Asynchronous FIFO for 5 V bus buffering
The CY7C433-20JXC: Asynchronous FIFO, 36 Kbit (4 K x 9), unidirectional, 20 ns access, 50 MHz data rate. Supports depth and width expansion; includes retransmit capability. Maximum supply current is 55 mA.
20 ns access — what it means for bus timing
20 ns access time; 50 MHz data rate.
Retransmit and expansion — what the flags tell you
The CY7C433-20JXC includes a retransmit pin that resets the internal read pointer to the first unread word without clearing the FIFO contents. This is useful in protocol applications where a receiver needs to re-read a corrupted packet after a CRC error. The part does not support programmable flags or FWFT (First-Word Fall-Through) — the empty and full flags are hard-wired to the internal pointer logic. For designs that need flag thresholds, look at the CY7C42x series with programmable almost-empty/almost-full outputs.