ESP-WROOM-32 Bootstrapping
Posted: Fri Sep 29, 2017 6:43 pm
Hello,
I've got a few questions relating to the bootstrapping pins on the ESP module.
Specifically:
1) What is the purpose of the "timing of SDIO slave" strapping pins? I am guessing that the state of these doesn't really matter as it can also be configured in FW. But how can the flash memory properly configure the state of these registers on bootup if the proper configuration is required for the flash to communicate with the esp32 in the first place?
2) Similar question about "Voltage of Internal LDO (VDD_SDIO)". From my research it appears that all the flash memory modules included in the ESP-WROOM-32 module will be of the 3.3V variety. Is this configuration also managed by FW in addition to the MTDI pin? How can that happen if the voltage needs to be correct for the flash module to work? For example, if the MTDI pin was pulled high on bootup, thus selecting a 1.8V VDD_SDIO voltage level, would the flash memory overwrite that and force a 3.3V VDD_SDIO?
Thanks,
Connor
I've got a few questions relating to the bootstrapping pins on the ESP module.
Specifically:
1) What is the purpose of the "timing of SDIO slave" strapping pins? I am guessing that the state of these doesn't really matter as it can also be configured in FW. But how can the flash memory properly configure the state of these registers on bootup if the proper configuration is required for the flash to communicate with the esp32 in the first place?
2) Similar question about "Voltage of Internal LDO (VDD_SDIO)". From my research it appears that all the flash memory modules included in the ESP-WROOM-32 module will be of the 3.3V variety. Is this configuration also managed by FW in addition to the MTDI pin? How can that happen if the voltage needs to be correct for the flash module to work? For example, if the MTDI pin was pulled high on bootup, thus selecting a 1.8V VDD_SDIO voltage level, would the flash memory overwrite that and force a 3.3V VDD_SDIO?
Thanks,
Connor