Active QDR II+ SRAM — 633 MHz, 36 Mbit
The CY7C1263XV18-633BZXC is a 36 Mbit synchronous SRAM built on the QDR II+ architecture, clocked at 633 MHz. Organized 2M x 18, it delivers a read and a write data word on every rising and falling clock edge — four data transfers per cycle — for a peak bandwidth that keeps a high-performance FPGA or ASIC's internal SRAM fed without wait states. The 165-FBGA package (13x15 mm) routes the parallel interface to a compact BGA footprint. The 1.7 V to 1.9 V core supply aligns with low-voltage 1.8 V logic families common on modern processor and FPGA boards.
Bandwidth and bus timing
At 633 MHz, the QDR II+ interface performs four data transfers per clock cycle — two reads and two writes — so the effective data rate per I/O pin is 2.5 Gbps. The 18-bit-wide data bus yields a theoretical peak throughput of 45 Gbit/s, limited by the I/O buffer drive strength and board trace impedance. The parallel memory interface uses separate read and write data ports, eliminating bus-turnaround dead cycles that plague common I/O designs. This matters for networking gear or real-time signal processing where back-to-back read-write sequences are the norm.
Temperature grade and supply rails
The 1.7 V to 1.9 V supply range includes the nominal 1.8 V rail with margin for ripple and DC offset. The 165-LBGA package (13x15 mm, 1.0 mm ball pitch) requires a multi-layer PCB with controlled-impedance traces for the high-speed parallel bus. The BGA footprint is standard for high-density memory; the 1.0 mm pitch is hand-solderable with a hot-air rework station and a stencil.