IS200IVFBG1AAA工控备件模块
这些端口的标准PC使用。表2-2 VMIVME-7750 I/O地址映射（续）BYTES HW DEVICE PC/AT FUNCTION 42中的I/O地址范围大小VMIVME-7720产品手册中断系统中断除I/O端口地址外，I/O设备还具有单独的硬件中断线分配。分配给每个中断线的是内存中$00000至$003FF的256向量中断表中的相应中断向量。表2-3列出了16个可屏蔽中断和单个不可屏蔽中断（NMI）及其功能。第43页的表2-4详细说明了中断向量表中的向量。在第43页的表2-4中，还定义了十六进制和十进制中断数用于实模式和保护模式。VMIVME-7750上的中断硬件实现是围绕PC架构构建的计算机的标准，PC架构是从IBM PC/XT演变而来的。在IBM PC/XT计算机中，仅存在八条中断请求线，在PIC处编号从IRQ0到IRQ7。IBM PC/AT计算机通过将第二个从属PIC级联到原始主PIC中，又增加了八条IRQx线，编号为IRQ8到IRQ15。主PIC处的IRQ2作为从PIC的级联输入。该架构如第47页图2-1所示。为了保持与PC/XT系统的向后兼容性，IBM选择在从属PIC上使用新的IRQ9输入作为PC/XT扩展总线上的旧IRQ2中断线。因此，在AT系统中，IRQ9中断线连接到AT扩展总线（或ISA总线）上的旧IRQ2引脚（引脚B4）。表2-3 PC硬件中断线路分配IRQ AT FUNCTION注释NMI奇偶校验错误（必须在BIOS设置中启用）由VMIVME-7750 PCI总线接口使用0系统计时器由BIOS设置设置1键盘由BIOS设置2双工到IRQ9 3 COM2 4 COM1 5未使用6软盘控制器7未使用8实时时钟9旧IRQ2 SVGA或网络I/O 10未分配由BIOS确定11未分配由BIOS 43确定中断2 12鼠标13数学协处理器14 AT硬盘驱动器15闪存驱动器表2-4 PC中断矢量表Interrupt NO.IRQ LINE REAL MODE PROTECTED MODE HEX DEC 00 0除法错误与实模式01 1调试单步与实模式02 2 NMI内存奇偶校验错误，VME中断与实模式相同（必须在BIOS设置中启用）03 3调试断点与实模式一样04 4 ALU溢出与实模式一致05 5打印屏幕阵列边界检查06 6无效操作码07 7设备不可用08 8检测到IRQ0定时器滴答双重异常09 9 IRQ1键盘输入协处理器段溢出0A 10 IRQ2 BIOS保留无效任务状态段0B 11 IRQ3 COM2串行I/O段不存在0C 12 IRQ4 COM1串行I/O堆栈段超限0D 13 IRQ5未分配未分配0E 14 IRQ6软盘控制器页面故障0F 15 IRQ7未分配未指定10 16 BIOS视频I/O协处理器错误11 17系统配置检查与实模式相同12 18内存大小检查与实模13 19 XT软盘/硬盘驱动器与实模式表2-3 PC硬件中断线作业
standard PC usage of these ports. Table 2-2 VMIVME-7750 I/O Address Map (Continued) I/O ADDRESS RANGE SIZE IN BYTES HW DEVICE PC/AT FUNCTION 42 2 VMIVME-7750 Product Manual Interrupts System Interrupts In addition to an I/O port address, an I/O device has a separate hardware interrupt line assignment. Assigned to each interrupt line is a corresponding interrupt vector in the 256-vector interrupt table at $00000 to $003FF in memory. The 16 maskable interrupts and the single Non-Maskable Interrupt (NMI) are listed in Table 2-3 along with their functions. Table 2-4 on page 43 details the vectors in the interrupt vector table. The interrupt number in HEX and decimal are also defined for real and protected mode in Table 2-4 on page 43. The interrupt hardware implementation on the VMIVME-7750 is standard for computers built around the PC architecture, which evolved from the IBM PC/XT. In the IBM PC/XT computers, only eight interrupt request lines exist, numbered from IRQ0 to IRQ7 at the PIC. The IBM PC/AT computer added eight more IRQx lines, numbered IRQ8 to IRQ15, by cascading a second slave PIC into the original master PIC. IRQ2 at the master PIC was committed as the cascade input from the slave PIC. This architecture is represented in Figure 2-1 on page 47. To maintain backward compatibility with PC/XT systems, IBM chose to use the new IRQ9 input on the slave PIC to operate as the old IRQ2 interrupt line on the PC/XT Expansion Bus. Thus, in AT systems, the IRQ9 interrupt line connects to the old IRQ2 pin (pin B4) on the AT Expansion Bus (or ISA bus). Table 2-3 PC Hardware Interrupt Line Assignments IRQ AT FUNCTION COMMENTS NMI Parity Errors (Must be enabled in BIOS Setup) Used by VMIVME-7750 PCIbus Interface 0 System Timer Set by BIOS Setup 1 Keyboard Set by BIOS Setup 2 Duplexed to IRQ9 3 COM2 4 COM1 5 Unused 6 Floppy Controller 7 Unused 8 Real-Time Clock 9 Old IRQ2 SVGA or Network I/O 10 Not Assigned Determined by BIOS 11 Not Assigned Determined by BIOS 43 Interrupts 2 12 Mouse 13 Math Coprocessor 14 AT Hard Drive 15 Flash Drive Table 2-4 PC Interrupt Vector Table INTERRUPT NO. IRQ LINE REAL MODE PROTECTED MODE HEX DEC 00 0 Divide Error Same as Real Mode 01 1 Debug Single Step Same as Real Mode 02 2 NMI Memory Parity Error, VME Interrupts Same as Real Mode (Must be enabled in BIOS Setup) 03 3 Debug Breakpoint Same as Real Mode 04 4 ALU Overflow Same as Real Mode 05 5 Print Screen Array Bounds Check 06 6 Invalid OpCode 07 7 Device Not Available 08 8 IRQ0 Timer Tick Double Exception Detected 09 9 IRQ1 Keyboard Input Coprocessor Segment Overrun 0A 10 IRQ2 BIOS Reserved Invalid Task State Segment 0B 11 IRQ3 COM2 Serial I/O Segment Not Present 0C 12 IRQ4 COM1 Serial I/O Stack Segment Overrun 0D 13 IRQ5 Unassigned Unassigned 0E 14 IRQ6 Floppy Disk Controller Page Fault 0F 15 IRQ7 Unassigned Unassigned 10 16 BIOS Video I/O Coprocessor Error 11 17 System Configuration Check Same as Real Mode 12 18 Memory Size Check Same as Real Mode 13 19 XT Floppy/Hard Drive Same as Real Mode Table 2-3 PC Hardware Interrupt Line Assignments
