Datasheet

AN83
AN83REV2 55
ture storing the Driver Configuration Block in
BIOS space.
OBTAINING IEEE ADDRESSES
Each node of a Local Area Network has a unique
address for the media access control (MAC). This
makes it possible for that particular node to have
unique identity for data communication. This ad-
dress, known as the IEEE physical address, con-
sists of 48 bits of data. This address is assigned to
a LAN physical interface node by the manufacturer
of the network interface card.
To ensure uniqueness of the address, 24 bits of out
of the 48 bits of the physical address are assigned
to the manufacturer by the IEEE standards commit-
tee. This 24 bit address is known as Organization-
ally Unique Identifier (OUI). The remaining 24
bits of the address are assigned by the manufactur-
er. For further information and an application for
an OUI, please contact the IEEE at the following
address:
IEEE Registration Authority,
IEEE Standards Department,
445 Hoes Lane, PO Box 1331
Piscataway, NJ 08855-1331, USA
Telephone: [phone]
FAX: [phone]
Adapter boards shipped as part of Cirrus’
CS8900A Evaluation Kit are programmed with an
IEEE Physical Address obtained from an allotment
assigned to Cirrus Logic by the IEEE.
Byte Offset Description Function
00h Header 8 bytes = “$CS89XX$”
08h Individual Address IEEE individual address. Same format as word 1Ch in Table 8
0Ah Individual Address IEEE individual address. Same format as word 1Dh in Table 8
0Ch Individual Address IEEE individual address. Same format as word 1Eh in Table 8
0Eh ISA Configuration Flags Same format as word 1Fh in Table 8
10h Packet Page Base 12 MSBs of 24-bit address (lower 12 bits assumed = 0)
12h Boot PROM Base 12 MSBs of 24-bit address (lower 12 bits assumed = 0)
14h Boot PROM Mask 12 MSBs of 24-bit addr mask (lower 12 bits assumed = 0)
16h Transmission Control Same format as word 23h in Table 8
18h Adapter Configuration Same format as word 24h in Table 8
1Ah EEPROM Revision Same format as word 25h in Table 8
1Ch Reserved Reserved for future use, set to 0
1Eh Mfg Date Same format as word 27h in Table 8
20h-25h IEEE Individual Addr Copy of 6 bytes at offset 08h
26h Reserved Reserved for future use, set to 0
28h Reserved Reserved for future use, set to 0
2Ah Reserved Reserved for future use, set to 0
2Ch Reserved Reserved for future use, set to 0
2Eh Checksum Word-wide checksum of words 08h to 2Fh (zero sum)
30h EISA ID (high word) Same format as word 30h in Table 8
32h EISA ID (low word) Same format as word 31h in Table 8
34h Serial Number Same format as word 32h in Table 8
36h Serial Number Same format as word 33h in Table 8
38h LDSR Checksum Same format as word 34h in Table 8
Table 9. Format of Driver Configuration Block in BIOS space