82375EB Datasheet, PDF (24/131 Pages) Intel Corporation – PCI-EISA BRIDGE (PCEB)

82375EB SB
2 6 PCEB ESC Interface Signals
Pin Name Type
Description
ARBITRATION AND INTERRUPT ACKNOWLEDGE CONTROL
EISAHOLD in
EISA HOLD EISAHOLD is used by the ESC to request control of the EISA Bus from
the PCEB This signal is synchronous to PCICLK and is driven inactive when
PCIRST is asserted
EISAHLDA out
EISA HOLD ACKNOWLEDGE The PCEB asserts EISAHLDA to inform the ESC that
it has been granted ownership of the EISA Bus This signal is synchronous to the
PCICLK
PEREQ
INTA
out PCI-TO-EISA REQUEST OR INTERRUPT ACKNOWLEDGE PEREQ INTA is a
dual-function signal The signal function is determined by the state of EISAHLDA
signal
When EISAHLDA is negated this signal is an interrupt acknowledge (i e PEREQ
INTA asserted indicates to the ESC that the current cycle on the EISA is an interrupt
acknowledge)
When EISAHLDA is asserted this signal is a PCI-to-EISA request (i e PEREQ
INTA asserted indicates to the ESC that the PCEB needs to obtain the ownership of
the EISA Bus on behalf of a PCI agent)
This signal is synchronous to the PCICLK and it is driven inactive when PCIRST is
asserted
STPGNT out STOP GRANT ACKNOWLEDGE STPGNT is asserted when the PCEB receives a
STOP GRANT PCI special cycle for one PCICLK period This signal is only asserted
when the PCI AD 31 0 signals equal 00120002h during the first data phase of the PCI
special cycle Data of 00120002h on AD 31 0 in subsequent data phases during a
PCI special cycle does not result in the assertion of STPGNT
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