15 ns asynchronous SRAM for 3.3 V buses
The parallel interface and 15 ns write cycle time let it keep pace with a moderately fast microcontroller without wait states, provided the board layout keeps trace lengths short and decoupling tight.
Obsolete — last-time-buy and sourcing path
The 44-TSOP II footprint is common across the CY7C1021 family, so a pin-compatible drop-in from the same base product number may still be available in active variants — but the -15ZXIT suffix (3.3 V, 15 ns, industrial temp, Tape & Reel) is the specific configuration that is now end-of-life. Any remaining stock is finite; a last-time-buy window has already closed, so the buyer should qualify the BOM against a current-production alternative or secure a bridge lot through the broker channel.
64K x 16 organization and 15 ns timing
The 64K x 16 memory organization gives a 16-bit data bus in a single chip, which simplifies the memory interface for a 16-bit microcontroller or a 32-bit CPU running in 16-bit mode.