Input/Output (I/O) Ports
Technical Data
MC68HC908AB32
—
Rev. 1.0
322
Input/Output (I/O) Ports
MOTOROLA
Figure 17-10. Port C I/O Circuit
When DDRCx is a logic 1, reading address $0002 reads the PTCx data
latch. When 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.
summarizes the operation of the port C pins.
Table 17-4. Port C Pin Functions
DDRC
Bit
PTC Bit
I/O Pin Mode
Accesses to DDRC
Accesses to PTC
Read/Write
Read
Write
0
2
Input, Hi-Z
DDRC7
Pin
PTC2
1
2
Output
DDRC7
0
—
0
X
(1)
Notes:
1. X = don’t care; except PTC2.
Input, Hi-Z
(2)
2. Hi-Z = high impedance.
DDRC[5:0]
Pin
PTC[5:0]
(3)
3. Writing affects data register, but does not affect input.
1
X
Output
DDRC[5:0]
PTC[5:0]
PTC[5:0]
READ DDRC ($0006)
WRITE DDRC ($0006)
RESET
WRITE PTC ($0002)
READ PTC ($0002)
PTCx
DDRCx
PTCx
INTERNAL D
AT
A
B
U
S
MCLK
MCLKEN
PTC2 ONLY
Summary of Contents for MC68HC908AB32
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Page 68: ...FLASH Memory Technical Data MC68HC908AB32 Rev 1 0 68 FLASH Memory MOTOROLA ...
Page 84: ...EEPROM Technical Data MC68HC908AB32 Rev 1 0 84 EEPROM MOTOROLA ...
Page 390: ...Ordering Information Technical Data MC68HC908AB32 Rev 1 0 390 Ordering Information MOTOROLA ...
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