DMA CONTROL SIGNAL GENERATING CIRCUITS

摘要

PURPOSE: A circuit for generating a control signal of a direct memory access is provided to decrease a chip size and a cost by discriminating a parameter register setup and an operation of the direct memory access through only one flip-flop. CONSTITUTION: A D flip-flop(30) receives a reset signal(RESET) of an one-chip controller as a clear signal, and outputs a non-inversion value by receiving a chip selection signal(PCS) as a clock input. An inverter(31) inverts an output(Q) of the D flip-flop(30). An NAND gate(32) outputs a result of a logic operation to an DMA(Direct Memory Access) control signal terminal(DACK) by receiving an output of the inverter(31) and a data request signal(DRQ). An inverter(33) outputs a result of the inversion to a chip selection terminal(CS) by inverting an output of the NAND gate(32).