Sram memory, what is Asynchronous sram, SRAM in microcontroller

 CY62136FV30 Series 2 Mb (128 K x 16) 45 ns SMT Static RAM - TSOP II-44

https://www.futureelectronics.com/p/semiconductors--memory--RAM--static-ram--asynchronous/cy62136fv30ll-45zsxit-cypress-4030764