| 摘要 |
PURPOSE:To improve the efficiency of a program and to reduce the capacity of a memory by interrupting a microprocessor and causing a microcomputer to read in key data, only when key input exists. CONSTITUTION:When any of keys Z11-Z34 is depressed, the output of an AND circuit 10 goes to the low level, and a flip flop 11 is preset, and an output Q of the flip flop 11 is switched from the high level to the low level, and a key input detection interrupt signal is generated by a short pulse generating circuit 13, and simultaneously, row data and column data are latched in latch circuits 14-17, and the microprocessor reads in row and column data. The output of a decoder 4 which generates column data and the input of an encoder 9 which detects row data are latched in latch circuits 14-17 by the key input interrupt signal.
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