基本说明
STM32访问外部存储器是需要配置FSMC的相关函数,在STM32固件库函数说明的中文翻译版中并没有这部分的说明,因此需要参考库函数的相关说明和库中自带的例程。
以下内容来自AN2784应用笔记:
2 与非总线复用模式的异步16位NOR闪存接口
2.1
FSMC配置
控制一个NOR闪存存储器,需要FSMC提供下述功能:
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选择合适的存储块映射NOR闪存存储器:共有4个独立的存储块可以用于与NOR闪存、SRAM和PSRAM存储器接口,每个存储块都有一个专用的片选管脚。
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使用或禁止地址/数据总线的复用功能。
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选择所用的存储器类型:NOR闪存、SRAM或PSRAM。
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定义外部存储器的数据总线宽度:8或16位。
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使用或关闭同步NOR闪存存储器的突发访问模式。
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配置等待信号的使用:开启或关闭,极性设置,时序配置。
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使用或关闭扩展模式:扩展模式用于访问那些具有不同读写操作时序的存储器。
因为NOR闪存/SRAM控制器可以支持异步和同步存储器,用户只须根据存储器的参数配置使用到的参数。
FSMC提供了一些可编程的参数,可以正确地与外部存储器接口。依存储器类型的不同,有些参数是不需要的。
当使用一个外部异步存储器时,用户必须按照存储器的数据手册给出的时序数据,计算和设置下列参数:
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ADDSET:地址建立时间
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ADDHOLD:地址保持时间
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DATAST:数据建立时间
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ACCMOD:访问模式 这个参数允许 FSMC可以灵活地访问多种异步的静态存储器。共有4种扩展模式允许以不同的时序分别读写存储器。 在扩展模式下,FSMC_BTR用于配置读操作,FSMC_BWR用于配置写操作。(译注:如果读时序与写时序相同,只须使用FSMC_BTR即可。)
如果使用了同步的存储器,用户必须计算和设置下述参数:
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CLKDIV:时钟分频系数
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DATLAT:数据延时
如果存储器支持的话,NOR闪存的读操作可以是同步的,而写操作仍然是异步的。
当对一个同步的NOR闪存编程时,存储器会自动地在同步与异步之间切换;因此,必须正确地设置所有的参数
程序分析
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- p.FSMC_AddressSetupTime = 0x05;
- p.FSMC_AddressHoldTime = 0x00;
- p.FSMC_DataSetupTime = 0x07;
- p.FSMC_BusTurnAroundDuration = 0x00;
- p.FSMC_CLKDivision = 0x00;
- p.FSMC_DataLatency = 0x00;
- p.FSMC_AccessMode = FSMC_AccessMode_B;
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- FSMC_NORSRAMInitStructure.FSMC_Bank = FSMC_Bank1_NORSRAM2;
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- FSMC_NORSRAMInitStructure.FSMC_DataAddressMux = FSMC_DataAddressMux_Disable;
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- FSMC_NORSRAMInitStructure.FSMC_MemoryType = FSMC_MemoryType_NOR;
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- FSMC_NORSRAMInitStructure.FSMC_MemoryDataWidth = FSMC_MemoryDataWidth_16b;
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- FSMC_NORSRAMInitStructure.FSMC_BurstAccessMode = FSMC_BurstAccessMode_Disable;
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- FSMC_NORSRAMInitStructure.FSMC_WaitSignalPolarity = FSMC_WaitSignalPolarity_Low;
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- FSMC_NORSRAMInitStructure.FSMC_WrapMode = FSMC_WrapMode_Disable;
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- FSMC_NORSRAMInitStructure.FSMC_WaitSignalActive = FSMC_WaitSignalActive_BeforeWaitState;
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- FSMC_NORSRAMInitStructure.FSMC_WriteOperation = FSMC_WriteOperation_Enable;
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- FSMC_NORSRAMInitStructure.FSMC_WaitSignal = FSMC_WaitSignal_Disable;
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- FSMC_NORSRAMInitStructure.FSMC_ExtendedMode = FSMC_ExtendedMode_Disable;
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- FSMC_NORSRAMInitStructure.FSMC_AsyncWait = FSMC_AsyncWait_Disable;
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- FSMC_NORSRAMInitStructure.FSMC_WriteBurst = FSMC_WriteBurst_Disable;
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- FSMC_NORSRAMInitStructure.FSMC_ReadWriteTimingStruct = &p;
- FSMC_NORSRAMInitStructure.FSMC_WriteTimingStruct = &p;
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- FSMC_NORSRAMInit(&FSMC_NORSRAMInitStructure);
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- FSMC_NORSRAMCmd(FSMC_Bank1_NORSRAM2, ENABLE);
- }
实际例程
以下例程来自 stm3210e_eval_fsmc_nor.c具体信息参加固件库中源文件。
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- #include "stm3210e_eval_fsmc_nor.h"
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- #define Bank1_NOR2_ADDR ((uint32_t)0x64000000)
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- #define BlockErase_Timeout ((uint32_t)0x00A00000)
- #define ChipErase_Timeout ((uint32_t)0x30000000)
- #define Program_Timeout ((uint32_t)0x00001400)
