Intel mcs-48 manual Mode 0 Port Definition, Mode 0 Configurations

8255A18255A·5

MODE 0 Port Definition

	A	B		GROUPA			GROUPB
04	03	0,	DO	PORTA	PORTC	#	PORTB	PORTC
					(UPPERI			(LOWERI
0	0	0	0	OUTPUT	OUTPUT	0	OUTPUT	OUTPUT
0	0	0	1	OUTPUT	OUTPUT	1	OUTPUT	INPUT
0	0	1	0	OUTPUT	OUTPUT	2	INPUT	OUTPUT
0	0	1	1	OUTPUT	OUTPUT	3	INPUT	INPUT
0	1	0	0	OUTPUT	INPUT	4	OUTPUT	OUTPUT
0	1	0	1	OUTPUT	INPUT	5	OUTPUT	INPUT
0	1	1	0	OUTPUT	INPUT	6	INPUT	OUTPUT
0	1	1	1	OUTPUT	INPUT	7	INPUT	INPUT
1	0	0	0	INPUT	OUTPUT	8	OUTPUT	OUTPUT
1	0	0	1	INPUT	OUTPUT	9	OUTPUT	INPUT
1	0	1	0	INPUT	OUTPUT	10	INPUT	OUTPUT
1	0	1	1	INPUT	OUTPUT	11	INPUT	INPUT
1	1	0	0	INPUT	INPUT	12	OUTPUT	OUTPUT
I	1	0	1	INPUT	INPUT	13	OUTPUT	--
								INPUT
1	1	1	0	INPUT	INPUT	14	INPUT	OUTPUT
1	1	1	1	INPUT	INPUT	15	INPUT	INPUT

MODE 0 Configurations

CONTROL WORD #0

0, D. D, D, D, D, D, D.

I,!o!o!o!o!o! o 1 0 I

A•

8255A

4

°7'°0 . c{

4

PA,-PAc

Pe,·pee

Pe3·peO

CONTROL WORD #2
0,	D. D. D, D, D, D,	Do
I,	1 0 1 0 1 0 1 0 1 0 1 ,	1 0 I
		A	•	PA,.PAo
	8255A
			4	pc,.pee
°,,°0		c{	•	pc3,peO

B

CONTROL WORD #1

0, o. 0, o. 0, 0, 0, Do

B

PII,-P80

8 8 PII,-P8o

CONTROL WORD #3

0, 0, 0, D. 0, 0, 0, Do

I'10 1 o1 0 1 0 1 0 1 o 1 ' I

	A	8
	8255A
	c{ .	4
0,.00		I /.

8•

PA,-PAc

PC7 -PC4

PC3,PCO

PII,.P80

1,10101010101, I, I

		A	8	PA,-PAc
	.	8255A	•
°7'°0 I		c{		Pe"pee
			•	Pc.-pco

8~-PII,.P8o

9-22 AFN-Q07.4A-06