| 摘要 |
<p>PURPOSE:To attain the econimical detection for key input with high accuracy without deteriorating the CPU processing capability, by performing automatically the reading and check of the return data and the transmission of scan data when an interval signal is generated. CONSTITUTION:When an interval signal 310 is produced, an I/O processing request control part 305-2 outputs the addresses of a microservice register group 200 onto an internal bus 108. An execution control part 304 reads out the contents of the group 200 and reads return data from an input port 107. Then the part 304 reads the value of the preceding return data out of a key input buffer 103-1 of an address designated by a pointer BFP200-1 and compares it with the value read out of the port 107. When coincidence is obtained from said comparison, the key input state has no change. Thus the increment is fed to the BFP200- 1, and the scan data is shifted by a bit and transmitted through an output port 106. Thus the economical detection is made possible for key input with high accuracy without deteriorating the CPU processing capability.</p> |
