Datasheet

DA (Octet 4) A9
DA (Octet 5 - MSB) CB
SA (LSB) 00 (see Note)
SA 00(see Note)
SA 00(see Note)
SA 00(see Note)
SA 00(see Note)
SA (MSB) 00(see Note)
Type ID (MSB) 43
Type ID (LSB) 21
Note: Contains the address of the transmitting device.
The previous sequence shows the beginning of an Ethernet frame. Byte order of transmission is from top
to bottom, as shown. For a successful match to specific address 1, the following address matching
registers must be set up:
Specific Address 1 Bottom register (SAB1) (Address 0x088) 0x87654321
Specific Address 1 Top register (SAT1) (Address 0x08C) 0x0000CBA9
For a successful match to the type ID, the following Type ID Match 1 register must be set up:
Type ID Match 1 register (TIDM1) (Address 0x0A8) 0x80004321
24.6.8 Broadcast Address
Frames with the broadcast address of 0xFFFFFFFFFFFF are stored to memory only if the 'no broadcast'
bit in the Network Configuration register is set to zero.
24.6.9 Hash Addressing
The hash address register is 64 bits long and takes up two locations in the memory map. The least
significant bits are stored in Hash Register Bottom and the most significant bits in Hash Register Top.
The unicast hash enable and the multicast hash enable bits in the Network Configuration register enable
the reception of hash matched frames. The destination address is reduced to a 6-bit index into the 64-bit
Hash register using the following hash function: The hash function is an XOR of every sixth bit of the
destination address.
hash_index[05] = da[05] ^ da[11] ^ da[17] ^ da[23] ^ da[29] ^ da[35] ^ da[41] ^ da[47]
hash_index[04] = da[04] ^ da[10] ^ da[16] ^ da[22] ^ da[28] ^ da[34] ^ da[40] ^ da[46]
hash_index[03] = da[03] ^ da[09] ^ da[15] ^ da[21] ^ da[27] ^ da[33] ^ da[39] ^ da[45]
hash_index[02] = da[02] ^ da[08] ^ da[14] ^ da[20] ^ da[26] ^ da[32] ^ da[38] ^ da[44]
hash_index[01] = da[01] ^ da[07] ^ da[13] ^ da[19] ^ da[25] ^ da[31] ^ da[37] ^ da[43]
hash_index[00] = da[00] ^ da[06] ^ da[12] ^ da[18] ^ da[24] ^ da[30] ^ da[36] ^ da[42]
da[0] represents the least significant bit of the first byte received, that is, the multicast/unicast indicator,
and da[47] represents the most significant bit of the last byte received.
SAM D5x/E5x Family Data Sheet
GMAC - Ethernet MAC
© 2019 Microchip Technology Inc.
Datasheet
DS60001507E-page 495