MC68HC05K0 Datasheet, PDF (75/154 Pages) Freescale Semiconductor, Inc – HCMOS Microcontroller Unit

Freescale Semiconductor, Inc.
Parallel Input/Output (I/O)
Port B
When a port B pin is programmed as an output, reading the port bit reads
the value of the data latch and not the voltage on the pin itself. When a
port B pin is programmed as an input, reading the port bit reads the
voltage level on the pin. The data latch can always be written, regardless
of the state of its DDR bit. Table 7-2 and Table 7-3 summarize the
operation of the port B pins.
Table 7-2. PB0 Pin Functions
Pulldown
Mask
Option
No
No
Control Bits
PDIB0
X
X
DDRB0
0
1
Yes
0
0
Yes
0
1
Yes
1
0
Yes
1
1
X = Don’t care
U = Undefined
PB0
Pin Mode
Input, hi-z
Output
Input,
pulldown on
Output
Input, hi-z
Output
Accesses
to PDRB
Read Write
U
PDIB0
U
PDIB0
U
PDIB0
U
PDIB0
U
PDIB0
U
PDIB0
Accesses
to DDRB
Read/Write
DDRB0
DDRB0
DDRB0
DDRB0
DDRB0
DDRB0
Accesses
to PORTB
Read Write
Pin
PB0
PB0
PB0
Pin
PB0
PB0
PB0
Pin
PB0
PB0
PB0
Table 7-3. PB1/OSC3 Pin Functions
Mask Options
3-Pin Osc.
No
No
Pulldowns
No
No
No
Yes
No
Yes
No
Yes
No
Yes
X = Don’t care
U = Undefined
Control Bits
PDIB1 DDRB1
X
0
X
1
0
0
0
1
1
0
1
1
PB1/OSC3
Pin Mode
Input, hi-z
Output
Input,
pulldown on
Output
Input, hi-z
Output
Accesses
to PDRB
Read Write
U PDIB1
U PDIB1
U PDIB1
U PDIB1
U PDIB1
U PDIB1
Accesses
to DDRB
Read/Write
DDRB1
DDRB1
DDRB1
DDRB1
DDRB1
DDRB1
Accesses
to PORTB
Read Write
Pin PB1
PB1 PB1
Pin PB1
PB1 PB1
Pin PB1
PB1 PB1
MC68HC05K0 • MC68HC05K1 — Rev. 2.0
Parallel Input/Output (I/O)
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Technical Data