ESP32-C61 on-chip flash power pin confusion
Posted: Mon Aug 24, 2026 4:39 am
I'm reading the "ESP32-C61 Series Datasheet v1.0" and designing a simple, custom PC board with serial communication.
I have the ESP32-C61HF4 (4MB on-chip flash)
Page 14
"Notice: For ESP32-C61HF4, SPICS0, SPIQ, SPIWP, VDD_SPI, SPIHD, SPICLK, and SPID pins are not connected (NC)."
Page 17
"4. For ESP32-C61HF4, the SPICS0, SPIQ, SPIWP, VDD_SPI, SPIHD, SPICLK, and SPID pins are not connected (NC)"
Page 26
"For variants with in-package flash/PSRAM, the in-package flash or PSRAM must be powered by VDD_SPI, and
the corresponding pin cannot be used as a digital function pin"
This seems to be contradicting information - do I need to put 3.3v on the VDD_SPI pin or is it Not Connected? My guess is that its NC and page 26 is out of date, but I'm posting here to be sure. I'm investigating checksum errors while writing to the onboard flash.
I have the ESP32-C61HF4 (4MB on-chip flash)
Page 14
"Notice: For ESP32-C61HF4, SPICS0, SPIQ, SPIWP, VDD_SPI, SPIHD, SPICLK, and SPID pins are not connected (NC)."
Page 17
"4. For ESP32-C61HF4, the SPICS0, SPIQ, SPIWP, VDD_SPI, SPIHD, SPICLK, and SPID pins are not connected (NC)"
Page 26
"For variants with in-package flash/PSRAM, the in-package flash or PSRAM must be powered by VDD_SPI, and
the corresponding pin cannot be used as a digital function pin"
This seems to be contradicting information - do I need to put 3.3v on the VDD_SPI pin or is it Not Connected? My guess is that its NC and page 26 is out of date, but I'm posting here to be sure. I'm investigating checksum errors while writing to the onboard flash.