Abort; Scsi Bus Reset; Ac Fail; System Fail - Performance Computer PT-VME151A User Manual

3
Section FUNCTIONAL DESCRIPTION

General Purpose Local Interrupts

40 Extensible Single Board Computer/Controller User's Manual
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
four external signals are labeled L7I0(NMI) [-INTP<6>], L7I1(MEM) [-INTP<7>], L7I2(ACF)
[-INTP<8>], and L7I3(SYF) [- INTP<9>], respectively. For detailed information on the opera-
tion of the Level 7 interrupt mechanisms and the BI-mode signal refer to the AVICS Technical
Manual.

Abort

Pressing the ABORT button on the front panel will generate a non-maskable interrupt to
the 68040. This interrupt request cannot be disabled. This input is edge sensitive and can
be reset by writing a zero to control bit NMIIE in ACC Level 7 Interrupt Status Register.
The current state of this signal can be read in the NMIIP status bit of the ACC Status
Register 0.

SCSI Bus Reset

When a RESET condition [RST] occurs on the SCSIbus a L7IMEM interrupt is generated
in the ACC. The interrupt is enabled by setting the MEMIS bit in the ACC Level 7 Interrupt
Status Register. The SCSI RESET condition is used to immediately clear all SCSI devices
from the bus. The current state of this signal can be read in the MEMIP status bit of the
ACC Status Register 0.
An L7IMEM interrrupt is also generated if a parity error occurs during a SCSI DMA cycles
or DARF64 local bus master cycles. System Status Register 2 must be read to detrmine the
source of the interrupt. See "Parity" on page 30 for more information.

AC Fail

If the VMEbus [ACFAIL*] signal is asserted an interrupt can be generated to the 68040.
The AC Failure warning allows the PT-VME151A software to execute appropriate shut-
down procedures. The interrupt is enabled by setting the ACFIS bit in the ACC Level 7
Interrupt Status Register. The current state of this signal can be read in the ACFIP status bit
of the ACC Status Register 0.

System Fail

If the VMEbus [SYSFAIL*] signal is asserted an interrupt can be generated to the 68040.
SYSFAIL is typically used by a board to indicate to the system that it has detected a cata-
strophic error. Software can then execute the appropriate recovery procedures. The inter-
rupt is enabled by setting the SYFIS bit in the ACC Level 7 Interrupt Status Register. The
current state of this signal can be read in the SYFIP status bit of the ACC Status Register 0.
The six General Purpose Local Interrupts [-INTP<5-0>] can be mapped to any of the seven CPU
interrupt request levels. Each have their own enable and status bits. On the schematics ACC
symbol, the six external signals are labeled -LIRQ5 through -LIRQ0.
General Purpose Local Interrupts 3 through 0 [-INTP<3-0>] are "auto-vector" only to the
68040. The AVICS allows General Purpose Local Interrupts 5 and 4 [-INTP<5-4>] to be
configured as "vectored" or "auto-vectored" to the 68040. The PT-VME151A/151AE hardware
implementation requires that General Purpose Local Interrupts 5 and 4 always be configured as