The CY7C135 and CY7C1342 are high-speed CMOS 4K x 8 dual-port static RAMs. The CY7C1342 includes semaphores that provide a means to allocate portions of the dual-port RAM or any shared resource. Two ports are provided permitting independent, asynchronous access for reads and writes to any location in memory. Application areas include interprocessor/multiprocessor designs, communications status buffering, and dual-port video/graphics memory. Each port has independent control pins: chip enable (CE), read or write enable (R/W), and output enable (OE). The CY7C135 is suited for those systems that do not require on-chip arbitration or are intolerant of wait states. Therefore, the user must be aware that simultaneous access to a location is possible. Semaphores are offered on the CY7C1342 to assist in arbitrating between ports. The semaphore logic is comprised of eight shared latches. Only one side can control the latch (semaphore) at any time. Control of a semaphore indicates that a shared resource is in use. An automatic power-down feature is controlled independently on each port by a chip enable (CE) pin or SEM pin (CY7C1342 only). The CY7C135 and CY7C1342 are available in 52-pin PLCC.