MC68HC908JL3E Datasheet, PDF (160/226 Pages) Motorola, Inc – Microcontrollers

Input/Output (I/O) Ports
ADC[7:0] — ADC channels 7 to 0
ADC[7:0] are pins used for the input channels to the analog-to-digital
converter module. The channel select bits, ADCH[4:0], in the ADC
status and control register define which port pin will be used as an
ADC input and overrides any control from the port I/O logic. See
Section 11. Analog-to-Digital Converter (ADC).
12.4.2 Data Direction Register B (DDRB)
Data direction register B determines whether each port B pin is an input
or an output. Writing a logic one to a DDRB bit enables the output buffer
for the corresponding port B pin; a logic zero disables the output buffer.
Address: $0005
Bit 7
6
5
4
3
2
1
Read:
DDRB7 DDRB6 DDRB5 DDRB4 DDRB3 DDRB2 DDRB1
Write:
Reset: 0
0
0
0
0
0
0
Figure 12-7. Data Direction Register B (DDRB)
Bit 0
DDRB0
0
DDRB[7:0] — Data Direction Register B Bits
These read/write bits control port B data direction. Reset clears
DDRB[7:0], configuring all port B pins as inputs.
1 = Corresponding port B pin configured as output
0 = Corresponding port B pin configured as input
NOTE:
Avoid glitches on port B pins by writing to the port B data register before
changing data direction register B bits from 0 to 1. Figure 12-8 shows
the port B I/O logic.
Technical Data
160
MC68H(R)C908JL3E/JK3E/JK1E — Rev. 2.0
Input/Output (I/O) Ports
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