| 摘要 |
PURPOSE:To reduce the average current consumption of a microcomputer by increasing the operation frequency of the computer in accordance with the detection of a card, reading card data, and at the completion of the reading, decreasing the operation frequency. CONSTITUTION:The microcomputer 6 is usually actuated by low clock oscillation frequency determined by a capacitor 7 and resistors 8, 9. When a magnetic card 3 is inserted and a card detecting switch 1 is closed, the microcomputer 6 judges the insertion of the card into a reading position and outputs a signal for closing an analog switch 10 from a P0 port and the clock oscillation frequency is switched to high frequency by the capacitor 7 and the resistor 8. When the clock frequency is increased, digital information on the magnetic card is inputted to the K3 port of the computer 6 sequentially to read the information. When the necessary volume of information is read into the computer 6, the computer 6 outputs a signal for opening the analog switch 10 again and the clock oscillation frequency is switched to the low value. |
