当时钟频率为 480MHz 时，STM32H743 的 FMC 能否以高于 1.6MHz 的速度驱动 16 位 8080 总线？

Question

我正在使用 STM32H743 的 FMC 来驱动一个 16 位 8080 总线 LCD 控制器。

我试过使用 DMA、MDMA 和 CPU 循环通过 FMC 将数据传输到 8080 总线。

传输频率与使用 DMA、MDMA 还是 CPU-loop 无关。这让我觉得 DMA/MDMA/CPU-loop 不是限制因素。

在 480MHz FMC 时钟下，传输仅发生在 1.6MHz，在 16 位彩色 320x240 LCD 上我只有 20fps。

在 240MHz 的 FMC 时钟下，传输仅以 0.8MHz 发生，以较慢的速度依此类推。

我还尝试将各种设置和保持时间减少到 1 和 0 个周期，但这（令人惊讶地）没有影响 8080 总线上的波形。

我的（Cube-MX生成的）FMC初始化代码是：

/* FMC initialization function */
static void MX_FMC_Init(void)
{

  /* USER CODE BEGIN FMC_Init 0 */

  /* USER CODE END FMC_Init 0 */

  FMC_NORSRAM_TimingTypeDef Timing = {0};
  FMC_NORSRAM_TimingTypeDef ExtTiming = {0};

  /* USER CODE BEGIN FMC_Init 1 */

  /* USER CODE END FMC_Init 1 */

  /** Perform the SRAM1 memory initialization sequence
  */
  hsram1.Instance = FMC_NORSRAM_DEVICE;
  hsram1.Extended = FMC_NORSRAM_EXTENDED_DEVICE;
  /* hsram1.Init */
  hsram1.Init.NSBank = FMC_NORSRAM_BANK2;
  hsram1.Init.DataAddressMux = FMC_DATA_ADDRESS_MUX_DISABLE;
  hsram1.Init.MemoryType = FMC_MEMORY_TYPE_SRAM;
  hsram1.Init.MemoryDataWidth = FMC_NORSRAM_MEM_BUS_WIDTH_16;
  hsram1.Init.BurstAccessMode = FMC_BURST_ACCESS_MODE_DISABLE;
  hsram1.Init.WaitSignalPolarity = FMC_WAIT_SIGNAL_POLARITY_LOW;
  hsram1.Init.WaitSignalActive = FMC_WAIT_TIMING_BEFORE_WS;
  hsram1.Init.WriteOperation = FMC_WRITE_OPERATION_ENABLE;
  hsram1.Init.WaitSignal = FMC_WAIT_SIGNAL_DISABLE;
  hsram1.Init.ExtendedMode = FMC_EXTENDED_MODE_ENABLE;
  hsram1.Init.AsynchronousWait = FMC_ASYNCHRONOUS_WAIT_DISABLE;
  hsram1.Init.WriteBurst = FMC_WRITE_BURST_DISABLE;
  hsram1.Init.ContinuousClock = FMC_CONTINUOUS_CLOCK_SYNC_ONLY;
  hsram1.Init.WriteFifo = FMC_WRITE_FIFO_DISABLE;
  hsram1.Init.PageSize = FMC_PAGE_SIZE_NONE;
  /* Timing */
  Timing.AddressSetupTime = 3;
  Timing.AddressHoldTime = 15;
  Timing.DataSetupTime = 4;
  Timing.BusTurnAroundDuration = 1;
  Timing.CLKDivision = 16;
  Timing.DataLatency = 17;
  Timing.AccessMode = FMC_ACCESS_MODE_A;
  /* ExtTiming */
  ExtTiming.AddressSetupTime = 3;
  ExtTiming.AddressHoldTime = 15;
  ExtTiming.DataSetupTime = 4;
  ExtTiming.BusTurnAroundDuration = 1;
  ExtTiming.CLKDivision = 16;
  ExtTiming.DataLatency = 17;
  ExtTiming.AccessMode = FMC_ACCESS_MODE_A;

  if (HAL_SRAM_Init(&hsram1, &Timing, &ExtTiming) != HAL_OK)
  {
    Error_Handler( );
  }

  HAL_SetFMCMemorySwappingConfig(FMC_SWAPBMAP_SDRAM_SRAM);
}

我修改后的设置是：

  Timing.AddressSetupTime = 1;
  Timing.AddressHoldTime = 1;
  Timing.DataSetupTime = 1;
  Timing.BusTurnAroundDuration = 1; // not needed
  Timing.CLKDivision = 1; // not needed
  Timing.DataLatency = 34;
  Timing.AccessMode = FMC_ACCESS_MODE_A;
  ExtTiming.AddressSetupTime = 1;
  ExtTiming.AddressHoldTime = 1;
  ExtTiming.DataSetupTime = 1;
  ExtTiming.BusTurnAroundDuration = 1;  // not needed
  ExtTiming.CLKDivision = 1; // not needed
  ExtTiming.DataLatency = 34;
  ExtTiming.AccessMode = FMC_ACCESS_MODE_A;

