I think they just don't want their flash chips to be blamed if signals start appearing on the SPI pins too early and the flash can't work properly. Browse an older SPI flash DS, for example SST25VF010A:
It's not going to blow up or anything, just "may not" work, so they don't want you to be signalling it until it is fully out of reset. Winbond is a bit more insistent about it I guess. I downloaded my copy of the W25Q16JV DS from Mouser. I wonder what old Winbond datasheets say... ![:|]( "Neutral")
Code:
[pg 4] CE# / Chip Enable / The device is enabled by a high-to-low transition on CE#. CE# must remain low for the duration of any command sequence[pg 20] Figure 6.4: Power Up Timing Diagram Chip selection is not allowed. All commands are rejected by the device.But in later datasheets Microchip/SST changed 'reject' to something more accurate: Chip selection is not allowed. Commands may not be accepted or properly interpreted by the device.
Statistics: Posted by katak255 — Mon Mar 10, 2025 6:45 am