AUTOMATIC CHANNEL SETTING SYSTEM

PURPOSE:To make connection to an EISA bus easy by providing a circuit making it possible to set an interruption channel to a higher-order side EISA bus and a DMA channel from a higher-order side with a program and making output active after waiting the setting. CONSTITUTION:An I/O address decode part 17 outputs a channel selection signal 22 to a DMA channel setting part 30 and an interruption channel signal selecting part 32. An high-order side data bus control part 18 input/output-controls data to a higher-order side data 3 and a lower-order side data bus 35 input/output- controls data to a lower-order side data bus. A DRQ signal selecting part 9 and a DACK signal selecting part 20 selects/outputs DRQ signals 5 to 8 and selects/inputs DACK signals 9 to 12. An interruption signal selecting part 21 controls selection/output to IRQ signals 13 to 16 with an interruption channel selecting signal 27 and an interruption signal selecting signal 28.