Key stroke detection for keyboard remote wake-up

摘要

A keyboard is placed into a suspend mode. Upon the detection of the pressing of a key, the keyboard processor is wakened from the suspend mode. No power is consumed during the suspend mode, sine the keyboard processor is not scanning the key matrix. The key matrix drive circuitry may also be tested by monitoring a signal emanating from the key matrix drive circuitry and scanning each of the drive lines in the key matrix. If the signal is altered, then the associated drive line in the keyboard drive circuitry is defective. Testing of sense circuitry is performed by changing pull-up resistors to pull-down resistors and then reading sense lines.