mc68hc908sr12 Freescale Semiconductor, Inc, mc68hc908sr12 Datasheet - Page 329

• Manufacturer Part Number: mc68hc908sr12
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

18.5.2 Data Direction Register C (DDRC)
MC68HC908SR12•MC68HC08SR12 — Rev. 5.0
Freescale Semiconductor
NOTE:
NOTE:
Address:
Data direction register C 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.
DDRC[7:0] — Data Direction Register C Bits
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.
the port C I/O logic.
For those devices packaged in a 42-pin shrink dual in-line package,
PTC6 and PTC7 are not connected. DDRC6 and DDRC7 should be set
to a 1 to configure PTC6 and PTC7 as outputs.
Reset:
Read:
Write:
These read/write bits control port C data direction. Reset clears
DDRC[7:0], configuring all port C pins as inputs.
1 = Corresponding port C pin configured as output
0 = Corresponding port C pin configured as input
DDRC7
READ DDRC ($0006)
WRITE DDRC ($0006)
WRITE PTC ($0002)
READ PTC ($0002)
$0006
Bit 7
Figure 18-10. Data Direction Register B (DDRB)
0
Input/Output (I/O) Ports
DDRC6
6
0
Figure 18-11. Port C I/O Circuit
RESET
DDRC5
5
0
DDRC4
DDRCx
PTCx
4
0
DDRC3
3
0
DDRC2
Figure 18-11
2
0
Input/Output (I/O) Ports
DDRC1
1
0
Data Sheet
shows
DDRC0
Bit 0
Port C
0
PTCx
329