Irq And Resource Isa Routing Register - VersaLogic EBX-22 Reference Manual

IRQ and Resource ISA Routing Register

IRQISA (Read/Write) 1DEh
D7
COM2 COM1
This register is used to allow IRQs to be routed across the ISA bridge.
Bit Mnemonic
D7 COM2
D6 COM1
D5 COM4
D4 COM3
D3 IRQ10
D2 IRQ5
D1 IRQ4
D0 IRQ3
EBX-22 Reference Manual
D6 D5 D4
COM4 COM3
Table 43: IRQISA Register Bit Assignments
Description
COM2 I/O
0 = I/O range for COM2 is used for on-board UART
1 = I/O range for COM2 is forwarded to ISA bus for use by expansion cards
COM1 I/O
0 = I/O range for COM1 is used for on-board UART
1 = I/O range for COM1 is forwarded to ISA bus for use by expansion cards
COM4 I/O
0 = I/O range for COM4 is used for on-board UART
1 = I/O range for COM4 is forwarded to ISA bus for use by expansion cards
COM3 I/O
0 = I/O range for COM3 is used for on-board UART
1 = I/O range for COM3 is forwarded to ISA bus for use by expansion cards
IRQ10
0 = IRQ10 on PC/104 (ISA) bus is ignored
1 = ISA bridge forwards IRQ10 to host
IRQ5
0 = IRQ5 on PC/104 (ISA) bus is ignored
1 = ISA bridge forwards IRQ5 to host
IRQ4
0 = IRQ4 on PC/104 (ISA) bus is ignored
1 = ISA bridge forwards IRQ4 to host
IRQ3
0 = IRQ3 on PC/104 (ISA) bus is ignored
1 = ISA bridge forwards IRQ3 to host
D3 D2 D1
IRQ10 IRQ5 IRQ4
Special Registers
D0
IRQ3
75