Use this forum to chat about hardware specific topics for the ESP8266 (peripherals, memory, clocks, JTAG, programming)

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By michaeltandy
#55543 I was wondering what commands the ESP8266 uses when my code writes to the SPI flash. So I checked with an oscilloscope - it was a bit fiddly, but here are the results:

Code: Select allAPI Call                SPI Command  Note
spi_flash_erase_sector    0x20       Repeated status reads (command 0x05) until erase completes
spi_flash_read            0xBB       Dual SPI
spi_flash_write           0x02       Single status read, test completed immediately


I figured I'd report them here in case anyone else is looking for an answer to the same question :)

For some graphs and other details, see this blog post