Dual-port SRAM for shared-memory handshaking
The Cypress CY7C136A-55NXI is a 16 Kbit dual-port asynchronous SRAM organized as 2K x 8, intended for shared-memory applications where two independent processors or controllers need to exchange data without bus contention. The dual-port architecture provides two separate address, data, and control ports, each with its own chip enable and output enable, allowing simultaneous reads and writes to different memory locations.
55 ns access time — bus timing margin
For a processor running at 20 MHz (50 ns cycle), this part leaves only 5 ns of margin before the next clock edge — tight enough that the board designer should verify setup/hold timing against the processor's memory controller. If the system bus runs slower (e.g., 10 MHz), the margin is comfortable.
Cypress Semiconductor has designated the CY7C136A-55NXI as obsolete. Buyers should verify date code freshness and RoHS compliance (the 'XI' suffix indicates a lead-free, RoHS-compliant finish) when ordering from surplus inventory.
Package and footprint — 52-BQFP (PQFP)
Supplied in a 52-lead BQFP (bumpered quad flat pack) with a 10x10 mm body, the CY7C136A-55NXI is a surface-mount device. The shipping medium is tray. For PCB layout, the 0.65 mm pitch requires a fine-pitch soldering process; a solder paste stencil with 0.12 mm thickness is typical for this lead pitch.