Memory density and bus width for the data buffer
The CY7C1381KV33-133AXI packs 18 Mbit of synchronous SRAM organized as 512K words by 36 bits wide. That 36-bit data bus matches a 32-bit processor core plus parity or ECC nibble without needing a second chip — the extra four bits carry the check byte on the same bus cycle.
Clock rate and access time — the read throughput ceiling
Rated for a 133 MHz clock, the part delivers a 7.5 ns cycle time. The 6.5 ns access time from the clock edge means the data appears on the bus within that window — the controller must latch it before the next rising edge, so the board trace delay plus input setup time must fit inside the remaining 1.0 ns margin. At 133 MHz the 36-bit bus delivers a peak read bandwidth of roughly 598 MB/s (133 MHz × 4 bytes per word). The synchronous pipeline keeps the address bus free for the next access while the current read completes, which matters for back-to-back cache-line fills.
Supply rail tolerance and temperature grade
Operates from 3.135 V to 3.6 V — a 3.3 V nominal rail with ±5 % regulation stays inside this window.
Package and board-fit for the 100-TQFP
Supplied in a 100-lead TQFP with a 14 mm × 20 mm body (EIAJ standard). The 0.5 mm pitch demands a controlled-impedance stack-up on the fan-out layers — the inner rows of the 36-bit data bus need at least a four-layer board to avoid signal-integrity issues at 133 MHz. Surface-mount assembly with a tray carrier. The package is RoHS-compatible per Infineon's standard green molding compound; no moisture-sensitive level is stated, but a 24-hour bake at 125 °C before reflow is prudent if the tray seal is broken.