Forum Post: RM48 CRC16 Help

Hi,

I am wishing to use the RM48's CRC module to generate a CRC16 (polynomial 0x1021).

I have software based libraries working well for years, however can not get the hardware CRC module to produce the same results.

Here is my input array and the function call:

Luint8 u8Buffer[] = {0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x01, 0x02}; u16HWCRC = u166RM4_CRC__Calculate_CRC16((const Luint16*)&u8Buffer[0], 8, 0x1021); 

Here is my hardware CRC code:

Luint16 u166RM4_CRC__Calculate_CRC16(const Luint16 * pu16Data, Luint32 u32CRCLengthBytes, Luint16 u16CRC_Seed) {     Luint32 u32Counter;     Luint32 u32LengthWords;     union     {      Luint16 u16[2];      Luint32 u32;     }unT;      //reset the module  crcREG->CTRL0 = 0x00000001U;  crcREG->CTRL0 = 0x00000000U;   //clear control reg2 and set into full CPU mode  crcREG->CTRL2 = 0x00000000U;  crcREG->CTRL2 |= CRC_FULL_CPU;   //place the seed in the PSA register Low  unT.u16[1] = 0;  unT.u16[0] = u16CRC_Seed;  crcREG->PSA_SIGREGL1 = unT.u32;    //write the groups of U16's to the register  u32LengthWords = u32CRCLengthBytes >> 1;      for(u32Counter = 0; u32Counter < u32LengthWords; u32Counter++)     {      //update only the lower word of the REGL      unT.u16[1] = 0;      unT.u16[0] = pu16Data[u32Counter];      crcREG->PSA_SIGREGL1 = unT.u32;     }      //return with the CRC     unT.u32 = crcREG->PSA_SIGREGL1;     return (Luint16)unT.u16[0]; } 

The result from the CRC across the data array should be 0x6DD2, however I get 0xFEF8.  Can anyone please help to show what I am doing wrong?

Note:  I am using Full CPU mode for the time being.

Thanks

Stomp.