/*** *************************************************************************** * @file sdram.c * @brief sdram初始化，本代码移植于官方stm32f429discovery例程， * 并作出相应修改 * ****************************************************************************** * * * * *************************************************************************** ***/ #include "sdram.h" #include "stm32f4xx.h" /****************************************************************************************************** * 函 数 名: SDRAM_delay * 入口参数: 无 * 返 回 值: 无 * 函数功能: 简易延时函数，单位约为5ms * 说 明: 无 *******************************************************************************************************/ void SDRAM_delay(__IO uint32_t nCount) { __IO uint32_t index = 0; for (index = (100000 * nCount); index != 0; index--) { } } /****************************************************************************************************** * 函 数 名: SDRAM_GPIO_Config * 入口参数: 无 * 返 回 值: 无 * 函数功能: 配置GPIO * 说 明: 无 *******************************************************************************************************/ void SDRAM_GPIO_Config(void) { GPIO_InitTypeDef GPIO_InitStructure; RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC | RCC_AHB1Periph_GPIOD | RCC_AHB1Periph_GPIOE | RCC_AHB1Periph_GPIOF | RCC_AHB1Periph_GPIOG | RCC_AHB1Periph_GPIOH | RCC_AHB1Periph_GPIOI, ENABLE); // IO口配置 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; // 配置为复用功能 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz; GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; // 推挽输出 GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL; // 地址线 GPIO_PinAFConfig(FMC_A0_PORT, FMC_A0_PINSOURCE, FMC_A0_AF); GPIO_PinAFConfig(FMC_A1_PORT, FMC_A1_PINSOURCE, FMC_A1_AF); GPIO_PinAFConfig(FMC_A2_PORT, FMC_A2_PINSOURCE, FMC_A2_AF); GPIO_PinAFConfig(FMC_A3_PORT, FMC_A3_PINSOURCE, FMC_A3_AF); GPIO_PinAFConfig(FMC_A4_PORT, FMC_A4_PINSOURCE, FMC_A4_AF); GPIO_PinAFConfig(FMC_A5_PORT, FMC_A5_PINSOURCE, FMC_A5_AF); GPIO_PinAFConfig(FMC_A6_PORT, FMC_A6_PINSOURCE, FMC_A6_AF); GPIO_PinAFConfig(FMC_A7_PORT, FMC_A7_PINSOURCE, FMC_A7_AF); GPIO_PinAFConfig(FMC_A8_PORT, FMC_A8_PINSOURCE, FMC_A8_AF); GPIO_PinAFConfig(FMC_A9_PORT, FMC_A9_PINSOURCE, FMC_A9_AF); GPIO_PinAFConfig(FMC_A10_PORT, FMC_A10_PINSOURCE, FMC_A10_AF); GPIO_PinAFConfig(FMC_A11_PORT, FMC_A11_PINSOURCE, FMC_A11_AF); GPIO_InitStructure.GPIO_Pin = FMC_A0_PIN; GPIO_Init(FMC_A0_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_A1_PIN; GPIO_Init(FMC_A1_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_A2_PIN; GPIO_Init(FMC_A2_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_A3_PIN; GPIO_Init(FMC_A3_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_A4_PIN; GPIO_Init(FMC_A4_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_A5_PIN; GPIO_Init(FMC_A5_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_A6_PIN; GPIO_Init(FMC_A6_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_A7_PIN; GPIO_Init(FMC_A7_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_A8_PIN; GPIO_Init(FMC_A8_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_A9_PIN; GPIO_Init(FMC_A9_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_A10_PIN; GPIO_Init(FMC_A10_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_A11_PIN; GPIO_Init(FMC_A11_PORT, &GPIO_InitStructure); // 