s908qc16vdse Freescale Semiconductor, Inc, s908qc16vdse Datasheet - Page 114

• Manufacturer Part Number: s908qc16vdse
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Input/Output Ports (PORTS)
11.5.3 Port C Input Pullup Enable Register
The port C input pullup enable register (PTCPUE) contains a software configurable pullup device for each
of the four port C pins. Each bit is individually configurable and requires the corresponding data direction
register, DDRCx, be configured as input. Each pullup device is automatically and dynamically disabled
when its corresponding DDRCx bit is configured as output.
PTCPUE[3:0] — Port C Input Pullup Enable Bits
11.6 Port D
Port D is an 8-bit general purpose I/O port. Each port D pin can be configured to have an internal pullup
when used as an input port pin.
11.6.1 Port D Data Register
The port D data register (PTD) contains a data latch for each of the eight port D pins.
114
Table 11-3
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
PTCPUE
These read/write bits are software programmable to enable pullup devices on port C pins
Bit
X
1
0
1 = Corresponding port C pin configured to have internal pull if its DDRC bit is set to 0
0 = Pullup device is disconnected on the corresponding port C pin regardless of the state of its
DDRC bit.
summarizes the operation of the port C pins.
Reset:
Reset:
Read:
Write:
Read:
Write:
DDRC
Bit
0
0
1
DD
MC68HC908QC16 • MC68HC908QC8 • MC68HC908QC4 Data Sheet, Rev. 4
Figure 11-12. Port C Input Pullup Enable Register (PTCPUE)
by internal pullup.
PTD7
Bit 7
Bit 7
0
0
PTC
X
Bit
X
X
(1)
= Unimplemented
Figure 11-13. Port D Data Register (PTD)
PTD6
6
0
0
6
Input, Hi-Z
Input, V
Table 11-3. Port C Pin Functions
I/O Pin
Output
Mode
DD
PTD5
5
0
0
5
(2)
(4)
Unaffected by reset
PTD4
4
0
0
4
Accesses to DDRC
DDRC2–DDRC0
DDRC2–DDRC0
DDRC2–DDRC0
Read/Write
PTCPUE3 PTCPUE2 PTCPUE1 PTCPUE0
PTD3
3
0
3
PTD2
2
0
2
PTC3–PTC0
PTD1
Read
1
0
1
Pin
Pin
Accesses to PTC
Freescale Semiconductor
PTD0
Bit 0
Bit 0
0
PTC3–PTC0
PTC3–PTC0
PTC3–PTC0
Write
(3)
(3)