W921E840A Datasheet, PDF (18/58 Pages) Winbond – 4-BIT MICROCONTROLLER

W921E840A/W921C840
• P4.0 to P4.3: Multi-function I/O pins (selected by P4IO register)
− Normal function I/O pins
− Special function input pins
P4IO register: (address = 010H, default data = 0H)
b3
b2
b1
b0
0: Normal I/O P4.0, interrupt disable
1: Interrupt port P4.0
0: Normal I/O P4.1, interrupt disable
1: Interrupt port P4.1
0: Normal I/O P4.2, interrupt disable
1: Interrupt port P4.2
0: Normal I/O P4.3, interrupt disable
1: INT0
• P5.0 to P5.3: Multi-function I/O pins (selected by P5IO register)
− Normal function I/O pins
− Special function I/O pins
P5IO register: (address = 011H, default data = 0H)
b3
b2
b1
b0
0: Normal I/O P5.0
1: Work as the timer 1 control pin
0: Normal I/O P5.1
1: Work as the timer 2 control pin
0: Normal I/O P5.2
1: Work as the Vref input pin of the comparator
0: Normal I/O P5.3
1: Work as the output pin of D/A converter
(DAOUT)
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