ESP32-S2 DMA transactions between SPI2 and external PSRAM

polamagdygeo
Posts: 4
Joined: Sun Apr 04, 2021 4:48 pm

ESP32-S2 DMA transactions between SPI2 and external PSRAM

Postby polamagdygeo » Sun Apr 04, 2021 5:08 pm

Hello

I'm planning to use ESP32-S2 in a new product that has a TFT screen and I want to let a DMA controller handle the transactions between external PSRAM (holding TFT screen buffer) and SPI2 (interfacing with the LCD).

Can this be done?

Is there any other better suggestion?

polamagdygeo
Posts: 4
Joined: Sun Apr 04, 2021 4:48 pm

Re: ESP32-S2 DMA transactions between SPI2 and external PSRAM

Postby polamagdygeo » Tue Apr 06, 2021 4:56 pm

Can someone clarify these points to me?

1-
External RAM cannot be used as a place to store DMA transaction descriptors or as a buffer for a DMA transfer to read from or write into. Any buffers that will be used in combination with DMA must be allocated using heap_caps_malloc(size, MALLOC_CAP_DMA) and can be freed using a standard free() call.
Reference https://docs.espressif.com/projects/esp ... l-ram.html

2-
EDMA is used by I2S0, SPI2, AES Accelerator, and SHA Accelerator. It can access both internal RAM and external RAM.
Reference technical reference manual page 359

max_guo
Posts: 1
Joined: Tue Apr 20, 2021 6:20 pm

Re: ESP32-S2 DMA transactions between SPI2 and external PSRAM

Postby max_guo » Tue Apr 20, 2021 6:24 pm

I have the same problem. Do you get it work?
ESP-IDF V4.2 is not support I2S EDMA yet. I do not know if the nonstable V4.3 support I2S EDMA or not.

polamagdygeo
Posts: 4
Joined: Sun Apr 04, 2021 4:48 pm

Re: ESP32-S2 DMA transactions between SPI2 and external PSRAM

Postby polamagdygeo » Sun Apr 25, 2021 4:49 pm

Not yet ,They told me that "The driver of EDMA is under development and need more time to finish and test it."

polamagdygeo
Posts: 4
Joined: Sun Apr 04, 2021 4:48 pm

Re: ESP32-S2 DMA transactions between SPI2 and external PSRAM

Postby polamagdygeo » Sun May 23, 2021 3:00 pm

Anyone can tell us ,Is this feature planned to be done or not and what's the expected date to release it?

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