Obtaining ieee addresses, An83 – Cirrus Logic AN83 User Manual

Page 55

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AN83

AN83REV3

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: (732) 562-3813
FAX: (732) 562-1571
Email: [email protected]
http://standards.ieee.org/regauth/oui/index.shtml

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

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