☁ Development ☁

이번에 고생 했던 EEPROM M95512 이제는 잘 동작 한다~

#define WRSR  0x01 //Write Status Register
#define WRITE 0x02 //Write to Memory Array 
#define READ  0x03 //Read from Memory Array
#define WRDI  0x04 //Write Disable
#define RDSR  0x05 //Read Status Register
#define WREN  0x06 //Write Enable
#define DUMMY 0x00 //DUMMY BYTE
  
#define EEPROM_CS_LOW()  GPIO_ResetBits(GPIOB, GPIO_Pin_0);
#define EEPROM_CS_HIGH()  GPIO_SetBits(GPIOB, GPIO_Pin_0);

void SPI_Config(void);
uint8_t SPI_SendByte(uint8_t Data);
uint8_t SPI_Flash_Read(uint16_t address);
void SPI_Flash_Write(uint16_t address, uint8_t data);

/* Includes ------------------------------------------------------------------*/
#include "stdio.h"
#include "stm32f10x.h"
#include "M95512.h"

void SPI_Config(void)
{
  SPI_InitTypeDef SPI_InitStructure;
  GPIO_InitTypeDef GPIO_InitStructure;

  SPI_Cmd(SPI1, DISABLE); 
  SPI_I2S_DeInit(SPI1);
  
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1 | RCC_APB2Periph_AFIO, DISABLE); 
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
  GPIO_Init(GPIOA, &GPIO_InitStructure); 
      
  /* Enable SPI clock, SPI1 */ 
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_SPI1, ENABLE);
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; // 50 MHz
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
  
  // Configure CS pin as output floating
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  /* SPI configuration -------------------------------------------------------*/
  EEPROM_CS_HIGH();
  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
  SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
  SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
  SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;
  SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
  SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_8;
  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
  SPI_InitStructure.SPI_CRCPolynomial = 7;
  SPI_Init(SPI1, &SPI_InitStructure);
  SPI_Cmd(SPI1, ENABLE); 
}

uint8_t SPI_SendByte(uint8_t Data)
{
  while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
  SPI_I2S_SendData(SPI1, Data); 
  while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
  return SPI_I2S_ReceiveData(SPI1);
}

static void M95512_WREN(void)
{//0x06 Write Enable
  EEPROM_CS_LOW(); 
  SPI_SendByte(WREN); 
  EEPROM_CS_HIGH();
}

static void M95512_WRDI(void)
{//0x04 Write Disable
  EEPROM_CS_LOW(); 
  SPI_SendByte(WRDI); 
  EEPROM_CS_HIGH();
}

static void M95512_RDSR(void)
{//0x05 Read Status Register
  unsigned char data_H, data_L;
  unsigned int data = 0;
  
  EEPROM_CS_LOW();  
  SPI_SendByte(RDSR); 
//  data_H = SPI_ReadByte();  
//  data_L = SPI_ReadByte();
  EEPROM_CS_HIGH();
  data = (data_H << 1) + (data_L << 7);     
}

static void M95512_WRSR(unsigned char reg)
{//0x01 Write Status Register
  EEPROM_CS_LOW();  
  SPI_SendByte(WRSR);
  SPI_SendByte(reg);  
  EEPROM_CS_HIGH(); 
}

uint8_t SPI_Flash_Read(uint16_t address)
{
  uint8_t data;
  
   EEPROM_CS_LOW();
  SPI_SendByte(READ);
  SPI_SendByte((address & 0xFF00) >> 8);
  SPI_SendByte(address & 0xFF);
  data = SPI_SendByte(DUMMY);
  EEPROM_CS_HIGH();
  return data;
} 
   
void SPI_Flash_Write(uint16_t address, uint8_t data)
{
  M95512_WREN();
 
  EEPROM_CS_LOW();
  SPI_SendByte(WRITE);          // Send SPI instruction 
  SPI_SendByte((address & 0xFF00) >> 8);  // Send SPI address MSB
  SPI_SendByte(address & 0xFF);           // Send SPI address LSB
  SPI_SendByte(data);           // Send SPI Write data(Byte)
  EEPROM_CS_HIGH();
}

위와 같이 하여 놓고

main에서

  SPI_Flash_Write(0x0000,0x11);
  SPI1_READ_DATA = SPI_Flash_Read(0x0000);

사용하면 데이타가 잘 들어 온다~

 

뭐 이런 Story죠.

그럼 이때! SWI_C_Handler에 잘 도달 할 수 있도록 수로를 잘 터왔으니까, SWI_C_Handler만 잘 구현하면 됩니다. 잘 보세요.

논리 시프트와 산술 시프트의 차이

논리 시프트 역시 비트를 이동하는 연산이나, 산술 시프트와의 제일 큰 차이는 부호비트(sign bit)가 보존되지 않는다는 것이다. 따라서 부호가 정의된 16비트 정수(signed integer)에서 연산의 결과값이100 0000₍₂₎=32768₍₁₀₎ 이상의 범위를 넘어갈 경우 부호가 바뀌는 경우가 발생한다.