CRC constructor
CRC(])
Create a CRC with arguments.
Implementation
factory CRC(String name, int width, int poly, int init, bool refIn,
bool refOut, int xorOut,
[bool mapping = false]) {
final crc = mapping
? MappingCRC(name, width, poly, init, refIn, refOut, xorOut)
: SimpleCRC(name, width, poly, init, refIn, refOut, xorOut);
return crc;
}