I’m trying to do an SPI multibyte transaction with CRC.

For I2C

• you sent the slave address -> register address -> first data -> first CRC -> second data -> second CRC -> third data -> third crc and so on
• first CRC is calculated using slave address, register address and first data
• second CRC is calculated using second data
• third CRC is calculated using third data
• and so on for fourth, fifth, … CRC

I tried doing the same way for SPI but it didn’t work.

From the image below, I tried setting IO_SPIMODE = 0, remove packet length from my code, and set AI = 1 and it still didn’t work.

SPI Write Transaction Example
SPI Table

1. Change SPI_MODE = 0 and AI = 0 as Im doing multi byte write
2. I write 0xFA, 0xEF, 0xCD, and 0x9F to reg address of 0x125, assuming SPI auto increment the reg address
3. Change SPI_MODE = 1 and AI = 1 as Im doing single byte read
4. I read from 0x125 and 0x126 reg address and it’s not right.

My code:

`uint8_t r_pmic_prot_spi_multiple_write(uint16_t w_addr, uint8_t w_data1, uint8_t w_data2, uint8_t w_data3, uint8_t w_data4) {
    uint8_t crc_data1 = 0;
    uint8_t crc_data2 = 0;
    uint8_t crc_data3 = 0;
    uint8_t crc_data4 = 0;

    P4_BIT2_PSSL = 0;
    g_spi_csi10_tx_done = 0;

    status_write = 0x00;


    crc_data = 0x00;

    multi_write_data_crc[0] = 0x40 + (w_addr >> 8); // first byte
    multi_write_data_crc[1] = (w_addr & 0xFF); // second byte

    crc_data = r_calculate_i2c_crc(crc_data, multi_write_data_crc[0]);
    crc_data = r_calculate_i2c_crc(crc_data, multi_write_data_crc[1]);

    multi_write_data_crc[2] = w_data1; //first data
    crc_data1 = r_calculate_i2c_crc(crc_data, multi_write_data_crc[2]);
    multi_write_data_crc[3] = crc_data1; // first crc

    crc_data = 0;
    multi_write_data_crc[4] = w_data2; // second data
    crc_data2 = r_calculate_i2c_crc(crc_data, multi_write_data_crc[4]);
    multi_write_data_crc[5] = crc_data2; // second data

    crc_data = 0;
    multi_write_data_crc[6] = w_data3; 
    crc_data3 = r_calculate_i2c_crc(crc_data, multi_write_data_crc[6]);
    multi_write_data_crc[7] = crc_data3;

    crc_data = 0;
    multi_write_data_crc[8] = w_data4;
    crc_data4 = r_calculate_i2c_crc(crc_data, multi_write_data_crc[8]);
    multi_write_data_crc[9] = crc_data4;

    status_write = R_CSI10_Send_Receive(multi_write_data_crc, sizeof(multi_write_data_crc), multi_read_data_crc);

    while (g_spi_csi10_tx_done == 0) {
        ;
    }
    P4_BIT2_PSSL = 1;

    return status_write;
}

uint8_t r_pmic_prot_spi_read(uint16_t r_addr) {

    P4_BIT2_PSSL = 0;
    g_spi_csi10_tx_done = 0;

    status_write = 0x00;


    read_data_crc[3] = 0x00;
    crc_data = 0x00;

    write_data_crc[0] = 0x80 + (r_addr >> 8);
    write_data_crc[1] = (r_addr & 0xFF);
    write_data_crc[2] = 0x01;
    write_data_crc[3] = 0x00;

    write_data_crc[4] = 0x00;

    status_write = R_CSI10_Send_Receive(write_data_crc,sizeof(write_data_crc), read_data_crc);
    while (g_spi_csi10_tx_done == 0) {
            ;
    }
    read_value = read_data_crc[3];

    P4_BIT2_PSSL = 1;

    return read_value;
}`

Waveform output:
Multibyte Write Transaction
Read 0x125 and 0x126 reg address

I’m expecting to read 0xFA, 0xEF, 0xCD, and 0x9F in 0x125, 0x126, 0x127, and 0x128 respectively.