Eurotech Appliances CPU-1461 user manual PCI Advanced Page, Isa Irq, Latency Time Devices

PC/104-Plus – CPU-1461 Module 39

PCI Advanced Page

This page can be used to specify some advanced PCI options like:

ƒISA IRQ

ƒLatency Time (both for CPU and devices)

ISA IRQ

This option makes possible any assignment between an ISA IRQ (for the Interrupt Controller) and the four PCI IRQ lines A, B, C and D. Obviously not all the assignments are legal, but the Setup programs shows only the available ISA interrupts.

Option	Description	Note
9	Routes PCI INT_n (n = A, B, C or D) to ISA IRQ 9	The IRQ# can be shared
10	Routes PCI INT_n (n = A, B, C or D) to ISA IRQ 10	The IRQ# can be shared
11	Routes PCI INT_n (n = A, B, C or D) to ISA IRQ 11	The IRQ# can be shared
12	Routes PCI INT_n (n = A, B, C or D) to ISA IRQ 12	The IRQ# can be shared

•Note: the ISA IRQ number can be shared among the PCI IRQ lines A, B, C and D.

Latency Time (Devices)

This Latency Time is the maximum time, expressed in clock cycle unit, that a generic PCI Device (like PCI bus master) can hold the control of the PCI bus. The default value, generally, is 32.

	Option	Description	Note
0..255		Latency time expressed in clock cycle units