和

  Timing.AddressSetupTime = 0;
  Timing.AddressHoldTime = 0;
  Timing.DataSetupTime = 0;
  Timing.BusTurnAroundDuration = 0; // not needed
  Timing.CLKDivision = 1; // not needed
  Timing.DataLatency = 0;
  Timing.AccessMode = FMC_ACCESS_MODE_A;
  ExtTiming.AddressSetupTime = 0;
  ExtTiming.AddressHoldTime = 0;
  ExtTiming.DataSetupTime = 0;
  ExtTiming.BusTurnAroundDuration = 0;  // not needed
  ExtTiming.CLKDivision = 1; // not needed
  ExtTiming.DataLatency = 34;
  ExtTiming.AccessMode = FMC_ACCESS_MODE_A;

（Cube-MX 生成的）时钟设置为：

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
  RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};

  /** Supply configuration update enable 
  */
  HAL_PWREx_ConfigSupply(PWR_LDO_SUPPLY);
  /** Configure the main internal regulator output voltage 
  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE0);

  while(!__HAL_PWR_GET_FLAG(PWR_FLAG_VOSRDY)) {}
  /** Macro to configure the PLL clock source 
  */
  __HAL_RCC_PLL_PLLSOURCE_CONFIG(RCC_PLLSOURCE_HSE);
  /** Initializes the CPU, AHB and APB busses clocks 
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 4;
  RCC_OscInitStruct.PLL.PLLN = 480;
  RCC_OscInitStruct.PLL.PLLP = 2;
  RCC_OscInitStruct.PLL.PLLQ = 20;
  RCC_OscInitStruct.PLL.PLLR = 2;
  RCC_OscInitStruct.PLL.PLLRGE = RCC_PLL1VCIRANGE_1;
  RCC_OscInitStruct.PLL.PLLVCOSEL = RCC_PLL1VCOWIDE;
  RCC_OscInitStruct.PLL.PLLFRACN = 0;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Initializes the CPU, AHB and APB busses clocks 
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2
                              |RCC_CLOCKTYPE_D3PCLK1|RCC_CLOCKTYPE_D1PCLK1;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.SYSCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB3CLKDivider = RCC_APB3_DIV2;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_APB1_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_APB2_DIV2;
  RCC_ClkInitStruct.APB4CLKDivider = RCC_APB4_DIV2;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK)
  {
    Error_Handler();
  }
  PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_SPI1|RCC_PERIPHCLK_USB
                              |RCC_PERIPHCLK_QSPI|RCC_PERIPHCLK_FMC;
  PeriphClkInitStruct.PLL2.PLL2M = 2;
  PeriphClkInitStruct.PLL2.PLL2N = 120;
  PeriphClkInitStruct.PLL2.PLL2P = 8;
  PeriphClkInitStruct.PLL2.PLL2Q = 2;
  PeriphClkInitStruct.PLL2.PLL2R = 1;
  PeriphClkInitStruct.PLL2.PLL2RGE = RCC_PLL2VCIRANGE_2;
  PeriphClkInitStruct.PLL2.PLL2VCOSEL = RCC_PLL2VCOWIDE;
  PeriphClkInitStruct.PLL2.PLL2FRACN = 0;
  PeriphClkInitStruct.FmcClockSelection = RCC_FMCCLKSOURCE_PLL2;
  PeriphClkInitStruct.QspiClockSelection = RCC_QSPICLKSOURCE_D1HCLK;
  PeriphClkInitStruct.Spi123ClockSelection = RCC_SPI123CLKSOURCE_PLL;
  PeriphClkInitStruct.UsbClockSelection = RCC_USBCLKSOURCE_PLL;
  if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Enable USB Voltage detector 
  */
  HAL_PWREx_EnableUSBVoltageDetector();
}

当使用 480MHz 时钟驱动时，如何使 STM32H743 上的 FMC 传输半字的速度快于 1.6MHz？

Answer 1

要使 FMC 运行快速，您必须配置要使用的银行。

我错误地配置了NE2 bank，然后使用了NE1 bank对应的地址。

完整详情：https://community.st.com/s/question/0D50X0000CAuyJ7SQJ/can-the-stm32h743s-fmc-drive-a-16bit-8080-bus-faster-than-16mhz-when-clocked-at-480mhz

当时钟频率为 480MHz 时，STM32H743 的 FMC 能否以高于 1.6MHz 的速度驱动 16 位 8080 总线？

Can the STM32H743's FMC drive a 16-bit 8080 bus faster than 1.6MHz when clocked at 480MHz?

stm32

dma

fmc

stm32h743

mdma