64Mbit parallel NOR flash — 70 ns access, 3.3 V single-rail
The SST39VF6401B-70-4C-EKE is a 64 Mbit parallel NOR flash from Microchip's SST39 MPF™ family, organized as 4M x 16 bits with a 70 ns access time. The parallel interface means the entire memory array is visible on the address and data bus — no SPI serialization latency, so the CPU can execute code directly (XIP) without copying to RAM first.
Package and board-fit — 48-TSOP footprint
Housed in a 48-TFSOP package (0.724", 18.40 mm width) with the supplier device package listed as 48-TSOP — the standard thin small-outline package footprint for parallel NOR flash in this density class. Surface-mount assembly on a standard JEDEC TSOP-48 land pattern; the 0.50 mm pin pitch requires controlled solder-paste deposition but is well within the capability of any production SMT line.
Temperature grade and operating environment
For an industrial panel or telecom closet that stays within this range, the part operates within its guaranteed window with no derating needed.
Programming throughput and firmware update window
Word and page write cycle time is 10 µs — fast enough that a full 64 Mbit firmware image can be programmed in well under a second over the parallel bus, assuming the host controller drives the write strobe at the rated cycle time. The 70 ns access time means the read cycle matches the bus timing of most ARM and x86 embedded processors without inserting wait states at moderate clock speeds.
Lifecycle and sourcing posture
RoHS3 compliant, so it ships into EU and global markets without a RoHS exemption expiry concern.