What this FIFO is and where it fits
The 57401AW/883B is a 64-word by 4-bit asynchronous FIFO in a 20-lead ceramic flatpack (20-CFlatpack). It buffers data across clock domains or bus-width mismatches where the read and write sides run independently — no common clock needed. The 10 MHz data rate and 65 ns access time suit moderate-speed data acquisition, telemetry, or control-logic handshaking in systems that need a small, fast elastic store. This is a width-expansion FIFO — you cascade multiple devices to increase word width, not depth. No FWFT (First-Word Fall-Through) or programmable flags; the flag logic is basic empty/full with retransmit capability absent. The part is unidirectional: data flows one way.