LSI 53C875A - Manual (Page 84)

3-8 Signal Descriptions
3.3.6 Interrupt Signal
Table 3.7 describes the Interrupt signal.
3.4 SCSI Bus Interface Signals
The SCSI Bus Interface signals section contains tables describing the
signals for the following signal groups:
SCSI Bus Interface Signals , SCSI
Signals , and SCSI Control Signals .
3.4.1 SCSI Bus Interface Signal
Table 3.8 describes the SCSI Bus Interface signal.
Table 3.7 Interrupt Signal
Name PQFP BGA Type Strength Description
IRQ/ 52 M5 O 8 mA PCI Interrupt Request. This signal, when asserted LOW,
indicates that an interrupting condition has occurred and
that service is required from the host CPU. The output
drive of this pin is open drain.
1. See Register 0x4D, SCSI Test One (STEST1) in Chapter 4 for additional information on this signal.
Table 3.8 SCSI Bus Interface Signal
Name PQFP BGA Type Strength Description
SCLK 56 M6 I N/A SCSI Clock is used to derive all SCSI-related timings. The
speed of this clock is determined by the application’s
requirements. In some applications, SCLK may be sourced
internally from the PCI bus clock (CLK). If SCLK is
internally sourced, then the SCLK pin should be tied low.