| 摘要 |
PURPOSE:To set different transfer speeds between font data and other data by delaying a data transfer request to a serial interface control means when the data excluding the font data are transferred. CONSTITUTION:A flip-flop 8 stores a transfer indication of the font data under the control of a direct memory access controller 5 and delivers its output to an AND circuit 9. A data transfer request signal RDY is applied to the circuit 9 from a serial I/O control part 3. The output of the circuit 9 is delayed by a delay circuit 10 and applied to an OR circuit 11, and a terminal count signal TC is applied to the circuit 11. The output of the circuit 11 is delivered to an external status port EXSTS at the part 3.The part 3 transfers data to an output device by a signal WR given from the controller 5 and the CPU1. |
