mc68hc908jw32 Freescale Semiconductor, Inc, mc68hc908jw32 Datasheet - Page 174

• Manufacturer Part Number: mc68hc908jw32
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports
13.5 Port D
Port D is a 8-bit general-purpose bidirectional I/O port.
13.5.1 Port D Data Register
The port D data register contains a data latch for each of the eight port D pins.
PTD[7:0] — Port D Data Bits
PTD2, PTD3 and PTD7
13.5.2 Data Direction Register D
Data direction register D determines whether each port D pin is an input or an output. Writing a logic 1 to
a DDRD bit enables the output buffer for the corresponding port D pin; a logic 0 disables the output buffer.
DDRD[7:0] — Data Direction Register D Bits
174
These read/write bits are software programmable. Data direction of each port D pin is under control of
the corresponding bit in data direction register D. Reset has no effect on port D data.
There is programmable pullup associated with the pins. The pullup are default enabled and can be
controlled via POCR2 register.
These read/write bits control port D data direction. Reset clears DDRD[7:0], configuring all port D pins
as inputs.
1 = Corresponding port D pin configured as output
0 = Corresponding port D pin configured as input
Additional Function:
Address:
Avoid glitches on port D pins by writing to the port D data register before
changing data direction register D bits from 0 to 1.
Reset:
Read:
Write:
Address:
Reset:
Read:
Write:
DDRD7
$0007
Bit 7
0
Optional
$0003
Pullup
PTD7
Bit 7
Figure 13-12. Data Direction Register D (DDRD)
Figure 13-11. Port D Data Register (PTD)
DDRD6
= Unimplemented
6
0
PTD6
MC68HC908JW32 Data Sheet, Rev. 5
6
DDRD5
5
0
PTD5
5
NOTE
DDRD4
4
0
Unaffected by reset
PTD4
4
DDRD3
3
0
Optional
Pullup
PTD3
3
DDRD2
2
0
Optional
Pullup
PTD2
2
DDRD1
1
0
PTD1
1
Freescale Semiconductor
DDRD0
Bit 0
0
PTD0
Bit 0