ABB 70BV01c-ES HESG447260R1输入输出模块
INTx#与CLK异步。当请求设备驱动程序注意时，设备断言其INTx#行。一旦INTx#信号被断言，它将保持断言，直到设备驱动程序清除未决请求。当请求被清除时，设备取消断言其INTx#信号。PCI为单个功能设备定义了一条中断线，为多功能设备或连接器定义了最多四条中断线。对于单功能设备，只能使用INTA#，而其他三条中断线没有意义。第49页图3-1描述了与VMEbus操作和PCI扩展站点相关的VMIVME-7740中断逻辑。多功能设备上的任何功能都可以连接到任何INTx#线。中断引脚寄存器定义函数用于请求中断的INTx#行。如果设备实现单个INTx#线，则称为INTA#；如果它实现两条线，则称为INTA#和INTB#；等等对于多功能设备，所有功能都可以使用相同的INTx#线，或者每个功能都有自己的（最多四个功能）或其任意组合。
INTx#, is asynchronous to CLK. A device asserts its INTx# line when requesting attention from its device driver. Once the INTx# signal is asserted, it remains asserted until the device driver clears the pending request. When the request is cleared, the device de-asserts its INTx# signal. PCI defines one interrupt line for a single function device and up to four interrupt lines for a multifunction device or connector. For a single function device, only INTA# may be used while the other three interrupt lines have no meaning. Figure 3-1 on page 49 depicts the VMIVME-7740 interrupt logic pertaining to VMEbus operations and the PCI expansion site. Any function on a multifunction device can be connected to any of the INTx# lines. The Interrupt Pin register defines which INTx# line the function uses to request an interrupt. If a device implements a single INTx# line, it is called INTA#; if it implements two lines, they are called INTA# and INTB#; and so forth. For a multifunction device, all functions may use the same INTx# line or each may have its own (up to a maximum of four functions) or any combination thereof.
