Rabbit Rabbit 4000, User Manual

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208 Rabbit 4000 Microprocessor User’s Manual
20.3.5 Multicast Addressing
A physical address match requires that the received frame address is a physical address
that matches every bit of the programmed receive address. A broadcast address match
requires that all 48 bits of the received frame address be “ones.” A multicast address
match requires the received frame address to be a multicast address (LSB of the address is
one) and a match in the multicast address filter. The multicast address filter uses the six
most significant bits of the CRC calculated on the receive address as an index into a 64-
by-1 bit table written under program control. A one in the corresponding table entry con-
stitutes a multicast address match as far as the network port is concerned. A table of one
set of unique multicast addresses corresponding to each filter bit is shown below. The
table shows the least significant byte of the multicast address; the remaining five bytes of
the address are all zeros for this set of multicast addresses.
Register Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
NAMF7R 0x17 0x0B 0x05 0x19 0x85 0x99 0x97 0x8B
NAMF6R 0xD9 0xC5 0xCB 0xD7 0x4B 0x57 0x59 0x45
NAMF5R 0xCF 0xD3 0xDD 0xC1 0x5D 0x41 0x4F 0x53
NAMF4R 0x01 0x1D 0x13 0x0F 0x93 0x8F 0x81 0x9D
NAMF3R 0x5F 0x43 0x4D 0x51 0xCD 0xD1 0xDF 0xC3
NAMF2R 0x91 0x8D 0x83 0x9F 0x03 0x1F 0x11 0x0D
NAMF1R 0x87 0x9B 0x95 0x89 0x15 0x09 0x07 0x1B
NAMF0R 0x49 0x55 0x5B 0x47 0xDB 0xC7 0xC9 0xD5