数据线 GPIO_PinAFConfig(FMC_D0_PORT, FMC_D0_PINSOURCE, FMC_D0_AF); GPIO_PinAFConfig(FMC_D1_PORT, FMC_D1_PINSOURCE, FMC_D1_AF); GPIO_PinAFConfig(FMC_D2_PORT, FMC_D2_PINSOURCE, FMC_D2_AF); GPIO_PinAFConfig(FMC_D3_PORT, FMC_D3_PINSOURCE, FMC_D3_AF); GPIO_PinAFConfig(FMC_D4_PORT, FMC_D4_PINSOURCE, FMC_D4_AF); GPIO_PinAFConfig(FMC_D5_PORT, FMC_D5_PINSOURCE, FMC_D5_AF); GPIO_PinAFConfig(FMC_D6_PORT, FMC_D6_PINSOURCE, FMC_D6_AF); GPIO_PinAFConfig(FMC_D7_PORT, FMC_D7_PINSOURCE, FMC_D7_AF); GPIO_PinAFConfig(FMC_D8_PORT, FMC_D8_PINSOURCE, FMC_D8_AF); GPIO_PinAFConfig(FMC_D9_PORT, FMC_D9_PINSOURCE, FMC_D9_AF); GPIO_PinAFConfig(FMC_D10_PORT, FMC_D10_PINSOURCE, FMC_D10_AF); GPIO_PinAFConfig(FMC_D11_PORT, FMC_D11_PINSOURCE, FMC_D11_AF); GPIO_PinAFConfig(FMC_D12_PORT, FMC_D12_PINSOURCE, FMC_D12_AF); GPIO_PinAFConfig(FMC_D13_PORT, FMC_D13_PINSOURCE, FMC_D13_AF); GPIO_PinAFConfig(FMC_D14_PORT, FMC_D14_PINSOURCE, FMC_D14_AF); GPIO_PinAFConfig(FMC_D15_PORT, FMC_D15_PINSOURCE, FMC_D15_AF); GPIO_PinAFConfig(FMC_D16_PORT, FMC_D16_PINSOURCE, FMC_D16_AF); GPIO_PinAFConfig(FMC_D17_PORT, FMC_D17_PINSOURCE, FMC_D17_AF); GPIO_PinAFConfig(FMC_D18_PORT, FMC_D18_PINSOURCE, FMC_D18_AF); GPIO_PinAFConfig(FMC_D19_PORT, FMC_D19_PINSOURCE, FMC_D19_AF); GPIO_PinAFConfig(FMC_D20_PORT, FMC_D20_PINSOURCE, FMC_D20_AF); GPIO_PinAFConfig(FMC_D21_PORT, FMC_D21_PINSOURCE, FMC_D21_AF); GPIO_PinAFConfig(FMC_D22_PORT, FMC_D22_PINSOURCE, FMC_D22_AF); GPIO_PinAFConfig(FMC_D23_PORT, FMC_D23_PINSOURCE, FMC_D23_AF); GPIO_PinAFConfig(FMC_D24_PORT, FMC_D24_PINSOURCE, FMC_D24_AF); GPIO_PinAFConfig(FMC_D25_PORT, FMC_D25_PINSOURCE, FMC_D25_AF); GPIO_PinAFConfig(FMC_D26_PORT, FMC_D26_PINSOURCE, FMC_D26_AF); GPIO_PinAFConfig(FMC_D27_PORT, FMC_D27_PINSOURCE, FMC_D27_AF); GPIO_PinAFConfig(FMC_D28_PORT, FMC_D28_PINSOURCE, FMC_D28_AF); GPIO_PinAFConfig(FMC_D29_PORT, FMC_D29_PINSOURCE, FMC_D29_AF); GPIO_PinAFConfig(FMC_D30_PORT, FMC_D30_PINSOURCE, FMC_D30_AF); GPIO_PinAFConfig(FMC_D31_PORT, FMC_D31_PINSOURCE, FMC_D31_AF); GPIO_InitStructure.GPIO_Pin = FMC_D0_PIN; GPIO_Init(FMC_D0_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D1_PIN; GPIO_Init(FMC_D1_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D2_PIN; GPIO_Init(FMC_D2_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D3_PIN; GPIO_Init(FMC_D3_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D4_PIN; GPIO_Init(FMC_D4_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D5_PIN; GPIO_Init(FMC_D5_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D6_PIN; GPIO_Init(FMC_D6_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D7_PIN; GPIO_Init(FMC_D7_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D8_PIN; GPIO_Init(FMC_D8_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D9_PIN; GPIO_Init(FMC_D9_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D10_PIN; GPIO_Init(FMC_D10_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D11_PIN; GPIO_Init(FMC_D11_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D12_PIN; GPIO_Init(FMC_