64 Mbit parallel NOR Flash in a 48-ball BGA
The Microchip SST38VF6403B-70I/CD is a 64 Mbit parallel NOR Flash memory organized as 4M x 16. It is a member of the SST38 series, designed for code shadowing, execute-in-place (XIP), and parameter storage in embedded systems where fast random reads matter. The 70 ns access time means the bus can be run at up to roughly 14 MHz without wait states on a typical 16-bit microcontroller — useful for boot code or real-time lookup tables where SPI Flash latency would stall the pipeline. Supply voltage spans 2.7V to 3.6V, so it runs cleanly off a 3.3V rail with margin for brownout.
70 ns access time — timing margin on the bus
In a system with a 16-bit MCU running at 12 MHz to 16 MHz, this gives roughly one to two CPU clock cycles of margin for address decoding and PCB trace delay. If you are upgrading from a slower 90 ns or 120 ns part, the SST38VF6403B-70I/CD buys you setup slack without changing the bus timing configuration. The parallel interface means the MCU reads it like internal SRAM — no SPI command overhead, no sector-read latency. Word and page write cycle time is 10 µs, typical for NOR Flash of this generation.
48-TFBGA — footprint and rework considerations
The ball array is not the coarsest — expect a 0.8 mm or 0.65 mm pitch. That means via-in-pad or microvia fanout on anything less than a four-layer board. The supplier device package is 48-TFBGA (6x8). Tray shipment is standard for BGA parts; if your pick-and-place line feeds from tape, expect a transfer to tape on request at extra cost.
ROHS3 compliant. For dual-source resilience, the SST39VF1601-70-4I-B3KE-T is a 16 Mbit parallel NOR from the same SST family with matching 70 ns access time and 2.7V supply — but at one-quarter the density, so it is a die-shrink or cost-reduction alternative only if your code fits in 16 Mbit.