MC68HC705JJ7 Datasheet, PDF (62/164 Pages) Freescale Semiconductor, Inc – Microcontrollers

Parallel Input/Output
4. If the PB4 pin is to be an input to the analog subsystem or a digital input, then the DDRB4 bit must
be cleared. In this case, the PB4 pin can still be read, but the voltage present will be returned as a
binary value. Depending on the external application, the PB4 pulldown may also be disabled by
setting the PDIB4 pulldown inhibit bit. In this case, both the digital and analog functions connected
to this pin can be utilized.
.
Table 7-2. Port B Pin Functions — PB0–PB4
Control Bits
Port B
Pin
Comparator 1
Timer
CMP1 COE1 OPT in COPR OLVL
SWPDI
in MOR
0
PB0
PB1
PB2
X⁽²⁾
X⁽²⁾
X⁽²⁾
0
X⁽²⁾
1
PB3
X⁽²⁾
0
X⁽²⁾ X⁽²⁾
X⁽²⁾
X⁽²⁾
0
1
X⁽²⁾ X⁽²⁾
0
PB4
X⁽²⁾
0
1
0
X⁽²⁾
0
X⁽²⁾
0
1
1
0
X⁽²⁾
X⁽²⁾ X⁽²⁾
X⁽²⁾
1
X⁽²⁾
1
1
1
X⁽²⁾
X⁽²⁾
1. DDRB can always be read or written.
2. Don’t care
Port B
PORTB Access
(Pin or Data
Register)
Result on
Port B Pins
PDIBx _DDRBx⁽¹⁾ Read Write Pulldown Pin
0
0
Pin Data
On
PBx in
1
0
Pin Data
Off
PBx in
X⁽²⁾
0
Pin Data
Off
PBx in
X⁽²⁾
1
Data Data
Off
PBx out
0
0
Pin Data
On
PB4 in
1
0
Pin Data
Off
PB4 in
X⁽²⁾
0
Pin Data
Off
PB4 in
X⁽²⁾
1
Data Data
Off
PB4 out
X⁽²⁾
1
Data Data
Off
PB4 out
X⁽²⁾
1
Data Data
Off
PB4 out
X⁽²⁾
1
1
Data
Off
1
X⁽²⁾
1
1
Data
Off
1
MC68HC705JJ7 • MC68HC705JP7 Advance Information Data Sheet, Rev. 4.1
62
Freescale Semiconductor