| 摘要 |
PURPOSE:To prevent malfunction and to reduce software by permitting a microprocessor to detect transition from reproduction mode to stop mode as fast as possible and then causing an interruption corresponding to the transition. CONSTITUTION:The output line 25 of a mode detection part 5 is connected to the clock input terminal CK of a D-FF27 and an input terminal D is placed in a pull-up state. The output line 28 of an address decoder 11 is connected to an AND gate 30 on AND basis with the output line 29 of a power-on resetting circuit 26 and further connected to the clear terminal CLR of the D-FF27 to clear the D-FF27. Then, the inversion output -Q of the D-FF is connected to the interruption input terminal iNT of the microprocessor 10 through an interruption signal line 31. The microprocessor 10, however, starts interruption processing when the interruption input terminal iNT is held at a low level. Thus, malfunction is eliminated and a load on software is reduced greatly. |
