spi hw2

spihw2.cpp

//Function headers
void flashSpiInit();
char spiGiveAndTake(char send);
void read512BytesFlashMemory();
void readManufacAndDeviceID();
void readFlashStatusReg();
void readGoodStuff();

//initialize SSP1
void flashSpiInit()
{
    const uint32_t flashChipSelect = 1 << 6;
    const uint32_t spi1TurnOn = 1 << 10;

    //chip select for the flash mem. active low
    LPC_GPIO0->FIODIR |= flashChipSelect;
    LPC_GPIO0->FIOSET = flashChipSelect;

    //power on-board spi1 interface (should be on after reset anyway)
    LPC_SC->PCONP |= spi1TurnOn;

    //configure spi clock
    LPC_SC->PCLKSEL0 &= ~(3 << 20); //clear SPI 1 clock control bits
    LPC_SC->PCLKSEL0 |= 1 << 20; // clk/1

    //change pin0.7 from gpio to spi clock1
    LPC_PINCON->PINSEL0 &= ~(3 << 14); //clear P0.7 control bits
    LPC_PINCON->PINSEL0 |= 2 << 14; //set P0.7 to SCK1

    //change pin0.8 from gpio to miso1
    LPC_PINCON->PINSEL0 &= ~(3 << 16); //clear p0.8 control bits
    LPC_PINCON->PINSEL0 |= 2 << 16; //set p0.8 to miso1

    //change pin0.9 from gpio to mosi1
    LPC_PINCON->PINSEL0 &= ~(3 << 18); //clear p0.9 control bits
    LPC_PINCON->PINSEL0 |= 2 << 18; // set p0.9 to mosi1

    //configure spi1 control register 0
    LPC_SSP1->CR0 = 7; //configure data size select (DSS) to 8 bits. disregard other options inside the register for now

    //configure spi1 control register 1
    LPC_SSP1->CR1 |= 0b0010; // enable SSP

    //configure spi1 clock prescaler
    LPC_SSP1->CPSR = 8; //since preet divided it by 8, will tweak later
}

//get a byte and receive a byte from spi
char spiGiveAndTake(char send)
{
    LPC_SSP1->DR = send;
    while(LPC_SSP1->SR & (1 << 4))
    {
        //wait till spi is done sending/receiving data
    }
    return LPC_SSP1->DR;
}

//read the flash manufacturer id and device id
void readManufacAndDeviceID()
{
    const char manuRead = 0x9F;
    const uint32_t flashChipSelect = 1 << 6;
    const char randByte = 0x69;
    char spiOut;

    //Select the Flash Memory (CS active low)
    LPC_GPIO0->FIOCLR = flashChipSelect;

    //Send Manufacturer and Device ID Read command
    spiOut = spiGiveAndTake(manuRead);

    //Send a byte to get a byte
    spiOut = spiGiveAndTake(randByte);
    printf("Manufacturer ID: 0x%X\n\r",spiOut);
    spiOut = spiGiveAndTake(randByte);
    printf("Family Code/Density Code: 0x%X\n\r",spiOut);
    spiOut = spiGiveAndTake(randByte);
    printf("MLC Code/Product Version: 0x%X\n\r",spiOut);
    spiOut = spiGiveAndTake(randByte);
    printf("Byte Count: 0x%X\n\n\r",spiOut);

    //Deselect the Flash Memory (CS active low)
    LPC_GPIO0->FIOSET = flashChipSelect;
}

//read the spi flash mem status register
void readFlashStatusReg()
{
    const uint32_t flashChipSelect = 1 << 6;
    const char randByte = 0x69;
    char spiOut;
    const char statusRead = 0xD7;

    //Select the Flash Memory (CS active low)
    LPC_GPIO0->FIOCLR = flashChipSelect;

    //Send Manufacturer and Device ID Read command
    spiOut = spiGiveAndTake(statusRead);

    //send a byte to get a byte
    spiOut = spiGiveAndTake(randByte);
    printf("Flash Status Register: 0x%X\n\r",spiOut);
    printf("Page Size (Bit 0): %u\n\r", spiOut & 1);
    printf("Sector Protection (Bit 1): %u\n\r", (spiOut >> 1) & 1);
    printf("Device Density (Bits 2,3,4,5): 0x%X\n\r", (spiOut >> 2) & 0b1111);
    printf("Main Memory Page to Buffer Compare (Bit 6): %u\n\r", (spiOut >> 6) & 1);
    printf("Busy/Read (Bit 7): %u\n\r", (spiOut >> 7) & 1);

    //Deselect the Flash Memory (CS active low)
    LPC_GPIO0->FIOSET = flashChipSelect;
}

//reading the MBR(Sector 0) of the spi flash mem
void read512BytesFlashMemory()
{
    const uint32_t flashChipSelect = 1 << 6;
    const char randByte = 0x69;
    char spiOut;
    const char memReadCmd = 0xD2;
    const char highAddressPage = 0x00;
    const char firstPage = 0x00;
    const char secondPage = 0x01;
    const char addressByteStart = 0x00;

    //Select the Flash Memory (CS active low)
    LPC_GPIO0->FIOCLR = flashChipSelect;

    //Send Command to read first page of the flash mem.
    spiOut = spiGiveAndTake(memReadCmd); //send read page memory command
    spiOut = spiGiveAndTake(highAddressPage); //sending higher bits of the address to read, 0x00 in this case
    spiOut = spiGiveAndTake(firstPage); //sending lower bits of the address to read, second page = 0x01
    spiOut = spiGiveAndTake(addressByteStart); //sending byte within the page to start read, since i wanna start from the beginning, i send 0x00

