S908QC16CDRE FREESCALE [Freescale Semiconductor, Inc], S908QC16CDRE Datasheet - Page 112

• Manufacturer Part Number: S908QC16CDRE
• Description: Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Input/Output Ports (PORTS)
11.5 Port C
Port C is an 4-bit general purpose port. PTC3 is an input only port pin, while PTC2–PTC0 can be
configured for either input or output. Each port C pin can be configured to have an internal pullup when
used as an input pin.
11.5.1 Port C Data Register
The port C data register (PTC) contains a data latch for each of the port C pins.
PTC[2:0] — Port C Data Bits
PTC3 — Port C Data Bit
11.5.2 Data Direction Register C
Data direction register C (DDRC) determines whether each port C pin is an input or an output. Writing a 1
to a DDRC bit enables the output buffer for the corresponding port C pin; a 0 disables the output buffer.
112
1. X = don’t care
2. I/O pin pulled to V
3. Writing affects data register, but does not affect input.
4. Hi-Z = high impedance
PTBPUE
These read/write bits are software programmable. Data direction of each port C pin is under the control
of the corresponding bit in data direction register C. Reset has no effect on port C data.
This read-only bit reads the state of the PTC3 pin.
Bit
X
1
0
Reset:
Reset:
Read:
Write:
Read:
Write:
DDRB
Bit
0
0
1
DD
MC68HC908QC16 • MC68HC908QC8 • MC68HC908QC4 Data Sheet, Rev. 2
by internal pullup.
Bit 7
Bit 7
0
0
0
PTB
X
Bit
X
X
(1)
Figure 11-10. Data Direction Register C (DDRC)
= Unimplemented
= Unimplemented
Figure 11-9. Port C Data Register (PTC)
6
0
6
0
0
Input, Hi-Z
Input, V
Table 11-2. Port B Pin Functions
I/O Pin
Output
Mode
DD
5
0
5
0
0
(2)
(4)
Unaffected by reset
4
0
4
0
0
Accesses to DDRB
DDRB7–DDRB0
DDRB7–DDRB0
DDRB7–DDRB0
Read/Write
PTC3
3
3
0
0
DDRC2
PTC2
2
2
0
PTB7–PTB0
DDRC1
PTC1
Read
1
1
0
Pin
Pin
Accesses to PTB
Freescale Semiconductor
DDRC0
PTC0
Bit 0
Bit 0
0
PTB7–PTB0
PTB7–PTB0
PTB7–PTB0
Write
(3)
(3)