D12_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D13_PIN; GPIO_Init(FMC_D13_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D14_PIN; GPIO_Init(FMC_D14_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D15_PIN; GPIO_Init(FMC_D15_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D16_PIN; GPIO_Init(FMC_D16_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D17_PIN; GPIO_Init(FMC_D17_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D18_PIN; GPIO_Init(FMC_D18_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D19_PIN; GPIO_Init(FMC_D19_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D20_PIN; GPIO_Init(FMC_D20_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D21_PIN; GPIO_Init(FMC_D21_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D22_PIN; GPIO_Init(FMC_D22_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D23_PIN; GPIO_Init(FMC_D23_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D24_PIN; GPIO_Init(FMC_D24_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D25_PIN; GPIO_Init(FMC_D25_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D26_PIN; GPIO_Init(FMC_D26_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D27_PIN; GPIO_Init(FMC_D27_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D28_PIN; GPIO_Init(FMC_D28_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D29_PIN; GPIO_Init(FMC_D29_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D30_PIN; GPIO_Init(FMC_D30_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_D31_PIN; GPIO_Init(FMC_D31_PORT, &GPIO_InitStructure); // 控制线 GPIO_PinAFConfig(FMC_CS_PORT, FMC_CS_PINSOURCE, FMC_CS_AF); GPIO_PinAFConfig(FMC_BA0_PORT, FMC_BA0_PINSOURCE, FMC_BA0_AF); GPIO_PinAFConfig(FMC_BA1_PORT, FMC_BA1_PINSOURCE, FMC_BA1_AF); GPIO_PinAFConfig(FMC_WE_PORT, FMC_WE_PINSOURCE, FMC_WE_AF); GPIO_PinAFConfig(FMC_RAS_PORT, FMC_RAS_PINSOURCE, FMC_RAS_AF); GPIO_PinAFConfig(FMC_CAS_PORT, FMC_CAS_PINSOURCE, FMC_CAS_AF); GPIO_PinAFConfig(FMC_CLK_PORT, FMC_CLK_PINSOURCE, FMC_CLK_AF); GPIO_PinAFConfig(FMC_CKE_PORT, FMC_CKE_PINSOURCE, FMC_CKE_AF); GPIO_PinAFConfig(FMC_UDQM_PORT, FMC_UDQM_PINSOURCE, FMC_UDQM_AF); GPIO_PinAFConfig(FMC_LDQM_PORT, FMC_LDQM_PINSOURCE, FMC_LDQM_AF); GPIO_PinAFConfig(FMC_NBL2_PORT, FMC_NBL2_PINSOURCE, FMC_NBL2_AF); GPIO_PinAFConfig(FMC_NBL3_PORT, FMC_NBL3_PINSOURCE, FMC_NBL3_AF); GPIO_InitStructure.GPIO_Pin = FMC_CS_PIN; GPIO_Init(FMC_CS_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_BA0_PIN; GPIO_Init(FMC_BA0_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_BA1_PIN; GPIO_Init(FMC_BA1_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_WE_PIN; GPIO_Init(FMC_WE_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_RAS_PIN; GPIO_Init(FMC_RAS_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_CAS_PIN; GPIO_Init(FMC_CAS_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_CLK_PIN; GPIO_Init(FMC_CLK_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_CKE_PIN; GPIO_Init(FMC_CKE_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_UDQM_PIN; GPIO_Init(FMC_UDQM_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_LDQM_PIN; GPIO_Init(FMC_LDQM_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_NBL2_PIN; GPIO_Init(FMC_NBL2_PORT, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = FMC_NBL3_PIN; GPIO_Init(FMC_NBL3_PORT, &GPIO_InitStructure); } /****************************************************************************************************** * 