mc68hc908ld64 Freescale Semiconductor, Inc, mc68hc908ld64 Datasheet - Page 304

• Manufacturer Part Number: mc68hc908ld64
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports
19.5.2 Data Direction Register C
Data Sheet
304
NOTE:
NOTE:
Address:
Care must be taken when reading port C while applying analog voltages
to ADC5–ADC0 pins. If the appropriate ADC channel is not enabled,
excessive current drain may occur if analog voltages are applied to the
PTCx/ADCx pin, while PTC is read as a digital input. Those ports not
selected as analog input channels are considered digital I/O ports.
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.
DDRC[6:0] — 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.
Figure 19-12
Reset:
Read:
Write:
These read/write bits control port C data direction. Reset clears
DDRC[6:0], configuring all port C pins as inputs.
1 = Corresponding port C pin configured as output
0 = Corresponding port C pin configured as input
$0006
Bit 7
Figure 19-11. Data Direction Register C (DDRC)
0
0
shows the port C I/O logic.
Input/Output (I/O) Ports
= Unimplemented
DDRC6
6
0
DDRC5
5
0
DDRC4
4
0
DDRC3
3
0
MC68HC908LD64
DDRC2
Freescale Semiconductor
2
0
DDRC1
1
0
—
DDRC0
Rev. 3.0
Bit 0
0