SECTION 3
PCI 9080
FUNCTIONAL DESCRIPTION
PLX Technology, Inc., 1997
Page 35
Version 1.02
3.12 INTERRUPTS
LINTo#
DMA Ch 0 Done
DMA Ch 1 Done
Doorbells
Mailboxes
BIST
Messaging Queue
X9
X4
[17]
[7]
[23]
X2
OR
X3
X8
X6
OR
X7
OR
DMA Ch 1
Terminal Count
LSERR#
Master Abort
256 Retrys
Target Abort
Parity Error
Messaging Queue
Doorbells
Master Abort
256 Retrys
Target Abort
LINTi#
Messaging Queue
[1]
[0]
X1
OR
[12]
OR
[9]
[10]
[11]
OR
[12]
OR
X5
INTA#
DMA Ch 0 Done
DMA Ch 0
Terminal Count
X4
X2
OR
X3
DMA Ch 1 Done
X8
X6
OR
X7
DMA Ch 1
Terminal Count
DMA Ch 0
Terminal Count
[8]
[16]
The # represent the bit # of register (LOC [E8h])
X1 = Bits [7:6] of register (LOC [168h])
X2 = Bit 10 of register (LOC [100h])
X3 = Bit 2 of register (LOC [E110h])
X4 = Bit 18 of register (LOC [E8h]) & Bit 17 of register (LOC [100h])
X5 = Bits [5:4] of register (LOC [168h])
X6 = Bit 10 of register (LOC [114h])
X7 = Bit 2 of register (LOC [124h])
X8 = Bit 19 of register (LOC [E8h]) and Bit 17 of register (LOC [114h])
X9 = Bit 3 of register (LOC [B0h]) & Bit 3 of register (LOC [B4h])
For X4 and X8, if bit 17='0', then LINTo# is generated and
if bit 17='1', then INTA# is generated.
Figure 3-21. Interrupt and Error Sources
3.12.1 PCI Interrupts (INTA#)
A PCI 9080 PCI Interrupt (INTA#) can be generated by
one of the following:
Local to PCI Doorbell Register
Local interrupt input
Master/target abort status condition
DMA Ch 0/Ch 1 Done
DMA Ch 0/Ch 1 Terminal Count reached
Messaging Outbound Post Queue not empty
INTA#, or individual sources of an interrupt, can be
enabled or disabled with the PCI 9080 Interrupt
Control/Status Register (refer to Table 4-58). This
register also provides interrupt status for each interrupt
source.
PCI 9080 PCI bus interrupt is level output. An interrupt
can be cleared by disabling an interrupt enable bit or
clearing the cause(s) of the interrupt.
3.12.1.1 Local Interrupt Input
Asserting local bus input pin LINTi# can generate a PCI
bus interrupt. PCI host processor can read PCI 9080
Interrupt Control/Status Register to determine that an
interrupt is pending due to the LINTi# pin being asserted.
The interrupt remains asserted as long as the LINTi# pin
is asserted and the Local Interrupt input is enabled.
Adapter specific action can be taken by the PCI host
processor to cause the local bus to release LINTi#.
3.12.1.2 Master/Target Abort Interrupt
PCI 9080 sets the master abort or target abort status bit
in the PCI configuration register when it detects a master
or target abort. These status bits cause PCI INTA# to be
asserted if interrupts are enabled.
The interrupt remains asserted as long as the master or
target abort bits remain set in the PCI Status
configuration register (refer to Table 4-12) and
master/target abort interrupt is enabled. Use a PCI Type
0 configuration access or a local access to clear the