MC68HC908MR8 Datasheet, PDF (288/372 Pages) Motorola, Inc – Microcontrollers

Input/Output (I/O) Ports
14.5.2 Data Direction Register C
Data direction register C (DDRC) determines whether each port C pin is
an input or an output. Writing a logic 1 to a DDRC bit enables the output
buffer for the corresponding port C pin; a logic 0 disables the output
buffer.
Ad-
dress:
$0006
Bit 7
6
5
4
3
2
1
Bit 0
Read:
Write:
DDRC1 DDRC0
Reset: U
U
U
U
U
U
0
0
= Unimplemented U = Unaffected
Figure 14-9. Data Direction Register C (DDRC)
DDRC[1:0] — Data Direction Register C Bits
These read/write bits control port C data direction. Reset clears
DDRC[1:0], configuring all port C pins as inputs.
1 = Corresponding port C pin configured as output
0 = Corresponding port C pin configured as input
NOTE: Avoid glitches on port C pins by writing to the port C data register before
changing data direction register C bits from 0 to 1.
Figure 14-10 shows the port C I/O logic.
Technical Data
288
Input/Output (I/O) Ports
MC68HC908MR8 — Rev 4.1
Freescale Semiconductor