LAN91C111 Datasheet, PDF (55/142 Pages) SMSC Corporation – 10/100 Non-PCI Ethernet Single Chip MAC + PHY

10/100 Non-PCI Ethernet Single Chip MAC + PHY
Datasheet
BROADCAST - Receive frame was broadcast. When a broadcast packet is received, the MULTCAST
bit may be also set on the status word in addition to the BRODCAST bit. The software implement may
just ignore the MULTCAST bit if for BRODCAST packet.
BADCRC - Frame had CRC error, or RX_ER was asserted during reception.
ODDFRM - This bit when set indicates that the received frame had an odd number of bytes.
TOOLNG - Frame length was longer than 802.3 maximum size (1518 bytes on the cable).
TOOSHORT - Frame length was shorter than 802.3 minimum size (64 bytes on the cable).
HASH VALUE - Provides the hash value used to index the Multicast Registers. Can be used by
receive routines to speed up the group address search. The hash value consists of the six most
significant bits of the CRC calculated on the Destination Address, and maps into the 64 bit multicast
table. Bits 5,4,3 of the hash value select a byte of the multicast table, while bits 2,1,0 determine the
bit within the byte selected. Examples of the address mapping:
ADDRESS
ED 00 00 00 00 00
0D 00 00 00 00 00
01 00 00 00 00 00
2F 00 00 00 00 00
HASH VALUE 5-0
000 000
010 000
100 111
111 111
MULTICAST TABLE BIT
MT-0 bit 0
MT-2 bit 0
MT-4 bit 7
MT-7 bit 7
8.3
MULTCAST - Receive frame was multicast. If hash value corresponds to a multicast table bit that is
set, and the address was a multicast, the packet will pass address filtering regardless of other filtering
criteria.
I/O Space
The base I/O space is determined by the IOS0-IOS2 inputs and the EEPROM contents. To limit the
I/O space requirements to 16 locations, the registers are assigned to different banks. The last word of
the I/O area is shared by all banks and can be used to change the bank in use. Registers are
described using the following convention:
OFFSET
NAME
TYPE
SYMBOL
HIGH
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
BYTE
X
X
X
X
X
X
X
X
LOW
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
BYTE
X
X
X
X
X
X
X
X
FFSET - Defines the address offset within the IOBASE where the register can be accessed at,
provided the bank select has the appropriate value.
The offset specifies the address of the even byte (bits 0-7) or the address of the complete word.
The odd byte can be accessed using address (offset + 1).
Some registers (like the Interrupt Ack., or like Interrupt Mask) are functionally described as two eight
bit registers, in that case the offset of each one is independently specified.
SMSC LAN91C111-REV B
55
DATASHEET
Revision 1.8 (07-13-05)