0.
Address: $0001
Bit 7
6
5
4
3
2
1
Bit 0
Read: 0
0
0
0
0
0
0
PTB0
Write:
Reset:
Unaffected by reset
Figure 14-5. Port B Data Register (PTB)
PTB0 — PTB0 Data Bit
This read/write bit is software programmable. Data direction of PTB0
pin is under control of the DDRB0 bit in the data direction register B.
Reset has no effect on port B data.
The port B pullup control bit, PBP, in the port option control register
(POCR) enables the pullup on PTB0 pin if configured as an input.
(See 14.8 Port Options.)
14.4.2 Data Direction Register B
Data direction register B determines whether PTB0 is an input or an
output. Writing a logic 1 to DDRB0 bit enables the output buffer for the
PTB0 pin; a logic 0 disables the output buffer.
Address: $0005
Bit 7
6
5
4
3
2
1
Read: 0
0
0
0
0
0
0
Write:
Reset: 0
0
0
0
0
0
0
Figure 14-6. Data Direction Register B (DDRB)
Bit 0
DDRB0
0
MC68HC908JG16 — Rev. 1.1
Freescale Semiconductor
Input/Output (I/O) Ports
Technical Data
261