128Kbit dual-port SRAM with 55 ns access — the shared-memory workhorse
The Cypress CY7C025-55JXC is a 128Kbit asynchronous dual-port SRAM organized as 8K words by 16 bits. Its 55 ns access time suits processor-to-processor mailbox or FIFO-style data exchange where both ports need independent read/write access to the same memory array without arbitration dead cycles.
At 55 ns the part fits into a 12.5 MHz or slower shared-bus window with no wait states, assuming typical address-to-data setup. If your system clock runs faster, the bus controller must insert wait cycles or you trade throughput for timing margin. The write cycle time matches the access time at 55 ns, so back-to-back writes on the same port are possible at that rate — useful for burst transfers from a DMA controller.
Package and footprint: 84-PLCC, J-lead
Housed in an 84-lead PLCC with J-leads (29.31 mm body square), the part is surface-mountable but requires a PLCC socket or reflow profile tuned for the J-lead geometry.
If your application sees ambient below freezing or above 70°C, this part is out of spec.
Lifecycle reality: obsolete, no direct replacement on record
Cypress has marked the CY7C025-55JXC obsolete.