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Connecting SD-CARD and JTAG to the ESP32-U4WDH chip using the HS1 pins

Posted: Wed Feb 09, 2022 3:55 pm
by f.contin@seneca.it
We have been testing the ESP32 DEV KIT with the ESP32 WROOM and we are amazed by this chip and all the tools/SDK.
Now we are developing our new board that will use the ESP32-U4WDH (4Mb of embedded flash) and needs a SD-CARD for data logging with possibly the JTAG debug.

In the ESP32 Series Datasheet Version 3.8 we found a note:
• The pin-pin mapping between ESP32-U4WDH and the embedded flash is as follows: GPIO16 = CS#, GPIO17 = IO1/DO, SD_CMD = IO3/HOLD#, SD_CLK = CLK, SD_DATA_0
= IO2/WP#, SD_DATA_1 = IO0/DI. The pins used for embedded flash are not recommended for other uses.

This means that the flash SPI pins are connected internally through the IO_MUX and it's not allowed to configure the IO_MUX for the HS1 Peripheral (SPI2 or HSPI with 4 data bits interface) setting MCU_SEL to "function 3"?

Thanks!

Re: Connecting SD-CARD and JTAG to the ESP32-U4WDH chip using the HS1 pins

Posted: Thu Feb 10, 2022 3:18 am
by ESP_LJH
Yes, those pins could not be used to connect SD card, you could only use HS2: MTDI MTDO MTCK MTMS GPIO2 GPIO4.