Dual-port SRAM for shared-memory designs
The Infineon CY7C0251E-15AXC is a 144 Kbit dual-port asynchronous SRAM organized as 8K x 18 bits. Its defining feature is two independent address, data, and control buses that allow two separate bus masters — two processors, a processor and an FPGA, or a processor and a DMA controller — to access the same memory array simultaneously without arbitration logic. The 15 ns access time means each port can complete a read or write cycle in 15 ns, keeping pace with fast asynchronous buses in the 66 MHz range without inserting wait states.
15 ns access time — timing margin on the bus
In a dual-port system, both ports share the same memory array, so the worst-case arbitration delay (when both ports hit the same address) adds to the access time. The 15 ns spec is the port's own access time assuming no contention; the actual bus turnaround budget must account for the arbitration logic's internal delay, typically another 5 ns to 10 ns. If your bus cycle time is 25 ns (40 MHz), you have about 10 ns of margin after arbitration — comfortable for a clean PCB layout with short traces, but tight if the bus runs through a backplane or cable.
Infineon (formerly Cypress) no longer manufactures the CY7C0251E-15AXC as a standard catalog product.
Package and temperature grade — 100-TQFP, commercial range
The CY7C0251E-15AXC is supplied in a 100-lead LQFP with a body size of 14 mm x 14 mm. The package is surface-mount, suitable for standard reflow soldering. For extended-temperature or automotive environments, look for an industrial-grade variant (e.g., CY7C0251E-15AXI) if available.