| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power management technique for realizing recovery from an electrostatic discharge latchup event for a fingerprint sensor system. <P>SOLUTION: A power management unit monitors current drawn by a fingerprint sensor circuit and generates a 'heartbeat' signal during normal operation. When the latchup event occurs, with attendant increase in current drawn by the fingerprint sensor circuitry, the heartbeat signal terminates and an interrupt is subsequently triggered to start a latchup recovery routine. Power to the fingerprint sensor circuitry is switched off and the interrupt is then cleared by writing appropriate values to control bits within the power management register. <P>COPYRIGHT: (C)2003,JPO |