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- #define ADDR_SHIFT(A) (Bank1_NOR2_ADDR + (2 * (A)))
- #define NOR_WRITE(Address, Data) (*(__IO uint16_t *)(Address) = (Data))
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- void NOR_Init(void)
- {
- FSMC_NORSRAMInitTypeDef FSMC_NORSRAMInitStructure;
- FSMC_NORSRAMTimingInitTypeDef p;
- GPIO_InitTypeDef GPIO_InitStructure;
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOE |
- RCC_APB2Periph_GPIOF | RCC_APB2Periph_GPIOG, ENABLE);
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- 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);
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- 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);
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3 | GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_6;
- GPIO_Init(GPIOE, &GPIO_InitStructure);
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- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_5;
- GPIO_Init(GPIOD, &GPIO_InitStructure);
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- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
- GPIO_Init(GPIOG, &GPIO_InitStructure);
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- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
- GPIO_Init(GPIOD, &GPIO_InitStructure);
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- p.FSMC_AddressSetupTime = 0x02;
- p.FSMC_AddressHoldTime = 0x00;
- p.FSMC_DataSetupTime = 0x05;
- p.FSMC_BusTurnAroundDuration = 0x00;
- p.FSMC_CLKDivision = 0x00;
- p.FSMC_DataLatency = 0x00;
- p.FSMC_AccessMode = FSMC_AccessMode_B;
- FSMC_NORSRAMInitStructure.FSMC_Bank = FSMC_Bank1_NORSRAM2;
- FSMC_NORSRAMInitStructure.FSMC_DataAddressMux = FSMC_DataAddressMux_Disable;
- FSMC_NORSRAMInitStructure.FSMC_MemoryType = FSMC_MemoryType_NOR;
- FSMC_NORSRAMInitStructure.FSMC_MemoryDataWidth = FSMC_MemoryDataWidth_16b;
- FSMC_NORSRAMInitStructure.FSMC_BurstAccessMode = FSMC_BurstAccessMode_Disable;
- FSMC_NORSRAMInitStructure.FSMC_AsynchronousWait = FSMC_AsynchronousWait_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);
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- FSMC_NORSRAMCmd(FSMC_Bank1_NORSRAM2, ENABLE);
- }
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- void NOR_ReadID(NOR_IDTypeDef* NOR_ID)
- {
- NOR_WRITE(ADDR_SHIFT(0x0555), 0x00AA);
- NOR_WRITE(ADDR_SHIFT(0x02AA), 0x0055);
- NOR_WRITE(ADDR_SHIFT(0x0555), 0x0090);
- NOR_ID->Manufacturer_Code = *(__IO uint16_t *) ADDR_SHIFT(0x0000);
- NOR_ID->Device_Code1 = *(__IO uint16_t *) ADDR_SHIFT(0x0001);
- NOR_ID->Device_Code2 = *(__IO uint16_t *) ADDR_SHIFT(0x000E);
- NOR_ID->Device_Code3 = *(__IO uint16_t *) ADDR_SHIFT(0x000F);
- }
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- NOR_Status NOR_EraseBlock(uint32_t BlockAddr)
- {
- NOR_WRITE(ADDR_SHIFT(0x0555), 0x00AA);
- NOR_WRITE(ADDR_SHIFT(0x02AA), 0x0055);
- NOR_WRITE(ADDR_SHIFT(0x0555), 0x0080);
- NOR_WRITE(ADDR_SHIFT(0x0555), 0x00AA);
- NOR_WRITE(ADDR_SHIFT(0x02AA), 0x0055);
- NOR_WRITE((Bank1_NOR2_ADDR + BlockAddr), 0x30);
- return (NOR_GetStatus(BlockErase_Timeout));
- }
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- NOR_Status NOR_EraseChip(void)
- {
- NOR_WRITE(ADDR_SHIFT(0x0555), 0x00AA);
- NOR_WRITE(ADDR_SHIFT(0x02AA), 0x0055);
- NOR_WRITE(ADDR_SHIFT(0x0555), 0x0080);
- NOR_WRITE(ADDR_SHIFT(0x0555), 0x00AA);
- NOR_WRITE(ADDR_SHIFT(0x02AA), 0x0055);
- NOR_WRITE(ADDR_SHIFT(0x0555), 0x0010);
- return (NOR_GetStatus(ChipErase_Timeout));
- }
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- NOR_Status NOR_WriteHalfWord(uint32_t WriteAddr, uint16_t Data)
- {
- NOR_WRITE(ADDR_SHIFT(0x0555), 0x00AA);
- NOR_WRITE(ADDR_SHIFT(0x02AA), 0x0055);
- NOR_WRITE(ADDR_SHIFT(0x0555), 0x00A0);
- NOR_WRITE((Bank1_NOR2_ADDR + WriteAddr), Data);
- return (NOR_GetStatus(Program_Timeout));
- }
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- NOR_Status NOR_WriteBuffer(uint16_t* pBuffer, uint32_t WriteAddr, uint32_t NumHalfwordToWrite)
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- NOR_Status status = NOR_ONGOING;
- do
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- status = NOR_WriteHalfWord(WriteAddr, *pBuffer++);
- WriteAddr = WriteAddr + 2;
- NumHalfwordToWrite--;
- }
- while((status == NOR_SUCCESS) && (NumHalfwordToWrite != 0));
