Semiconductor integrated circuit equipment with asynchronous operation

摘要

A semiconductor integrated circuit device includes a memory, /CE transition detector, address transition detector, /WE transition detector and controller. The controller includes a timeout circuit. The timeout circuit generates an internal circuit control signal with preset width to control access to the memory based on detection results of the above transition detectors. The operation of the memory is controlled by the timeout circuit at the read time. The operation of the memory is controlled by the timeout circuit when transition of the end of a /WE signal is detected by the /WE transition detector before a timing specified by the timeout circuit at the write time. Further, the operation of the memory is controlled in response to the transition of the /WE signal when the transition of the end of the /WE signal is detected by the /WE transition detector after passage of the above timing.