1 Build a Frame

Create a valid frame based on address and data with parity.

Uint16 assembleSPICmd_682(Uint16 write, Uint16 address, Uint8 data)
{
    Uint16 assembledCmd = 0; // Build this to shift through parity calculation
    Uint16 parity = 0;       // Parity bit calculated here
    Uint16 packet = 0;       // This will be what we send

    if(write)
    {
        assembledCmd |= 0x8000;  // Set CMD = 1
    }

    assembledCmd |= (((address << 9) & 0x7E00) | (Uint16)(data & 0x00FF));
    packet = assembledCmd;

    // Calculate parity
    while(assembledCmd > 0)
    {
        // Count the number of 1s in the LSb
        if(assembledCmd & 0x0001)
        {
            parity++;
        }
        // Shift right
        assembledCmd >>= 1;
    }

    // If the LSb is a 0 (even # of 1s), we need to add the odd parity bit
    if(!(parity & 0x0001))
    {
        packet |= (1 << 8);
    }

    return(packet);
}