82091AA Datasheet, PDF (77/204 Pages) Intel Corporation – ADVANCED INTEGRATED PERIPHERAL (AIP)

82091AA
Bit
Description
7 BUSY STATUS (BUSYS) This bit indicates the state of the parallel port interface BUSY signal
When BUSY is asserted BUSYS^e0 When BUSY is negated BUSYS^e1 This is an inverted
version of the parallel port BUSY signal Refer to Section 6 2 3 ECP Mode for more detail
6 ACK STATUS (ACKS) This bit indicates the state of the parallel port interface ACK signal This
bit indicates when the peripheral has received a data byte and is ready for another When ACK is
asserted ACKS^e0 When ACK is negated ACKS^e1 Note that if interrupts are enabled (via bit 4
of the PCON Register) the assertion of the ACK signal generates an interrupt to the CPU Refer to
Section 6 2 3 ECP Mode for more detail
5 PERROR STATUS (PERRS) This bit indicates the state of the parallel port interface PERROR
signal This bit indicates when an error has occurred in the peripheral paper path (e g out of paper)
When PERROR is asserted PERRS^e1 When PERROR is negated PERRS^e0
4 SELECT STATUS (SELS) This bit is used in all parallel port modes and indicates the state of the
parallel port interface SELECT signal When the SELECT signal is asserted SELS^e1 When the
SELECT signal is negated SELS^e0
3 FAULT STATUS (FAULTS) This bit is used in all parallel port modes and indicates the state of
the parallel port interface FAULT signal being driven by the peripheral device When the FAULT
signal is asserted FAULTS^e0 When the FAULT signal is negated FAULTS^e1
2 PARALLEL PORT INTERRUPT (PIRQ) In ECP mode interrupt status is not reported in this register
and this bit is always 1
1 0 RESERVED
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