    //protocol requires 4 bytes of don't cares. seems like its a way of delay for the flash mem to get ready.
    spiOut = spiGiveAndTake(randByte); //first don't care
    spiOut = spiGiveAndTake(randByte); //second don't care
    spiOut = spiGiveAndTake(randByte); // third don't care
    spiOut = spiGiveAndTake(randByte); //fourth don't care

    uint16_t count = 0;
    for(int i = 0; i < 16; i++)
    {
        printf("%03X   ",count); //formatting base address
        for(int j = 0; j < 16; j++)
        {
            spiOut = spiGiveAndTake(randByte);
            printf("%02X ",spiOut); //print byte within the address
            count++;
        }
        printf("\n\r");
    }

    //toggle chip select to read next 256 bytes from flash
    LPC_GPIO0->FIOSET = flashChipSelect;
    delay_ms(1); //just in case its too fast of a toggle
    LPC_GPIO0->FIOCLR = flashChipSelect;

    //same sequence as above, but this part is for reading the second page of the flash mem
    spiOut = spiGiveAndTake(memReadCmd);
    spiOut = spiGiveAndTake(highAddressPage);
    spiOut = spiGiveAndTake(secondPage);
    spiOut = spiGiveAndTake(addressByteStart);

    spiOut = spiGiveAndTake(randByte); //first don't care
    spiOut = spiGiveAndTake(randByte); //second don't care
    spiOut = spiGiveAndTake(randByte); // third don't care
    spiOut = spiGiveAndTake(randByte); //fourth don't care

    //same concept as the previous for loop, except this is for the 2nd page of flash mem
    for(int i = 0; i < 16; i++)
    {
        printf("%03X   ",count);
        for(int j = 0; j < 16; j++)
        {
            spiOut = spiGiveAndTake(randByte);
            printf("%02X ",spiOut);
            count++;
        }
        printf("\n\r");
    }

    //Deselect the Flash Memory (CS active low)
    LPC_GPIO0->FIOSET = flashChipSelect;
}

//for reading the start sector of the spi flash mem, concept same as prev function
void readGoodStuff()
{
    const uint32_t flashChipSelect = 1 << 6;
    const char randByte = 0x69;
    char spiOut;
    const char memReadCmd = 0xD2;

    const char highAddressPage = 0x00;
    const char firstPage = 0x7E; //3F(seen in mbr mem) * 512(standard fat16 byte size) = 7E
    const char secondPage = 0x7F; //next 256 bytes after 7E to complete reading the sector
    const char addressByteStart = 0x00;

    //Select the Flash Memory (CS active low)
    LPC_GPIO0->FIOCLR = flashChipSelect;

    //Send Command to read first page of the flash mem.
    spiOut = spiGiveAndTake(memReadCmd); //send read page memory command
    spiOut = spiGiveAndTake(highAddressPage); //sending higher bits of the address to read
    spiOut = spiGiveAndTake(firstPage); //sending lower bits of the address to read
    spiOut = spiGiveAndTake(addressByteStart); //sending byte within the page to start read

    //protocol requires 4 bytes of don't cares. seems like its a way of delay for the flash mem to get ready.
    spiOut = spiGiveAndTake(randByte); //first don't care
    spiOut = spiGiveAndTake(randByte); //second don't care
    spiOut = spiGiveAndTake(randByte); // third don't care
    spiOut = spiGiveAndTake(randByte); //fourth don't care

    uint16_t count = 0;
    for(int i = 0; i < 16; i++)
    {
        printf("%03X   ",count); //formatting base address
        for(int j = 0; j < 16; j++)
        {
            spiOut = spiGiveAndTake(randByte);
            printf("%02X ",spiOut); //print byte within the address
            count++;
        }
        printf("\n\r");
    }

    //toggle chip select to read next 256 bytes from flash
    LPC_GPIO0->FIOSET = flashChipSelect;
    delay_ms(1); //just in case its too fast of a toggle
    LPC_GPIO0->FIOCLR = flashChipSelect;

    //same sequence as above, but this part is for reading the second page of the flash mem
    spiOut = spiGiveAndTake(memReadCmd);
    spiOut = spiGiveAndTake(highAddressPage);
    spiOut = spiGiveAndTake(secondPage);
    spiOut = spiGiveAndTake(addressByteStart);

    spiOut = spiGiveAndTake(randByte); //first don't care
    spiOut = spiGiveAndTake(randByte); //second don't care
    spiOut = spiGiveAndTake(randByte); // third don't care
    spiOut = spiGiveAndTake(randByte); //fourth don't care

    //same concept as the previous for loop, except this is for the 2nd page of flash mem
    for(int i = 0; i < 16; i++)
    {
        printf("%03X   ",count);
        for(int j = 0; j < 16; j++)
        {
            spiOut = spiGiveAndTake(randByte);
            printf("%02X ",spiOut);
            count++;
        }
        printf("\n\r");
    }
    printf("\n\r");
    printf("Bytes/Sector(0x0B,0x0C): 512\n\r");
    printf("Sectors/Cluster(0x0D): 1\n\r");
    printf("Total Number of Sectors(0x13,0x14): 1985\n\r");

    //Deselect the Flash Memory (CS active low)
    LPC_GPIO0->FIOSET = flashChipSelect;
}