Freescale Semiconductor, Inc.
Parallel Input/Output (I/O)
Port B
7.4 Port B
Port B is an 8-bit, general-purpose, bidirectional I/O port. Port B pins can
also be configured to function as external interrupts. The port B pullup
devices are enabled in mask option register 1 (MOR1). See 9.5.2 Mask
Option Register 1 and 4.3.3 Port B Interrupts.
7.4.1 Port B Data Register
The port B data register (PORTB) shown in Figure 7-4 contains a data
latch for each of the eight port B pins.
Address: $0001
Bit 7
6
5
4
3
2
1
Bit 0
PB0
Read:
Write:
Reset:
PB7
PB6
PB5
PB4
PB3
PB2
PB1
Unaffected by reset
Figure 7-4. Port B Data Register (PORTB)
PB7–PB0 — Port B Data Bits
These read/write bits are software programmable. Data direction of
each bit is under the control of the corresponding bit in data direction
register B. Reset has no effect on port B data.
MC68HC705C8A — Rev. 3
MOTOROLA
Technical Data
Parallel Input/Output (I/O)
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