函 数 名: SDRAM_InitSequence * 入口参数: 无 * 返 回 值: 无 * 函数功能: SDRAM 参数配置 * 说 明: 配置SDRAM相关时序和控制方式 *******************************************************************************************************/ void SDRAM_InitSequence(void) { FMC_SDRAMCommandTypeDef FMC_SDRAMCommandStructure; // 定义寄存器变量 uint32_t Reg = 0; // 开启SDRAM时钟 FMC_SDRAMCommandStructure.FMC_CommandMode = FMC_Command_Mode_CLK_Enabled; // 选择要控制的区域 FMC_SDRAMCommandStructure.FMC_CommandTarget = FMC_COMMAND_TARGET_BANK; FMC_SDRAMCommandStructure.FMC_AutoRefreshNumber = 1; FMC_SDRAMCommandStructure.FMC_ModeRegisterDefinition = 0; // 等待SDRAM空闲 while (FMC_GetFlagStatus(FMC_BANK_SDRAM, FMC_FLAG_Busy) != RESET) ; // 配置SDRAM FMC_SDRAMCmdConfig(&FMC_SDRAMCommandStructure); // 延时5ms SDRAM_delay(1); // 预充电命令 FMC_SDRAMCommandStructure.FMC_CommandMode = FMC_Command_Mode_PALL; // 选择要控制的区域 FMC_SDRAMCommandStructure.FMC_CommandTarget = FMC_COMMAND_TARGET_BANK; FMC_SDRAMCommandStructure.FMC_AutoRefreshNumber = 1; FMC_SDRAMCommandStructure.FMC_ModeRegisterDefinition = 0; // 等待SDRAM空闲 while (FMC_GetFlagStatus(FMC_BANK_SDRAM, FMC_FLAG_Busy) != RESET) // 配置SDRAM FMC_SDRAMCmdConfig(&FMC_SDRAMCommandStructure); // 延时5ms SDRAM_delay(1); // 自动刷新配置 // 使用自动刷新 FMC_SDRAMCommandStructure.FMC_CommandMode = FMC_Command_Mode_AutoRefresh; // 选择要控制的区域 FMC_SDRAMCommandStructure.FMC_CommandTarget = FMC_COMMAND_TARGET_BANK; // 自动刷新次数 FMC_SDRAMCommandStructure.FMC_AutoRefreshNumber = 8; FMC_SDRAMCommandStructure.FMC_ModeRegisterDefinition = 0; // 等待SDRAM空闲 while (FMC_GetFlagStatus(FMC_BANK_SDRAM, FMC_FLAG_Busy) != RESET) ; // 配置SDRAM FMC_SDRAMCmdConfig(&FMC_SDRAMCommandStructure); // 寄存器配置 Reg = (uint32_t)SDRAM_MODEREG_BURST_LENGTH_2 | SDRAM_MODEREG_BURST_TYPE_SEQUENTIAL | SDRAM_MODEREG_CAS_LATENCY_3 | SDRAM_MODEREG_OPERATING_MODE_STANDARD | SDRAM_MODEREG_WRITEBURST_MODE_SINGLE; // 加载模式寄存器命令 FMC_SDRAMCommandStructure.FMC_CommandMode = FMC_Command_Mode_LoadMode; // 选择要控制的区域 FMC_SDRAMCommandStructure.FMC_CommandTarget = FMC_COMMAND_TARGET_BANK; FMC_SDRAMCommandStructure.FMC_AutoRefreshNumber = 1; // 寄存器值 FMC_SDRAMCommandStructure.FMC_ModeRegisterDefinition = Reg; // 等待SDRAM空闲 while (FMC_GetFlagStatus(FMC_BANK_SDRAM, FMC_FLAG_Busy) != RESET) ; // 配置SDRAM FMC_SDRAMCmdConfig(&FMC_SDRAMCommandStructure); // 设置刷新计数器 FMC_SetRefreshCount(1386); // 等待SDRAM空闲 while (FMC_GetFlagStatus(FMC_BANK_SDRAM, FMC_FLAG_Busy) != RESET) ; } /****************************************************************************************************** * 函 数 名: SDRAM_Init * 入口参数: 无 * 返 回 值: 无 * 函数功能: SDRAM初始化 * 说 明: 初始化FMC和SDRAM配置 *******************************************************************************************************/ void SDRAM_Init(void) { uint32_t i = 0; // 计数变量 FMC_SDRAMInitTypeDef FMC_SDRAMInitStructure; FMC_SDRAMTimingInitTypeDef FMC_SDRAMTimingInitStructure; // 开启FMC时钟 