Cypress S6J3200 Series, Manual

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CHAPTER 21:Ethernet MAC
598 S6J3200 Series Hardware Manual Document Number: 002-04852 Rev. *G
The reset state of the Type ID Match registers is “0”, hence each is initially disabled.
The following example illustrates the use of the address and Type ID Match registers for a MAC address
of 21:43:65:87:A9:CB:
Preamble 55
h
SFD D5
h
DA (Octet 0 – LSB) 21
h
DA (Octet 1) 43
h
DA (Octet 2) 65
h
DA (Octet 3) 87
h
DA (Octet 4) A9
h
DA (Octet 5 - MSB) CB
h
SA (Octet 0 - LSB) 1.)
SA (Octet 1) 1.)
SA (Octet 2) 1.)
SA (Octet 3) 1.)
SA (Octet 4) 1.)
SA (Octet 5 - MSB) 1.)
Type ID (MSB) 43
h
Type ID (LSB) 21
h
1. Contains the address of the transmitting device.
The sequence above 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 match registers
must be set up:
Specific Address 1 Bottom (0x088) 87654321
h
Specific Address
1 Top (0x08C) 0000CBA9h
And for a successful match to the Type ID, the Type ID Match 1 register must be set up:
Type ID Match 1 (0x0A8) 80004321
h
3.5.1.
Broadcast Address
Frames with the broadcast address of FFFFFFFFFFFF
h
are stored to memory only if the no_broadcast bit
in the Network Configuration register is set to “0”.
3.5.2.
Hash Addressing
The 64-bit Hash register (Hash Top/Hash Bottom) takes up two locations in the memory map. The least
significant bits are stored in Hash Bottom register and the most significant bits in Hash Top register.
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]