我正在使用stm32h743ii微控制器,并与512mb(微米-MT48LC64M8A2P)的外部sdram接口。
我已经使用cubemx创建了初始代码,并通过参考stm32h7固件随附的示例代码来执行基本的读写测试代码。 初始化代码:
void MX_FMC_Init(void)
{
FMC_SDRAM_TimingTypeDef SdramTiming;
/** Perform the SDRAM1 memory initialization sequence
*/
hsdram1.Instance = FMC_SDRAM_DEVICE;
/* hsdram1.Init */
hsdram1.Init.SDBank = FMC_SDRAM_BANK1;
hsdram1.Init.ColumnBitsNumber = FMC_SDRAM_COLUMN_BITS_NUM_11;
hsdram1.Init.RowBitsNumber = FMC_SDRAM_ROW_BITS_NUM_13;
hsdram1.Init.MemoryDataWidth = FMC_SDRAM_MEM_BUS_WIDTH_8;
hsdram1.Init.InternalBankNumber = FMC_SDRAM_INTERN_BANKS_NUM_4;
hsdram1.Init.CASLatency = FMC_SDRAM_CAS_LATENCY_1;
hsdram1.Init.WriteProtection = FMC_SDRAM_WRITE_PROTECTION_DISABLE;
hsdram1.Init.SDClockPeriod = FMC_SDRAM_CLOCK_PERIOD_2;
hsdram1.Init.ReadBurst = FMC_SDRAM_RBURST_ENABLE;
hsdram1.Init.ReadPipeDelay = FMC_SDRAM_RPIPE_DELAY_0;
/* SdramTiming */
SdramTiming.LoadToActiveDelay = 2;
SdramTiming.ExitSelfRefreshDelay =8;
SdramTiming.SelfRefreshTime = 5;
SdramTiming.RowCycleDelay = 7;
SdramTiming.WriteRecoveryTime =3;
SdramTiming.RPDelay = 2;
SdramTiming.RCDDelay = 2;
if (HAL_SDRAM_Init(&hsdram1, &SdramTiming) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
}
所有时序参数均通过参考数据表进行配置。
问题:我正在通过将1写入4096索引到存储体1中,然后从同一内存中回读来测试读写。当我对此进行测试时,我得到的书面数据乘以256。 例如,如果我将1写入任何内存地址,则将其读回为256。
答案 0 :(得分:1)
您需要初始化SDRAM。尝试使用下一个代码(您可能需要将刷新次数更改为3,并将CAS延迟更改为)
void MX_SDRAM_InitEx(void)
{
FMC_SDRAM_CommandTypeDef Command;
__IO uint32_t tmpmrd = 0;
/* Step 1: Configure a clock configuration enable command */
Command.CommandMode = FMC_SDRAM_CMD_CLK_ENABLE;
Command.CommandTarget = FMC_SDRAM_CMD_TARGET_BANK1;
Command.AutoRefreshNumber = 1;
Command.ModeRegisterDefinition = 0;
/* Send the command */
HAL_SDRAM_SendCommand(&hsdram1, &Command, SDRAM_TIMEOUT);
/* Step 2: Insert 100 us minimum delay */
/* Inserted delay is equal to 1 ms due to systick time base unit (ms) */
HAL_Delay(1);
/* Step 3: Configure a PALL (precharge all) command */
Command.CommandMode = FMC_SDRAM_CMD_PALL;
Command.CommandTarget = FMC_SDRAM_CMD_TARGET_BANK1;
Command.AutoRefreshNumber = 1;
Command.ModeRegisterDefinition = 0;
/* Send the command */
HAL_SDRAM_SendCommand(&hsdram1, &Command, SDRAM_TIMEOUT);
/* Step 4: Configure an Auto Refresh command */
Command.CommandMode = FMC_SDRAM_CMD_AUTOREFRESH_MODE;
Command.CommandTarget = FMC_SDRAM_CMD_TARGET_BANK1;
Command.AutoRefreshNumber = 8;
Command.ModeRegisterDefinition = 0;
/* Send the command */
HAL_SDRAM_SendCommand(&hsdram1, &Command, SDRAM_TIMEOUT);
/* Step 5: Program the external memory mode register */
tmpmrd = (uint32_t)SDRAM_MODEREG_BURST_LENGTH_1 |\
SDRAM_MODEREG_BURST_TYPE_SEQUENTIAL |\
SDRAM_MODEREG_CAS_LATENCY_3 |\
SDRAM_MODEREG_OPERATING_MODE_STANDARD |\
SDRAM_MODEREG_WRITEBURST_MODE_SINGLE;
Command.CommandMode = FMC_SDRAM_CMD_LOAD_MODE;
Command.CommandTarget = FMC_SDRAM_CMD_TARGET_BANK1;
Command.AutoRefreshNumber = 1;
Command.ModeRegisterDefinition = tmpmrd;
/* Send the command */
HAL_SDRAM_SendCommand(&hsdram1, &Command, SDRAM_TIMEOUT);
/* Step 6: Set the refresh rate counter */
/* Set the device refresh rate */
HAL_SDRAM_ProgramRefreshRate(&hsdram1, REFRESH_COUNT);
}
#define REFRESH_COUNT 1386 // 1845
#define SDRAM_TIMEOUT ((uint32_t)0xFFFF)
#define SDRAM_MODEREG_BURST_LENGTH_1 ((uint16_t)0x0000)
#define SDRAM_MODEREG_BURST_LENGTH_2 ((uint16_t)0x0001)
#define SDRAM_MODEREG_BURST_LENGTH_4 ((uint16_t)0x0002)
#define SDRAM_MODEREG_BURST_LENGTH_8 ((uint16_t)0x0004)
#define SDRAM_MODEREG_BURST_TYPE_SEQUENTIAL ((uint16_t)0x0000)
#define SDRAM_MODEREG_BURST_TYPE_INTERLEAVED ((uint16_t)0x0008)
#define SDRAM_MODEREG_CAS_LATENCY_2 ((uint16_t)0x0020)
#define SDRAM_MODEREG_CAS_LATENCY_3 ((uint16_t)0x0030)
#define SDRAM_MODEREG_OPERATING_MODE_STANDARD ((uint16_t)0x0000)
#define SDRAM_MODEREG_WRITEBURST_MODE_PROGRAMMED ((uint16_t)0x0000)
#define SDRAM_MODEREG_WRITEBURST_MODE_SINGLE ((uint16_t)0x0200)