MC68HC05K0 Datasheet, PDF (66/154 Pages) Freescale Semiconductor, Inc – HCMOS Microcontroller Unit

Technical Data
Freescale Semiconductor, Inc.
7.3 Port A
Port A is an 8-bit, general-purpose, bidirectional I/O port with these
features:
• Programmable pulldown devices (mask option)
• 8-mA current sinking capability (pins PA7–PA4)
• External interrupt capability (pins PA3–PA0) (mask option)
7.3.1 Port A Data Register
The port A data register (PORTA), shown in Figure 7-1, contains a bit
for each of the port A pins. When a port A pin is programmed to be an
output, the state of its data register bit determines the state of the output
pin. When a port A pin is programmed to be an input, reading the port A
data register returns the logic state of the pin. The port A data register
may be written to while the port is either an input or an output.
Address: $0000
Bit 7
6
5
4
3
2
1
Bit 0
Read:
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
Write:
Reset:
Unaffected by reset
Figure 7-1. Port A Data Register (PORTA)
PA7–PA0 — Port A 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 A. Reset has no effect on port A data.
Technical Data
MC68HC05K0 • MC68HC05K1 — Rev. 2.0
Parallel Input/Output (I/O)
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