FMC—读写SDRAM-W9825G6KH-6
FMC—读写SDRAM-W9825G6KH-6一些注意事项，后面直接看代码
1、W9825G6KH是行地址(row)13bit，列地址(column)9bit，数据16位，4banks，总共32M字节，166MHz/CL3 or 133MHz/CL2，0°C ~ 70°C。
2、可配置为SDRAM1或SDRAM2，SDRAM1地址为0xC0000000，SDRAM2地址为0xD0000000。
3、配置为SDRAM1或2，需与后面配置的自刷新BANK号需一致，否则读写不到数据。
4、地址宽度要配置正确，否则读写会卡死。
5、配置的SDRAM时钟为2分频，即216M/2=108M，一个周期为1000/109=9.259ns==9.3ns。
缩写解析：
CL ＝CAS Latency
tRSC =Mode register Set Cycle Time, 加载模式寄存器命令后的延迟
tXSR =Exit self refresh to ACTIVE command, 自刷新命令后的延迟
tRAS =Active to precharge Command Period, 自刷新时间
tRC =Ref/Active to Ref/Active Command Period, 行循环延迟
tWR ＝Write Recovery Time，恢复延迟
tRP = Precharge to Active Command Period, 行预充电延迟
tRCD= Active to Read/Write Command Delay Time, 行到列延迟
SdramTiming.LoadToActiveDelay = 2; = tMRD或tRSC, = 2 tCK, 即最少2个时钟周期
SdramTiming.ExitSelfRefreshDelay = 8; = tXSR, = 72ns, 此处8*9.3＝74ns。
SdramTiming.SelfRefreshTime = 5; = tRAS, = 42ns, 此处5*9.3＝46.5ns。
SdramTiming.RowCycleDelay = 7; = tRC, = 60ns, 此处7*9.3＝65ns。
SdramTiming.WriteRecoveryTime = 2; ＝tWR, ＝2 tCK，即最少2个时钟周期
SdramTiming.RPDelay = 2; = tRP, = 15ns，此处2*9.3＝18ns。
SdramTiming.RCDDelay = 2; ＝ tRCD, = 15ns，此处2*9.3＝18ns。
配置上电时序，需在SDRAM配置后再调用。
void SDRAM_Init_Sequence(uint32_t RefreshCount)
{
__IO uint32_t tmpmrd = 0;
FMC_SDRAM_CommandTypeDef Command;
/* 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(100);
/* 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, RefreshCount);
}
CUBEMX配置
时序表
测试结果
工程代码：
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