RCC_AHB3PeriphClockCmd(RCC_AHB3Periph_FMC, ENABLE); // 初始化IO口 SDRAM_GPIO_Config(); // TMRD: min=12ns (2x11.11ns) FMC_SDRAMTimingInitStructure.FMC_LoadToActiveDelay = 2; // TXSR: min=72ns (7x11.11ns) FMC_SDRAMTimingInitStructure.FMC_ExitSelfRefreshDelay = 7; // TRAS: min=42ns (4x11.11ns) FMC_SDRAMTimingInitStructure.FMC_SelfRefreshTime = 4; // TRC: min=60ns (6x11.11ns) FMC_SDRAMTimingInitStructure.FMC_RowCycleDelay = 6; // TWR: 2 Tck FMC_SDRAMTimingInitStructure.FMC_WriteRecoveryTime = 2; // TRP: 18ns => 2x11.11ns FMC_SDRAMTimingInitStructure.FMC_RPDelay = 2; // TRCD: 12ns => 2x11.11ns FMC_SDRAMTimingInitStructure.FMC_RCDDelay = 2; // 选择BANK区 FMC_SDRAMInitStructure.FMC_Bank = FMC_BANK_SDRAM; // 行地址宽度 FMC_SDRAMInitStructure.FMC_ColumnBitsNumber = FMC_ColumnBits_Number_8b; // 列地址线宽度 FMC_SDRAMInitStructure.FMC_RowBitsNumber = FMC_RowBits_Number_12b; // 数据宽度 FMC_SDRAMInitStructure.FMC_SDMemoryDataWidth = FMC_SDMemory_Width_32b; // bank数量 FMC_SDRAMInitStructure.FMC_InternalBankNumber = FMC_InternalBank_Number_4; // CAS FMC_SDRAMInitStructure.FMC_CASLatency = FMC_CAS_Latency_3; // 禁止写保护 FMC_SDRAMInitStructure.FMC_WriteProtection = FMC_Write_Protection_Disable; // 分频 FMC_SDRAMInitStructure.FMC_SDClockPeriod = FMC_SDClock_Period_2; // 突发模式 FMC_SDRAMInitStructure.FMC_ReadBurst = FMC_Read_Burst_Enable; // 读延迟 FMC_SDRAMInitStructure.FMC_ReadPipeDelay = FMC_ReadPipe_Delay_1; FMC_SDRAMInitStructure.FMC_SDRAMTimingStruct = &FMC_SDRAMTimingInitStructure; // 初始化FMC接口 FMC_SDRAMInit(&FMC_SDRAMInitStructure); // 配置SDRAM SDRAM_InitSequence(); // 初始化之后，将整个内存区写一遍数据，因为刚初始化时，第一次写数据存在不稳定的情况，所以先写一次数据。 for (i = 0; i < SDRAM_Size / 4; i++) { *(__IO uint32_t *)(SDRAM_BANK_ADDR + 4 * i) = 0x55555555; } for (i = 0; i < SDRAM_Size / 4; i++) { *(__IO uint32_t *)(SDRAM_BANK_ADDR + 4 * i) = 0x00000000; } } /****************************************************************************************************** * 函 数 名: SDRAM_Test * 入口参数: 无 * 返 回 值: SUCCESS - 成功，ERROR - 失败 * 函数功能: SDRAM测试 * 说 明: * 先以32位的数据宽度写入数据，再读取出来一一进行比较，随后以8位的数据宽度写入， * 用以验证NBL0和NBL1两个引脚的连接是否正常。 *******************************************************************************************************/ uint8_t SDRAM_Test(void) { uint32_t i = 0; // 计数变量 uint32_t ReadData = 0; // 读取到的数据 uint8_t ReadData_8b; printf("STM32F429 SDRAM测试\r\n"); printf("测试开始，以32位数据宽度写入数据...\r\n"); for (i = 0; i < SDRAM_Size / 4; i++) { *(__IO uint32_t *)(SDRAM_BANK_ADDR + 4 * i) = i; // 写入数据 } printf("写入完毕，读取数据并比较...\r\n"); for (i = 0; i < SDRAM_Size / 4; i++) { ReadData = *(__IO uint32_t *)(SDRAM_BANK_ADDR + 4 * i); // 从SDRAM读出数据 if (ReadData != i) // 检测数据，若不相等，跳出函数,返回检测失败结果。 { printf("SDRAM测试失败！！\r\n"); return ERROR; // 返回失败标志 } } printf("32位数据宽度读写通过，以8位数据宽度写入数据\r\n"); for (i = 0; i < 255; i++) { *(__IO uint8_t *)(SDRAM_BANK_ADDR + i) = i; } printf("写入完毕，读取数据并比较...\r\n"); for (i = 0; i < 255; i++) { ReadData_8b = *(__IO uint8_t *)(SDRAM_BANK_ADDR + i); if (ReadData_8b != (uint8_t)i) // 检测数据，若不相等，跳出函数,返回检测失败结果。 { printf("8位数据宽度读写测试失败！！\r\n"); printf("请检查NBL0和NBL1的连接\r\n"); return ERROR; // 返回失败标志 } } printf("8位数据宽度读写通过\r\n"); printf("SDRAM读写测试通过，系统正常\r\n"); return SUCCESS; // 返回成功标志 }