82595TX Datasheet, PDF (21/59 Pages) Intel Corporation – ISA/PCMCIA HIGH INTEGRATION ETHERNET CONTROLLER

82595TX
4 5 Serial EEPROM Interface
A Serial EEPROM a Hyundai HY93C46 or equiva-
lent IC stores configuration data for the 82595TX
The use of an EEPROM enables 82595TX designs
to be implemented without jumpers (the use of jump-
ers to select IO windows is optional ) The 85295TX
provides two complete interfaces to a serial
EEPROM (Port1 or Port2 and only one port can be
used) Port1 is used to store configuration informa-
tion in the EEPROM such as IO Base Address and
Interrupt selection and is backwards pin compatible
to the 82595 EEPROM interface Port2 stores con-
figuration information as in Port1 in addition it is
used to store Plug N’ Play information as defined in
the Plug N’ Play specification Plug N’ Play allows
peripheral functions to be added to a PC (such as
adapter cards) without the need to individually con-
figure each parameter (e g Interrupt IO Ad-
dress etc) Information describing system resources
are contained within the 82595TX configuration reg-
isters This allows Auto-configuration software
which is usually contained in the BIOS or O S to
identify system resource usage identify conflicts
and automatically re-configure the 82595TX
The 82595TX automatically accesses Register 0 of
the EEPROM upon a RESET in ISA Bus Interface
mode Register 0 contains the information that the
82595TX must be configured to allow CPU
accesses to it (IO Mapping Window FLASH Detect
Enable Auto I O Enable Boot EPROM FLASH
Window Host Bus Width and Plug N’ Play Enable)
following a system boot The format for EEPROM
Register 0 is shown in Figure 4-1 Note that all 0’s
are assumed to be reserved In the case where an
EEPROM is either unprogrammed (each bit defaults
to a 1) or completely erased (all 0’s) the 82595TX
will default to IO Address 300h
For additional information regarding a Plug N’ Play implementation for the 82595TX please consult the
82595TX User Manual and LAN595TX Specification available through your local sales representative
The latest Plug N’ Play Specification is available by Microsoft
D15 D14 D13 D12 D11 D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
MSb
IO Mapping Window
Flash
Auto
BT FLSH Window
Hst
PnP
0
0
0
LSb
Det
I O En MSb
LSb Wdt
En
Figure 4-1 EEPROM Register 0
21