| 摘要 |
PURPOSE:To detect securely the temporary variation of a status signal outputted from a disk driver by generating an interruption signal to a CPU on the basis of the variation of the status signal to a latch means. CONSTITUTION:When the status signal READY from the disk driver is at a level L indicating a ready state, the output QFF of an FF1 is held at the level L. When the signal READY changes to a level H temporarily, a AND gate G1 generates an H-level output and the FF1 is inverted in synchronism with a clock E, so that the output QFF changes from L to H. Consequently, an inverter INV2 supplies an interruption request signal IRQ to a CPU, which holds a read signal at H so as to read the contents of the FF1. Consequently, a read out control signal CS' changes from H to L and a buffer BFF is opened to supply the output QFF of the FF1 to the CPU as a status signal RD indicating that the status signal READY enters a not ready state, so that the CPU detects that. |
