ESP32-C3 has three strapping pins: GPIO2, GPIO8, and GPIO9. During the chip's system reset, the strapping pins sample their voltage levels and store them into the latch until the chip is powered down or shut down. Depending on the stored voltage levels, the chip will enter different boot modes after system reset. The correspondence between the voltage levels and the boot modes is shown in Table 5.5. After reset, the strapping pins function as normal pins.
Table 5.5. Voltage level of strapping pins and corresponding boot mode
|Strapping Pins||Default||SPI Boot||Download Boot|
|GPIO9||Weak internal pull-up||1||0|