mc68hc908mr24 Freescale Semiconductor, Inc, mc68hc908mr24 Datasheet - Page 326

• Manufacturer Part Number: mc68hc908mr24
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports
15.4 Port B
15.4.1 Port B Data Register
15.4.2 Data Direction Register B
Advance Information
326
Address:
Address:
Port B is an 8-bit, general-purpose, bidirectional I/O port that shares its
pins with the analog-to-digital convertor (ADC) module.
The port B data register (PTB) contains a data latch for each of the eight
port B pins.
PTB[7:0] — Port B Data Bits
Data direction register B (DDRB) determines whether each port B pin is
an input or an output. Writing a logic 1 to a DDRB bit enables the output
buffer for the corresponding port B pin; a logic 0 disables the output
buffer.
Reset:
Reset:
Read:
Read:
Write:
Write:
These read/write bits are software-programmable. Data direction of
each port B pin is under the control of the corresponding bit in data
direction register B. Reset has no effect on port B data.
DDRB7
$0001
$0005
PTB7
Bit 7
Bit 7
0
Figure 15-6. Data Direction Register B (DDRB)
Figure 15-5. Port B Data Register (PTB)
Input/Output (I/O) Ports
DDRB6
PTB6
6
6
0
DDRB5
PTB5
5
5
0
Unaffected by reset
DDRB4
PTB4
4
4
0
DDRB3
PTB3
3
3
0
MC68HC908MR24
DDRB2
PTB2
Freescale Semiconductor
2
2
0
DDRB1
PTB1
1
1
0
—
Rev. 4.1
DDRB0
PTB0
Bit 0
Bit 0
0