Functional Description
The CY7C436X4 is a monolithic, high-speed, low-power, CMOS Bidirectional Synchronous (clocked) FIFO memory which supports clock frequencies up to 133 MHz and has read access times as fast as 6 ns. Two independent 1K/4K/16K x 36 dual-port SRAM FIFOs on board each chip buffer data in opposite directions. FIFO data on Port B can be input and output in 36-bit, 18-bit, or 9-bit formats with a choice of Big or Little Endian configurations.

Features
• High-speed, low-power, bidirectional, First-In, First-Out (FIFO) memories with bus matching capabilities
• 1K x36 x2 (CY7C43644)
• 4K x36 x2 (CY7C43664)
• 16K x36 x2 (CY7C43684)
• 0.35-micron CMOS for optimum speed/power
• High-speed 133-MHz operation (7.5 ns read/write cycle times)
• Low power
    — ICC = 100 mA
    — ISB = 10 mA
• Fully asynchronous and simultaneous read and write operation permitted
• Mailbox bypass register for each FIFO
• Parallel and Serial Programmable Almost-Full and Almost-Empty flags
• Retransmit function
• Standard or FWFT mode user selectable
• Partial Reset
• Big or Little Endian format for word or byte bus sizes
• 128-pin TQFP packaging
• Easily expandable in width and depth