| 摘要 |
<p>PURPOSE:To enable a programmable wait function to apply other I/O devices without adding hardware to other I/O devices, by using a wait display circuit. CONSTITUTION:A microprocessor wait terminal 4 is provided together with an external wait input buffer 2, an OR gate 1 which secures an OR between a programmable wait signal A and an external wait signal, and a transfer gate 3 which outputs the programmable wait signal to outside. A pull-up resistance 5 and an external wait buffer 6 are connected to the terminal 4. A coprocessor contains a coprocessor wait terminal 7 and an input buffer 8. In such a constitution, a wait display circuit outputs a ready signal to the outside of a microprocessor during the bus wait time set by a program. Thus it is possible to apply the programmable wait function of the microprocessor without adding any hardware like a register, etc., to other I/O devices (coprocessors).</p> |
