初始化和使用都比较简单
void FSMC_SRAM_Init(void) { FSMC_NORSRAMInitTypeDef FSMC_NORSRAMInitStructure; FSMC_NORSRAMTimingInitTypeDef p; GPIO_InitTypeDef GPIO_InitStructure; RCC_AHBPeriphClockCmd(RCC_AHBPeriph_FSMC, ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOG | RCC_APB2Periph_GPIOE | RCC_APB2Periph_GPIOF, ENABLE); /*-- GPIO Configuration ------------------------------------------------------*/ /* SRAM Data lines configuration */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 | GPIO_Pin_14 | GPIO_Pin_15; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOD, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7 | GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 | GPIO_Pin_11 | GPIO_Pin_12 | GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15; GPIO_Init(GPIOE, &GPIO_InitStructure); /* SRAM Address lines configuration */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3 | GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_12 | GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15; GPIO_Init(GPIOF, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3 | GPIO_Pin_4 | GPIO_Pin_5; GPIO_Init(GPIOG, &GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11 | GPIO_Pin_12 | GPIO_Pin_13; GPIO_Init(GPIOD, &GPIO_InitStructure); /* NOE and NWE configuration */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 |GPIO_Pin_5; GPIO_Init(GPIOD, &GPIO_InitStructure); /* NE3 configuration */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10; GPIO_Init(GPIOG, &GPIO_InitStructure); /* NBL0, NBL1 configuration */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1; GPIO_Init(GPIOE, &GPIO_InitStructure); /* * PG9 接到了 NORFLASH 的 CE 端，为了不让 NORFLASH的信号 影响到 SRAM * 这里先让 CE = 1 ,即 PG9 = 1 ,不然 SRAM 会测试不成功. * 或者在硬件设计时，NORFLASH 的 CE 管脚 上拉下. */ //GPIO_InitTypeDef GPIO_InitStructure; //GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; //GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //GPIO_Init(GPIOG, &GPIO_InitStructure); //GPIO_SetBits(GPIOG,GPIO_Pin_9); //片选已上拉
/*-- FSMC Configuration ------------------------------------------------------*/ #if 1 p.FSMC_AddressSetupTime = 0; p.FSMC_AddressHoldTime = 0; p.FSMC_DataSetupTime = 2; p.FSMC_BusTurnAroundDuration = 0; p.FSMC_CLKDivision = 0; p.FSMC_DataLatency = 0; #elif 0 p.FSMC_AddressSetupTime = 15; p.FSMC_AddressHoldTime = 15; p.FSMC_DataSetupTime = 15; p.FSMC_BusTurnAroundDuration = 15; p.FSMC_CLKDivision = 8; p.FSMC_DataLatency = 15; #endif p.FSMC_AccessMode = FSMC_AccessMode_A; FSMC_NORSRAMInitStructure.FSMC_Bank = FSMC_Bank1_NORSRAM3; 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_SRAM Bank */ FSMC_NORSRAMCmd(FSMC_Bank1_NORSRAM3, ENABLE); }
使用就用绝对定位
__attribute__((at(addr)))
比如：
unsigned char buffer[10000] __attribute__((at(0x6800000)))，即把数据buffer的地址定位到0x6800000