mc68hc908gr8vp Freescale Semiconductor, Inc, mc68hc908gr8vp Datasheet - Page 151

• Manufacturer Part Number: mc68hc908gr8vp
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

DDRC1–DDRC0 — Data Direction Register C Bits
Figure 16-11
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
PTCPUE Bit
These read/write bits control port C data direction. Reset clears DDRC1–DDRC0, configuring all port
C pins as inputs.
Notes:
1 = Corresponding port C pin configured as output
0 = Corresponding port C pin configured as input
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
X
1
0
shows the port C I/O logic.
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.
For those devices packaged in a 28-pin DIP and SOIC package, PTC1,0
are not connected. Set DDRC1,0 to a 1 to configure PTC1,0 as outputs.
DDRC Bit
0
0
1
READ DDRC ($0006)
WRITE DDRC ($0006)
WRITE PTC ($0002)
READ PTC ($0002)
DD
MC68HC908GR8 • MC68HC908GR4 Data Sheet, Rev. 7
by internal pullup device.
PTC Bit
X
X
X
(1)
Table 16-4. Port C Pin Functions
RESET
Figure 16-11. Port C I/O Circuit
I/O Pin Mode
Input, Hi-Z
Input, V
Output
DD
Table 16-4
(4)
(2)
NOTE
NOTE
DDRCx
PTCx
Accesses to DDRC
DDRC1–DDRC0
DDRC1–DDRC0
DDRC1–DDRC0
summarizes the operation of the port C pins.
Read/Write
PTCPUEx
PTC1–PTC0
Read
Pin
Pin
V
Accesses to PTC
DD
INTERNAL
PULLUP
DEVICE
PTCx
PTC1–PTC0
PTC1–PTC0
PTC1–PTC0
Write
Port C
(3)
(3)
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