Description

Allows routing of ESP32C3 and ESP32S3 internal hardware usb-jtag
to external gpio pins making ESP32S3/C3 cheap and fast JTAG for
programming other devices.

Once enabled this ESP32 hardware services JTAG by itself
so no other software interrupts or any server running
is needed.

Code Size

12 lines of code to enable, 6 lines to disable here is arduino example

#if CONFIG_IDF_TARGET_ESP32S3
#define OMATRIX_TCK 85
#define OMATRIX_TMS 86
#define OMATRIX_TDI 87
#define OMATRIX_SRST 251
#define IMATRIX_TDO 251
#endif

#if CONFIG_IDF_TARGET_ESP32C3
#define OMATRIX_TCK 36
#define OMATRIX_TMS 37
#define OMATRIX_TDI 38
#define OMATRIX_SRST 127
#define IMATRIX_TDO 39
#endif

void route_usb_jtag_to_gpio()
{
digitalWrite(LED_BUILTIN, LED_ON);
pinMode(PIN_TCK, OUTPUT);
pinMode(PIN_TMS, OUTPUT);
pinMode(PIN_TDI, OUTPUT);
pinMode(PIN_TDO, INPUT);
pinMode(PIN_SRST, OUTPUT);
WRITE_PERI_REG(USB_SERIAL_JTAG_CONF0_REG,
READ_PERI_REG(USB_SERIAL_JTAG_CONF0_REG)
| USB_SERIAL_JTAG_USB_JTAG_BRIDGE_EN);
// esp_rom_gpio_connect_out_signal(GPIO, IOMATRIX, false, false);
esp_rom_gpio_connect_out_signal(PIN_TCK, OMATRIX_TCK, false, false);
esp_rom_gpio_connect_out_signal(PIN_TMS, OMATRIX_TMS, false, false);
esp_rom_gpio_connect_out_signal(PIN_TDI, OMATRIX_TDI, false, false);
esp_rom_gpio_connect_out_signal(PIN_SRST, OMATRIX_SRST, false, false);
esp_rom_gpio_connect_in_signal (PIN_TDO, IMATRIX_TDO, false);
}

void unroute_usb_jtag_to_gpio()
{
WRITE_PERI_REG(USB_SERIAL_JTAG_CONF0_REG,
READ_PERI_REG(USB_SERIAL_JTAG_CONF0_REG)
& ~USB_SERIAL_JTAG_USB_JTAG_BRIDGE_EN);
pinMode(PIN_TCK, INPUT);
pinMode(PIN_TMS, INPUT);
pinMode(PIN_TDI, INPUT);
pinMode(PIN_TDO, INPUT);
pinMode(PIN_SRST, INPUT);
digitalWrite(LED_BUILTIN, LED_OFF);
}

Implementation

I hope the MicroPython maintainers or community will implement this feature

Code of Conduct

Yes, I agree