General • Pico's BOOTSEL circuit appears to violate the flash's power-up requirements

I've been reading the datasheet for the W25Q16JV - the SPI flash chip used on the Pico - and noticed a potential issue with the BOOTSEL circuit. The datasheet states:

• "The /CS input must track the VCC supply level at power-up and power-down"
• "Note that the chip select pin (/CS) must track the VCC supply level at power-up until the VCC-min level and tVSL time delay is reached"

However, on the Pico, pressing BOOTSEL pulls the chip select pin low during power-up, seemingly violating this requirement. Does this cause any issues? Are there any ways of entering BOOTSEL mode while respecting the flash's datasheet?

Statistics: Posted by JimmyJ — Mon Mar 10, 2025 5:19 am

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