Functional Description
The CY7C42X1 are high-speed, low-power FIFO memories with clocked Read and Write interfaces. All are 9 bits wide. The CY7C42X1 are pin-compatible to IDT722X1. Programmable features include Almost Full/Almost Empty flags. These FIFOs provide solutions for a wide variety of data buffering needs, including high-speed data acquisition, multiprocessor interfaces, and communications buffering.

FEATUREs
• High-speed, low-power, First-In, First-Out (FIFO) memories
   — 64 × 9 (CY7C4421)
   — 256 × 9 (CY7C4201)
   — 512 × 9 (CY7C4211)
   — 1K × 9 (CY7C4221)
   — 2K × 9 (CY7C4231)
   — 4K × 9 (CY7C4241)
   — 8K × 9 (CY7C4251)
• High-speed 100-MHz operation (10 ns Read/Write cycle time)
• Low power (ICC = 35 mA)
• Fully asynchronous and simultaneous Read and Write operation
• Empty, Full, and Programmable Almost Empty and
   Almost Full status flags
• TTL-compatible
• Expandable in width
• Output Enable (OE) pin
• Independent Read and Write enable pins
• Center power and ground pins for reduced noise
• Width-expansion capability
• Space saving 7 mm × 7 mm 32-pin TQFP
• Pin-compatible and functionally equivalent to
   IDT72421, 72201, 72211, 72221, 72231, and 72241