mc68hc05jp6pe Freescale Semiconductor, Inc, mc68hc05jp6pe Datasheet - Page 102

• Manufacturer Part Number: mc68hc05jp6pe
• Description: M68hc05 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Parallel Input/Output
7.6 Port Transitions
General Release Specification
102
* DDRC can always be read or written.
X = Don’t Care
High Nibble
Low Nibble
Port C
Pin(s)
PC0
PC1
PC2
PC3
PC4
PC5
PC6
PC7
Option
Inhibit
down
Mask
Pull-
X
X
0
0
1
0
0
1
Table 7-4. Port C Pin Functions (MC68HC05JP6)
PDICH
Glitches and temporary floating inputs can occur if the control bits
regarding each port I/O pin are not performed in the correct sequence.
X
X
X
X
X
X
Control Bits
0
1
•
•
•
•
Do not use read-modify-write instructions on pulldown register A
or B.
Avoid glitches on port pins by writing to the port data register
before changing data direction register bits from a logic zero to a
logic one.
Avoid a floating port input by clearing its pulldown register bit
before changing its data direction register bit from a logic one to a
logic zero.
A mask option turns off all port pulldown devices and disables
software control of the pulldown devices. Reset has no effect on
the pulldown devices if they are not selected by mask option.
Port C
PDICL
X
X
X
X
X
X
0
1
Parallel Input/Output
DDRCn*
0
0
0
1
0
0
0
1
(Pin or Data Register)
Read
DATA
DATA
PIN
PIN
PIN
PIN
PIN
PIN
PORTC Access
MC68HC05JJ6/MC68HC05JP6
Write
DATA
DATA
DATA
DATA
DATA
DATA
DATA
DATA
Pulldown
Freescale Semiconductor
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
Port C Pins
Result on
PCn OUT
PCn OUT
PCn IN
PCn IN
PCn IN
PCn IN
PCn IN
PCn IN
—
Pin
Rev. 3.2