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- return (status);
- }
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- NOR_Status NOR_ProgramBuffer(uint16_t* pBuffer, uint32_t WriteAddr, uint32_t NumHalfwordToWrite)
- {
- uint32_t lastloadedaddress = 0x00;
- uint32_t currentaddress = 0x00;
- uint32_t endaddress = 0x00;
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- currentaddress = WriteAddr;
- endaddress = WriteAddr + NumHalfwordToWrite - 1;
- lastloadedaddress = WriteAddr;
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- NOR_WRITE(ADDR_SHIFT(0x00555), 0x00AA);
- NOR_WRITE(ADDR_SHIFT(0x02AA), 0x0055);
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- NOR_WRITE(ADDR_SHIFT(WriteAddr), 0x0025);
- NOR_WRITE(ADDR_SHIFT(WriteAddr), (NumHalfwordToWrite - 1));
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- while(currentaddress <= endaddress)
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- lastloadedaddress = currentaddress;
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- NOR_WRITE(ADDR_SHIFT(currentaddress), *pBuffer++);
- currentaddress += 1;
- }
- NOR_WRITE(ADDR_SHIFT(lastloadedaddress), 0x29);
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- return(NOR_GetStatus(Program_Timeout));
- }
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- uint16_t NOR_ReadHalfWord(uint32_t ReadAddr)
- {
- NOR_WRITE(ADDR_SHIFT(0x00555), 0x00AA);
- NOR_WRITE(ADDR_SHIFT(0x002AA), 0x0055);
- NOR_WRITE((Bank1_NOR2_ADDR + ReadAddr), 0x00F0 );
- return (*(__IO uint16_t *)((Bank1_NOR2_ADDR + ReadAddr)));
- }
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- void NOR_ReadBuffer(uint16_t* pBuffer, uint32_t ReadAddr, uint32_t NumHalfwordToRead)
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- NOR_WRITE(ADDR_SHIFT(0x0555), 0x00AA);
- NOR_WRITE(ADDR_SHIFT(0x02AA), 0x0055);
- NOR_WRITE((Bank1_NOR2_ADDR + ReadAddr), 0x00F0);
- for(; NumHalfwordToRead != 0x00; NumHalfwordToRead--)
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- *pBuffer++ = *(__IO uint16_t *)((Bank1_NOR2_ADDR + ReadAddr));
- ReadAddr = ReadAddr + 2;
- }
- }
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- NOR_Status NOR_ReturnToReadMode(void)
- {
- NOR_WRITE(Bank1_NOR2_ADDR, 0x00F0);
- return (NOR_SUCCESS);
- }
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- NOR_Status NOR_Reset(void)
- {
- NOR_WRITE(ADDR_SHIFT(0x00555), 0x00AA);
- NOR_WRITE(ADDR_SHIFT(0x002AA), 0x0055);
- NOR_WRITE(Bank1_NOR2_ADDR, 0x00F0);
- return (NOR_SUCCESS);
- }
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- NOR_Status NOR_GetStatus(uint32_t Timeout)
- {
- uint16_t val1 = 0x00, val2 = 0x00;
- NOR_Status status = NOR_ONGOING;
- uint32_t timeout = Timeout;
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- while((GPIO_ReadInputDataBit(GPIOD, GPIO_Pin_6) != RESET) && (timeout > 0))
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- timeout--;
- }
- timeout = Timeout;
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- while((GPIO_ReadInputDataBit(GPIOD, GPIO_Pin_6) == RESET) && (timeout > 0))
- {
- timeout--;
- }
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- while((Timeout != 0x00) && (status != NOR_SUCCESS))
- {
- Timeout--;
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- val1 = *(__IO uint16_t *)(Bank1_NOR2_ADDR);
- val2 = *(__IO uint16_t *)(Bank1_NOR2_ADDR);
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- if((val1 & 0x0040) == (val2 & 0x0040))
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- return NOR_SUCCESS;
- }
- if((val1 & 0x0020) != 0x0020)
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- status = NOR_ONGOING;
- }
- val1 = *(__IO uint16_t *)(Bank1_NOR2_ADDR);
- val2 = *(__IO uint16_t *)(Bank1_NOR2_ADDR);
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- if((val1 & 0x0040) == (val2 & 0x0040))
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- return NOR_SUCCESS;
- }
- else if((val1 & 0x0020) == 0x0020)
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- return NOR_ERROR;
- }
- }
- if(Timeout == 0x00)
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- status = NOR_TIMEOUT;
- }
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- return (status);
- }
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本文转自emouse博客园博客,原文链接:http://www.cnblogs.com/emouse/archive/2011/01/05/2198192.html,如需转载请自行联系原作者