mc68hc908gr8a Freescale Semiconductor, Inc, mc68hc908gr8a Datasheet - Page 123

• Manufacturer Part Number: mc68hc908gr8a
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Figure 12-11
When bit DDRCx is a 1, reading address $0002 reads the PTCx data latch. When bit DDRCx is a 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.
Freescale Semiconductor
1. X = Don’t care
2. I/O pin pulled up to V
3. Writing affects data register, but does not affect input.
4. Hi-Z = High impedance
PTCPUE
Bit
X
1
0
shows the port C I/O logic.
DDRC
Bit
0
0
1
DD
READ DDRC ($0006)
WRITE DDRC ($0006)
WRITE PTC ($0002)
READ PTC ($0002)
by internal pullup device.
PTC
X
Bit
X
X
(1)
MC68HC908GR8A • MC68HC908GR4A Data Sheet, Rev. 5
Input, Hi-Z
Input, V
Table 12-4. Port C Pin Functions
RESET
Figure 12-11. Port C I/O Circuit
I/O Pin
Output
Mode
DD
(2)
(4)
Table 12-4
Accesses to DDRC
DDRCx
PTCx
DDRC1–DDRC0
DDRC1–DDRC0
DDRC1–DDRC0
Read/Write
summarizes the operation of the port C pins.
PTCPUEx
PTC1–PTC0
Read
Pin
Pin
Accesses to PTC
V
DD
INTERNAL
PULLUP
DEVICE
PTCx
PTC1–PTC0
PTC1–PTC0
PTC1–PTC0
Write
Port C
(3)
(3)
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