SPI polynomial register
| CRCPOLY | CRC polynomial register This register contains the polynomial for the CRC calculation. The default 9-bit polynomial setting 0x107 corresponds to default 8-bit setting of DSIZE. It is compatible with setting 0x07 used at some other ST products with fixed length of the polynomial string where the most significant bit of the string is always kept hidden. Length of the polynomial is given by the most significant bit of the value stored at this register. It has to be set greater than DSIZE. CRC33_17 bit has to be set additionally with CRCPOLY register when DSIZE is configured to maximum 32-bit or 16-bit size and CRC is enabled (to keep polynomial length grater than data size). Note: CRCPOLY[31:16] bits are reserved at instances with data size limited to 16-bit. There is no constrain when 32-bit access is applied at these addresses. Reserved bits 31-16 are always read zero while any write to them is ignored. |