ESP32-C6 UART1 wake-up modes

[msia.dev]

Hi,

First of all, sorry if I posted this in the wrong forum section, I think this mostly refers to preliminary ESP32-C6 documentation.

While researching how I can wake up HP core from auto light sleep using UART1, I stumbled upon a section in the Technical Reference Manual, related to different UART wake-up modes -- "26.4.8 Wake­up, page 637". Of 4 modes, the only one that seems to be implemented in the ESP-IDF is mode 0, allowing wake-up if a certain number of RX signal edges are detected.

I've tried changing the mode to the other 3 by adjusting the register value, but none of them seem to work. I can confirm that mode 0 does work, enabled either from ESP-IDF or by manually setting the correct register value. I've also confirmed that the register value is not being changed during light sleep entry/exit. Is there anything that I'm missing here?

For testing purposes, I'm using ESP32-C6-DevKitC-1 v1.2. UART1 is connected to GPIO4 (RX) and GPIO5 (TX) and uses XTAL as a clk source. "Power down Digital Peripheral in light sleep" and "Disable all GPIO when chip at sleep" are both turned off. This was tested on the master branch as well as the v5.1.1 release.
The reason for even trying to change modes is to use the ability of "mode 1" which states that it keeps the UART core working and is able to fill RX FIFO. With mode 0, the first packet gets cut or there is some garbage received which makes the system unusable. Before resorting to LP core I wanted to see if I can utilize mode 1 or 2 to be able to wake HP core but also get all data that was sent to UART.

Let me know if there is any additional info I can provide.

Also, do you have a rough estimate of when we can expect an updated Technical Reference Manual with a "Low-Power Management" section?

Thanks in advance!

[msia.dev]

Hi,

Bumping this post because we're a bit time-constrained, we're evaluating whether ESP32-C6 is going to work for our product, and there is still no answer.
If I should reach out via official Espressif channels instead of this forum, please let me know.