Ampro Corporation 486E Parallel Port Interrupt Enable, Register Bit Signal Name In/Out Active J15

Little Board™/486e Technical Manual

Parallel Port Interrupt Enable

Bit 4 in the control register (see Table 2–18) enables the parallel port interrupt. If this bit is high, then a rising edge on the -ACK (IRQ) line produces an interrupt on the interrupt IRQ7 (or IRQ5 if configured as the secondary port). .

Table 2–18. Parallel Port Register Bits

Register	Bit	Signal Name	In/Out	Active	J15	DB25F
		or Function		High/Low	Pin	Pin
DATA	0	Data 0	I/O	High	3	2
(378h)	1	Data 1	I/O	High	5	3
	2	Data 2	I/O	High	7	4
	3	Data 3	I/O	High	9	5
	4	Data 4	I/O	High	11	6
	5	Data 5	I/O	High	13	7
	6	Data 6	I/O	High	15	8
	7	Data 7	I/O	High	17	9
STATUS	0	0	In	---	---	---
(379h)	1	0	---	---	---	---
	2	0	---	---	---	---
	3	-ERROR	In	Low	4	15
	4	SLCT	In	High	25	13
	5	PE	In	High	23	12
	6	-ACK (IRQ)	In	Low	19	10
	7	BUSY	In	High	21	11
CONTROL	0	-STROBE	Out	Low	1	1
(37Ah)	1	-AUTOFD	Out	Low	2	14
	2	-INIT	Out	High	6	16
	3	SLC	Out	High	8	17
	4	IRQE	---	High	---	---
	5	PCD	---	High	---	---
	6	1	---	---	---	---
	7	1	---	---	---	---

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