用以下代码做初始化
void LCD_FSMCConfig(void)
{
FSMC_NORSRAMInitTypeDef FSMC_NORSRAMInitStructure;
FSMC_NORSRAMTimingInitTypeDef p;
/* FSMC_Bank1_NORSRAM1 timing configuration */
p.FSMC_AddressSetupTime = 0;
p.FSMC_AddressHoldTime = 0;
p.FSMC_DataSetupTime = 1;
p.FSMC_BusTurnAroundDuration = 0;
p.FSMC_CLKDivision = 0;
p.FSMC_DataLatency = 0;
p.FSMC_AccessMode = FSMC_AccessMode_B;
/* FSMC_Bank1_NORSRAM4 configured as follows:
- Data/Address MUX = Disable
- Memory Type = SRAM
- Data Width = 16bit
- Write Operation = Enable
- Extended Mode = Disable
- Asynchronous Wait = Disable */
FSMC_NORSRAMInitStructure.FSMC_Bank = FSMC_Bank1_NORSRAM1;
FSMC_NORSRAMInitStructure.FSMC_DataAddressMux = FSMC_DataAddressMux_Disable;
FSMC_NORSRAMInitStructure.FSMC_MemoryType = FSMC_MemoryType_SRAM;
FSMC_NORSRAMInitStructure.FSMC_MemoryDataWidth = FSMC_MemoryDataWidth_16b;
FSMC_NORSRAMInitStructure.FSMC_BurstAccessMode = FSMC_BurstAccessMode_Disable;
FSMC_NORSRAMInitStructure.FSMC_WaitSignalPolarity = FSMC_WaitSignalPolarity_Low;
FSMC_NORSRAMInitStructure.FSMC_WrapMode = FSMC_WrapMode_Disable;
FSMC_NORSRAMInitStructure.FSMC_WaitSignalActive = FSMC_WaitSignalActive_BeforeWaitState;
FSMC_NORSRAMInitStructure.FSMC_WriteOperation = FSMC_WriteOperation_Enable;
FSMC_NORSRAMInitStructure.FSMC_WaitSignal = FSMC_WaitSignal_Disable;
FSMC_NORSRAMInitStructure.FSMC_ExtendedMode = FSMC_ExtendedMode_Disable;
FSMC_NORSRAMInitStructure.FSMC_WriteBurst = FSMC_WriteBurst_Disable;
FSMC_NORSRAMInitStructure.FSMC_ReadWriteTimingStruct = &p;
FSMC_NORSRAMInitStructure.FSMC_WriteTimingStruct = &p;
FSMC_NORSRAMInit(&FSMC_NORSRAMInitStructure);
/* Enable FSMC_Bank1_NORSRAM1 */
FSMC_NORSRAMCmd(FSMC_Bank1_NORSRAM1, ENABLE);
}
定义一个操作地址
#define FSMC (*(u16*)((u32)0x60000000))
然后在主程序中
while(1)
{
FSMC =0xFFFF;
FSMC = 0x0000;
}
再用示波器观察D0~D15端口上的波形，观测都周期大约是0.4微秒左右，也就是最高3MHZ的速度。比想象的要低得多得多啊，本来以为72MHZ主频下FSMC最高时钟是36MHZ，再加上一些等待周期什么的怎么着也不会太低吧，这里的p.FSMC_DataSetupTime = 1;其他的都是设置成了0，为什么速度还是这么低呢。这样折算起来操作外部SRAM的时候带宽也就最高6MB/S啊，实在是可怜的很。
疏忽了，从0XFFFF 到0X00,实际是一个波形周期对应的是2个FSMC操作，就是实际一个FSMC操作周期是0.2微秒，5MHZ左右，不过也是比想象的慢很多 |
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