Address transition detector for programmable logic array

摘要

An improved address transition detector for use in PAL circuits is disclosed. The invention provides a predetermined logical output on a transition detection signal (TDS) bus for a transition of the input address on an input pad of the PAL. The TDS bus is used to trigger a phi generator which controls sense amplifiers and latch blocks on the PAL such that the circuitry is maintained in a low power stand-by mode. The detector includes a first inverter for buffering the address input to provide a first signal, a second inverter for inverting the first signal to provide a second signal and a comparator for providing the predetermined logical level on the TDS bus for a period of time after the first signal and the second signal have changed states.