MC68HC908GP20 Datasheet, PDF (234/406 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

READ DDRC ($0006)
WRITE DDRC ($0006)
RESET
WRITE PTC ($0002)
V_DD
DDRCx
PTCx
PTCPUEx
READ PTC ($0002)
INTERNAL
PULLUP
DEVICE
PTCx
Figure 16-11. Port C I/O Circuit
When bit DDRCx is a logic 1, reading address $0002 reads the PTCx
data latch. When bit DDRCx is a logic 0, reading address $0002 reads
the voltage level on the pin. The data latch can always be written,
regardless of the state of its data direction bit. Table 16-4 summarizes
the operation of the port C pins.
Table 16-4. Port C Pin Functions
PTCPUE Bit
1
0
DDRC Bit
0
0
PTC Bit
X⁽¹⁾
X
I/O Pin Mode
Input, V_DD(4)
Input, Hi-Z⁽²⁾
Accesses to DDRC
Read/Write
DDRC6–DDRC0
DDRC6–DDRC0
Accesses to PTC
Read
Pin
Pin
Write
PTC6–PTC0⁽³⁾
PTC6–PTC0⁽³⁾
X
1
X
Output
DDRC6–DDRC0 PTC6–PTC0 PTC6–PTC0
Notes:
1. X = Don’t care
2. Hi-Z = High impedance
3. Writing affects data register, but does not affect input.
4. I/O pin pulled up to V_DD by internal pullup device.
Advance Information
234
MC68HC908GP20 — Rev 2.1
Freescale Semiconductor