MC68HC908GR16 Datasheet, PDF (136/310 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Input/Output Ports (PORTS)
Table 12-3. Port B Pin Functions
DDRB PTB
Bit
Bit
0
X⁽¹⁾
1
X
I/O Pin
Mode
Input, Hi-Z⁽²⁾
Output
Accesses
to DDRB
Read/Write
DDRB7–DDRB0
DDRB7–DDRB0
1. X = Don’t care
2. Hi-Z = High impedance
3. Writing affects data register, but does not affect input.
Accesses
to PTB
Read
Write
Pin
PTB7–PTB0⁽³⁾
PTB7–PTB0
PTB7–PTB0
12.4 Port C
Port C is a 7-bit, general-purpose bidirectional I/O port. Port C also has software
configurable pullup devices if configured as an input port.
12.4.1 Port C Data Register
The port C data register (PTC) contains a data latch for each of the port C pins.
Address: $0002
Bit 7
Read: 0
Write:
6
PTC6
5
PTC5
4
PTC4
3
PTC3
2
PTC2
1
PTC1
Bit 0
PTC0
Reset:
= Unimplemented
Unaffected by reset
R = Reserved
Figure 12-9. Port C Data Register (PTC)
PTC6 and PTC0 — Port C Data Bits
These read/write bits are software-programmable. Data direction of each port C
pin is under the control of the corresponding bit in data direction register C.
Reset has no effect on port C data.
12.4.2 Data Direction Register C
Data direction register C (DDRC) determines whether each port C pin is an input
or an output. Writing a logic 1 to a DDRC bit enables the output buffer for the
corresponding port C pin; a logic 0 disables the output buffer.
Address:
Read:
Write:
Reset:
$0006
Bit 7
0
6
DDRC6
5
DDRC5
4
DDRC4
3
DDRC3
2
DDRC2
1
DDRC1
0
0
0
0
0
0
0
= Unimplemented
Figure 12-10. Data Direction Register C (DDRC)
Bit 0
DDRC0
0
Data Sheet
136
Input/Output Ports (PORTS)
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MC68HC908GR16 — Rev. 1.0
MOTOROLA