This Hash Table receive filter on the ENC28J60, ENCX24J600, and PIC18F97J60 microcontroller family performs a CRC calculation over the six destination address bytes in a received packet, then uses that value as a pointer into the EHT0-EHT7 registers. If the bit that the pointer points to is set, the packet will be received. The Microchip Hash Table Filter Entry Calculator will determine the bit that must be set in this register bank for a given destination address. If you have a fixed MAC address, known at design time, you can set up your Hash Table receive filter in your code using the value obtained from this tool; otherwise, you must use the SetRXHashTableEntry() function to set it during runtime. To use this tool, specify the address of your device, click calculate, and the CRC value and the corresponding bit will be displayed in the output box.
