Intel mcs-48 manual OJNTl, R,-r-- I-i-Ioo r,-r,-r, Operation Command Word Format

8259A

ocw,

~ 07 ~ ~ ~ ~ ~ 0, ~

I 0	R ISEor IEOI I o i 0 1 c, 1 c, 1 c,	I
			BCD LEVel TO BE RESET
		OR PUT INTO LOWEST PRIORITV
	I	0	,	2	,	.•		6	7
		0	,	0	,	0	,	0	,
		0	0	,	,	0	0	,	,
		0	0	0	0	,	,	,	,

1 r

J- r+

~-'i-r+

r,-o~

I-i-r,-r-;- I-i-Io'o r,-r,-r,-

f7r-;-~

tttttt

NON-$I'ECIFrCEO.

SPECIFIC eol. lO-L2 CODE OF IS Ff TO BE RESET

ROTATE AT Eor AUTOMATICALLY (MODE A)

ROTATE AT EOIIMOOE BI, (LG-U OEFINES NEW LOWESTPRIORITV)

SET ROTATE A FF

CLEAR ROTATE A fF

AOTATE PRIORITY (MODE B) INDEPENDENTLY OF EOI (LO-U CODE OF LINE)

NOOPERATLON

ocw,

I 0 1 - I"M"I SMM 1 0 1 ' 1 p 1ERIS 1 R'S I

OJN'Tl_

CAR~

	READ IN SERVICE REGISTER
0	I	,	0	,
0	I	0	,	,
			READ	REAO
	NO ACTION		IR REG	ISREG
			ON NE'(T	ON NEXT
			RD PULSE	AD PULSE

POLLING

A HIGH ENABLES THE NEXT Fib PULSE TO READ THE BCD CODe OF THE HIGH EST LEVEL REQUESTING INTERRUPT

	SPECIAL MASK MODe
0	1 ,	0	,
0	I 0	,	,
	NO ACTION	RESET	SET
		SPECIAL	SPECIAL
		MA""	MASK

Operation Command Word Format

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