VT82C686B
Plug and Play Control
Offset 50 – PNP DMA Request Control..........................RW
Offset 58 – External APIC IRQ Output Control ........... RW
.............................................. default = 0
........................................always reads 0
ACPI IRQ to APIC[23:16] with Rx42[2:0]
7-4 Reserved
7-5 Reserved
.....def = DRQ3
3-2 PnP Routing for Parallel Port DRQ
4
3
2
1
0
0
Disable................................................... default
...............def = DRQ2
1-0 PnP Routing for Floppy DRQ
1
Enable
DRQ Mapping: 00=DRQ0, 01=DRQ1, 10=DRQ2, 11=DRQ3
MC97 IRQ to APIC[23:16] with Rx3C[2:0]
Offset 51 - PNP IRQ Routing 1........................................RW
0
Disable................................................... default
(see PnP IRQ
7-4 PnP Routing for Parallel Port IRQ
1
Enable
routing table)
AC97 IRQ to APIC[23:16] with Rx3C[2:0]
(see PnP IRQ routing
3-0 PnP Routing for Floppy IRQ
0
Disable................................................... default
table)
1
Enable
USB Port 1 IRQ to APIC[23:16] with Rx3C[2:0]
Offset 52 - PNP IRQ Routing 2........................................RW
0
Disable................................................... default
(see PnP IRQ
7-4 PnP Routing for Serial Port 2 IRQ
routing table)
1
Enable
USB Port 0 IRQ to APIC[23:16] with Rx3C[2:0]
(see PnP IRQ
3-0 PnP Routing for Serial Port 1 IRQ
routing table)
0
Disable................................................... default
1
Enable
Offset 54 - PCI IRQ Edge / Level Select..........................RW
........................................ always reads 0
The following bits all default to “level” triggered (0)
7-4 Reserved
.......(1/0)
.......(1/0)
.......(1/0)
.......(1/0)
3
2
1
0
PIRQA# Invert (edge) / Non-invert (level)
PIRQB# Invert (edge) / Non-invert (level)
PIRQC# Invert (edge) / Non-invert (level)
PIRQD# Invert (edge) / Non-invert (level)
Note: PIRQA-D# normally connect to PCI interrupt pins
INTA-D# (see pin definitions for more information).
Offset 55 - PNP IRQ Routing 4........................................RW
(see PnP IRQ routing table)
7-4 PIRQA# Routing
........................................ always reads 0
Offset 56 - PNP IRQ Routing 5........................................RW
3-0 Reserved
(see PnP IRQ routing table)
(see PnP IRQ routing table)
7-4 PIRQC# Routing
3-0 PIRQB# Routing
Offset 57 - PNP IRQ Routing 6........................................RW
(see PnP IRQ routing table)
7-4 PIRQD# Routing
........................................ always reads 0
3-0 Reserved
PnP IRQ Routing Table
0000 Disable ...................................................default
0001 IRQ1
0010 Reserved
0011 IRQ3
0100 IRQ4
0101 IRQ5
0110 IRQ6
0111 IRQ7
1000 Reserved
1001 IRQ9
1010 IRQ10
1011 IRQ11
1100 IRQ12
1101 Reserved
1110 IRQ14
1111 IRQ15
Revision 1.71 June 9, 2000
-59-
Function 0 Registers - PCI to ISA Bridge
ETC [ ETC ]
