STM32H7 FMC + ST7789 LCD

[baycanakcay]

Hi,
I am trying to interface Stm32h745 controller with a 240x320 TFT LCD over FMC. Interesting thing is, when I manually control lcd control and data pins(Set them as GPIO_OUTPUT_PP), Lcd works, but when I switched to FMC it does not. Tried lots of timing configuration but it did not help.
Here is the init for FMC

      .Instance = FMC_NORSRAM_DEVICE;
      .Extended = FMC_NORSRAM_EXTENDED_DEVICE;
      .Init.NSBank = FMC_NORSRAM_BANK1;
      .Init.DataAddressMux = FMC_DATA_ADDRESS_MUX_DISABLE;
      .Init.MemoryType = FMC_MEMORY_TYPE_SRAM;
      .Init.MemoryDataWidth = FMC_NORSRAM_MEM_BUS_WIDTH_8;
      .Init.BurstAccessMode = FMC_BURST_ACCESS_MODE_DISABLE;
      .Init.WaitSignalPolarity = FMC_WAIT_SIGNAL_POLARITY_LOW;
      .Init.WaitSignalActive = FMC_WAIT_TIMING_BEFORE_WS;
      .Init.WriteOperation = FMC_WRITE_OPERATION_ENABLE;
      .Init.WaitSignal = FMC_WAIT_SIGNAL_DISABLE;
      .Init.ExtendedMode = FMC_EXTENDED_MODE_DISABLE;
      .Init.AsynchronousWait = FMC_ASYNCHRONOUS_WAIT_DISABLE;
      .Init.WriteBurst = FMC_WRITE_BURST_DISABLE;
      .Init.ContinuousClock = FMC_CONTINUOUS_CLOCK_SYNC_ONLY;
      .Init.WriteFifo = FMC_WRITE_FIFO_DISABLE;
      instance->deviceHandleAsRam.Init.PageSize = FMC_PAGE_SIZE_NONE;

      FMC_NORSRAM_TimingTypeDef Timing = {0};
      Timing.AddressSetupTime      = 15;   // 1 cycle = 16.67 ns
      Timing.AddressHoldTime       = 15;   // 1 cycle hold time
      Timing.DataSetupTime         = 255;   // 4 cycles ≈ 66.7 ns
      Timing.BusTurnAroundDuration = 15;
      Timing.CLKDivision           = 16;   // Unused in SRAM mode
      Timing.DataLatency           = 17;   // Not used in mode A
      Timing.AccessMode            = FMC_ACCESS_MODE_A;
      
      instance->deviceTiming = Timing;

Tried FMC peripheral clk from 240 Mhz down to 15Mhz
LCD command/data selection connected to A0, and I am bank swapping from0x60000000 to 0xC0000000

#define LCD_BASE_ADDRESS     ((uint32_t)0xC0000000)

#define Lcd_CmdWrite(cmd)	  *((__IO uint8_t*)LCD_BASE_ADDRESS) = cmd
#define Lcd_DataWrite(data)  *((__IO uint8_t*)((LCD_BASE_ADDRESS) + (1 << (0 + 1)))) = data

 Here is the Logic Analyzer screen for 160Mhz Fmc Clock for the sequence below

   Lcd_CmdWrite(0xFF);    

   Lcd_DataWrite(0x00);

   Lcd_CmdWrite(0xAA);    

   Lcd_DataWrite(0x55);

 And here is the same saquence output with manual GPIO Control

Thanks for any help

[Dor_RH]

Hello @baycanakcay,

You might find this post helpful: Sending Data to TFT LCD via FMC Fails. It may assist you in your application by providing insights and solutions.

I hope this information is helpful. If it resolves your query, please mark this topic as the solution to assist others in finding the answer more quickly. Thank you for your contribution.

Best regards, 

Dor_RH

[baycanakcay · Accepted solution]

Hi Dor_Rh,
Thanks for the information. I already fixed the problem.

Best regards

Baycan

[Dor_RH]

Hello @baycanakcay,

Thank you for informing us about the resolution of the issue.
Could you share the solution or steps you took to resolve the problem?
This information could benefit other customers who may face similar challenges.

We appreciate your cooperation.

Best regards, 

Dor_RH