So yeah, just to summarize: S3 on lower SPI frequencies seems to sample MISO data too late . Adjusting params like .input_delay_ns or .dummy_bits should help to solve this, but does not and in fact, does the opposite - only seems to make things worse. Using SPI_DEVICE_NO_DUMMY flag overrides the int...

I didn’t look into it in detail, but there are probably answers to the questions here. And I think this is intentional and conscious. https://github.com/espressif/esp-idf/blob/c8243465e45489835d645bf217a6929fd0c01b7f/components/hal/spi_hal.c#L133 iiinteresting... So the debug output print of spi_ha...

I see, so what I already did was to set both .command_bits and .address_bits to 0 as well as .spics_io_num to -1 and doing the write/read manually byte-by-byte, which allows me to have very safe delays between CS change as well as each byte transfer. This seems to have same effect as setting SPI_DEV...

I'm also having trouble setting correct timing with S3 and IDF v5.2-dev (only SPI Mode 2 seems correct) or IDFv4.4.6 (only SPI Mode 0 and 2 seems correct) while results on logic analyzer are correct for all modes. Something does not seem right.

Thanks for sharing the solution, I had no Idea this was possible. Although I suppose the easier would be to disable USB-Serail-JTAG peripheral alltogether and use JTAG pins directly with external USB-JTAG adapter (like ESP-PROG for example), just like you would with ESP32's with no USB peripheral. T...

There is now also a NCM example on ESP-IDF master (possibly upcommin v5.2): https://github.com/espressif/esp-idf/tr ... e/tusb_ncm

So I wonder if we could "just" swap WIFI for NETIF to get TCP connection to S2/S3 over USB...

Reminds me of situation that happened to me - debug firmware build with virtual efuses (therefore no physical encryption) was OTA uploaded to fully secured device with HW efuses, secure boot and encryprions. NVS was rendered unreadable and if using example NVS init procedures it would be wiped by de...

NVS for configurations for sure. I did not try FAT, I had issues with SPIFFS, but LittleFS turned out to be faster and without issues - used that one for storing webpages in 4MB partition for example.

Has anyone measured the SPI ethernet throughput with S3 yet? Preferably with KSZ8851..

I may have project where ESP32 RMII can't be used because of high pin usage while not needing super-fast ethernet anyways, also builtin USB-JTAG saves other 4 pins, so the S3 seems to be a good fit

Could also consider using external oscillator as clock source for both ESP32 and ethernet PHY. I had issues when using ESP32 or LAN8720 as clock source, but external oscillator works reliably.