MC68HC908AZ60 Datasheet, PDF (316/480 Pages) Motorola, Inc – HCMOS Microcontroller Unit

I/O Ports
READ DDRC ($0006)
WRITE DDRC ($0006)
RESET
WRITE PTC ($0002)
DDRCx
PTCx
PTCx
READ PTC ($0002)
Figure 10. 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 3 summarizes the
operation of the port C pins.
Table 3. Port C Pin Functions
Bit
Value
PTC
Bit
I/O Pin
Mode
Accesses
to DDRC
Read/Write
Accesses to PTC
Read
Write
0
2
Input, Hi-Z DDRC[2]
Pin
PTC2
1
2
Output
DDRC[2]
0
—
0
X
Input, Hi-Z DDRC[5:0]
Pin
PTC[5:0]⁽¹⁾
1
X
Output DDRC[5:0] PTC[5:0] PTC[5:0]
X = don’t care
Hi-Z = high impedance
1. Writing affects data register, but does not affect input.
MC68HC908AZ60 — Rev 2.0
314
I/O Ports
10-io
MOTOROLA