BENTLY 3500/61 I/O模塊
BIOS定義每個(gè)設(shè)備要使用的PC/AT中斷線。BIOS向兩個(gè)級(jí)聯(lián)的8259A PIC芯片中的每一個(gè)寫入一個(gè)8位矢量，該矢量將每個(gè)IRQx映射到存儲(chǔ)器中相應(yīng)的中斷矢量。ISA設(shè)備中斷映射VMIVME-7740 BIOS根據(jù)標(biāo)準(zhǔn)ISA架構(gòu)將IRQx線映射到適當(dāng)?shù)脑O(shè)備。參考第121頁圖E-2。無法更改此初始化操作；然而，自定義應(yīng)用程序可以在BIOS完成初始配置周期后重新路由中斷配置。PCI設(shè)備中斷映射基于PCI總線的外部設(shè)備包括兩個(gè)PCI擴(kuò)展站點(diǎn)、PCI到VMEbus橋和VGA保留連接。默認(rèn)BIOS將這些外部設(shè)備映射到PIIX4E的PCI中斷請(qǐng)求（PIRQx）行。該映射如第121頁圖E-2所示，并在表E-3中定義。無法修改每個(gè)設(shè)備上存在的設(shè)備PCI中斷線（INTA到INTD）。
The BIOS defines the PC/AT interrupt line to be used by each device. The BIOS writes to each of the two cascaded 8259A PIC chips an 8-bit vector, which maps each IRQx to its corresponding interrupt vector in memory. ISA Device Interrupt Map The VMIVME-7740 BIOS maps the IRQx lines to the appropriate device per the standard ISA architecture. Reference Figure E-2 on page 121. This initialization operation cannot be changed; however, a custom application could reroute the interrupt configuration after the BIOS has completed the initial configuration cycle.PCI Device Interrupt Map The PCI bus-based external devices include the two PCI expansion sites, the PCI-to-VMEbus bridge, and the VGA reserved connection. The default BIOS maps these external devices to the PCI Interrupt Request (PIRQx) lines of the PIIX4E. This mapping is illustrated in Figure E-2 on page 121 and is defined in Table E-3. The device PCI interrupt lines (INTA through INTD) that are present on each device cannot be modified.
