SPRZ342O January 2011 – April 2021 TMS320F28062 , TMS320F28062-Q1 , TMS320F28062F , TMS320F28062F-Q1 , TMS320F28063 , TMS320F28064 , TMS320F28065 , TMS320F28066 , TMS320F28066-Q1 , TMS320F28067 , TMS320F28067-Q1 , TMS320F28068F , TMS320F28068M , TMS320F28069 , TMS320F28069-Q1 , TMS320F28069F , TMS320F28069F-Q1 , TMS320F28069M , TMS320F28069M-Q1
VCU: First CRC Calculation May Not be Correct
0, A, B
Due to the internal power-up state of the VCU module, it is possible that the first CRC result will be incorrect. This condition applies to the first result from each of the eight CRC instructions. This rare condition can only occur after a power-on reset, but will not necessarily occur on every power on. A warm reset will not cause this condition to reappear.
The application can reset the internal VCU CRC logic by performing a CRC calculation of a single byte in the initialization routine. This routine only needs to perform one CRC calculation and can use any of the CRC instructions. At the end of this routine, clear the VCU CRC result register to discard the result.
An example is shown below.
_VCUcrc_reset
MOVZ XAR7, #0
VCRC8L_1 *XAR7
VCRCCLR
LRETR