PCI445X

The start frame width may vary from four to eight PCI clock cycles. The STOP frame width is two clock cycles for quiet mode and three clock cycles for continuous mode. Default mode is continuous mode for all slave devices and a host device. PIIX4 does not support IRQ0, IRQ8, and IRQ13. The PCI445X can generate serial IRQ frames for ISA and PCI interrupts. Below are related registers and their definitions.