ETH is not working when integrating LWIP with LTDC

[S_1]

We are using STM32F429IGTx microcontroller for our application. We use STM32CubeMX with Keil IDE v5. Our application needs both LCD and internet connectivity. we try to use 800 x 480 TFT LCD ( RGB565 ) for display and ethernet for internet connectivity. So, we configure LTDC with RGB565 and LWIP with ETH ( RMII ) using CubeMX. When we build LTDC and LWIP separately, both work well. When we integrate, LCD works but ETH is not working. We tried to solve the issue but we can’t find the source of it. There isn’t a pin muxing and memory issue. Then I started to comment LTDC initialization function call then ETH is started working. So, I tried to get to the root of it. At last, we figured out, when we comment out either __HAL_RCC_LTDC_CLK_ENABLE() function or HAL_GPIO_Init(GPIOF, &GPIO_InitStruct) function which is the LTDC DE pin, then ETH is working but we can't understand why?

I have attached my CubeMx report pdf file ( meraspluginsapp2.pdf ) and the evaluation board we use for your reference.

[DFuchs]

Hi,

perhaps a connection between LTDC_DE and any ETH-Pin?

Kind regards

Daniel

[S_1]

LTDC_DE is on GPIO F but none of the ETH pins use GPIO F.

[DFuchs]

Hi,

i meant a physical connection by solder paste or a layout problem.

As long as LTDC_DE isn't configured it is an input and doesn't affect other outputs much.

Kind regards

Daniel

[S_1]

Thanks for your reply.

I checked the board and there isn't any physical connection issue.

Some suggest me to check the NVIC interrupt but I didn't know how to.

I only enabled ETH IRQ but I didn't enable LTDC IRQ.

[S_1]

I use MCO1 for ETH clock at 25MHz (HSE) for LAN8720A (RMII). Is that a problem?