64 Mbit DataFlash with 85 MHz SPI — what it means for the bus
The Adesto AT45DB641E-MWHN-Y is a 64 Mbit serial DataFlash memory using the SPI interface, clocked at 85 MHz. It is organized as 264 bytes per page across 32K pages.
Page write timing and the 8 µs / 5 ms spec
Write-cycle time is 8 µs for a word write and 5 ms for a full page program. The 5 ms page-write window matters for systems that must hold off other bus traffic during a write — a 5 ms latency is short enough for most data-logging and firmware-update routines but needs accounting in a real-time scheduler.
