Datasheet

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 (
GMAC_SAB1) (Address 0x088) 0x87654321
Specific Address 1 Top register (GMAC_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 (GMAC_TIDM1) (Address 0x0A8) 0x80004321
38.6.8 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.
38.6.9 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.
If the hash index points to a bit that is set in the Hash register then the frame will be matched according to whether
the frame is multicast or unicast.
A multicast match will be signaled if the multicast hash enable bit is set, da[0] is logic 1 and the hash index points to a
bit set in the Hash register.
A unicast match will be signaled if the unicast hash enable bit is set, da[0] is logic 0 and the hash index points to a bit
set in the Hash register.
To receive all multicast frames, the Hash register should be set with all ones and the multicast hash enable bit should
be set in the Network Configuration register.
38.6.10 Copy all Frames (Promiscuous Mode)
If the Copy All Frames bit is set in the Network Configuration register then all frames (except those that are too long,
too short, have FCS errors or have GRXER asserted during reception) will be copied to memory. Frames with FCS
errors will be copied if bit 26 is set in the Network Configuration register.
SAM E70/S70/V70/V71 Family
GMAC - Ethernet MAC
© 2019 Microchip T
echnology Inc.
Datasheet
DS60001527D-page 590