WDT reset on WPD of some pins

[reinderien]

To manage noise & power I'm setting unused pins on my ESP32C3 MINI 1 as such:

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1.     static const gpio_config_t unused = {
2.         .pin_bit_mask =
3.               (1u << GPIO_NUM_0)
4.             | (1u << GPIO_NUM_1)
5.             | (1u << GPIO_NUM_2)
6.             | (1u << GPIO_NUM_3)
7.             | (1u << GPIO_NUM_10),
8.         .mode = GPIO_MODE_DISABLE,
9.         .pull_up_en = GPIO_PULLUP_DISABLE,
10.         .pull_down_en = GPIO_PULLDOWN_ENABLE,
11.         .intr_type = GPIO_INTR_DISABLE,
12.     };
13.     ESP_ERROR_CHECK_WITHOUT_ABORT(gpio_config(&unused));

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If I extend this to GPIO 15,16,17, then the SOC hangs and the watchdog kills it, even though these pins are shown as unused in the module's circuit diagram. My current theory is that since their default MUX function is SPI, the module has some undocumented SPI bus (bootloader?)

What's actually attached to these pins?

[MicroController]

What's actually attached to these pins?

The on-chip or on-module flash memory which holds the application code. Don't mess with those pins

[reinderien]

The on-chip or on-module flash memory which holds the application code. Don't mess with those pins

Good to know; but - I wish that that were somehow indicated here, instead of a big empty space: