What the 55 ns access time means for bus timing
The CY7C142-55PC: In a legacy 5 V system, that 55 ns window sets the memory bus cycle ceiling — the address must be stable and the chip enable asserted for at least that long before data appears on the I/O pins. If your board's bus controller runs faster than a 55 ns cycle, this part will miss the data window.
Dual-port architecture — what it does on the board
This is a true dual-port SRAM with two independent address and data buses, allowing two separate controllers (or one controller and a DMA engine) to access the same 2K x 8 memory array simultaneously. The asynchronous interface means no clock is needed — each port's timing is independent, driven by its own chip enable and read/write strobes. On a board that needs shared memory between a main processor and a coprocessor or FPGA, the dual-port eliminates the bus arbitration logic a single-port RAM would require.
Package and board-fit — the 48-PDIP footprint
Housed in a 48-lead PDIP with 0.600-inch (15.24 mm) row spacing, the CY7C142-55PC is a through-hole part intended for socketed or soldered mounting on boards that predate surface-mount memory. The 48-PDIP footprint is standard — the same pattern used by legacy EPROMs and microcontrollers of that era. If you are retrofitting a board that originally used a different dual-port SRAM, verify the pinout against the CY7C142 family datasheet before committing the BOM line.
Lifecycle reality — obsolete, no direct successor
Infineon (formerly Cypress) lists the CY7C142-55PC as obsolete. For a board that already carries this part in the BOM, the only sourcing path is through independent distribution — surplus, new-old-stock, or broker inventory. The 5 V supply and 48-PDIP package limit drop-in replacement options; a functional replacement would likely require a board spin to a different package and voltage domain.
Supply voltage and temperature grade
If the board lives in a conditioned space, the temperature rating is fine; for an unenclosed or outdoor deployment, the part may drift out of spec on the high end.