90 ns access — timing margin for the read cycle
The CY27C512-90ZC: For a microcontroller running at 12 MHz (83 ns cycle), the EPROM's access time consumes the entire read cycle — the address-to-data path must be direct, with no added buffer delay, or the setup time at the controller's data input is violated. The parallel interface means all 8 data lines and 16 address lines route to the controller bus — no serial shift overhead, but the PCB trace length matching matters more than with a serial flash because the parallel setup/hold window is tighter.
Package and board-fit — 32-TSOP I, surface mount
Housed in a 32-TFSOP (0.724", 18.40 mm width) — the JEDEC standard TSOP I footprint with 0.50 mm pin pitch. Supplied in bulk (tray or tube), not tape-and-reel — a pick-and-place feeder change may be needed if the line is set up for 8 mm or 12 mm tape.
5 V supply and commercial temperature range
RoHS non-compliant — the part carries a tin-lead finish. This is typical for legacy EPROMs and is acceptable under the RoHS exemption for lead in solder for certain applications (server, telecom infrastructure, military). For RoHS-required builds, a lead-free alternative from the same family would need to be verified.