2-18 Chapter 2: 7401-4xxx Product Overview
The Flash device is divided into four areas, as described below.
System Address FLASH Memory Area
F0000H FFFFFH 64 kB Main BIOS
EE000H EFFFFH 8 kB System BIOS Reserved during boot
ED000H EDFFFH 4 kB Plug and Play ESCD Storage Area
E0000H ECFFFH 52 kB System/VGA BIOS Reserved during boot
BIOS Upgrades
Flash memory makes distributing BIOS upgrades easy. A new version
of the BIOS can be installed from the hard disk, network or through a
serial port.
The disk-based Flash upgrade utilities , P h las h. ex e and WinPhlash.exe,
ensure the upgrade BIOS extension matches the target system to
prevent accidentally installing a BIOS for a differe n t typ e of syst em.
Setup Utility
The ROM-based Setup utility allows the sys tem configuration to be
modified without opening the system for most basic changes. The
Setup utility is accessible only during the Power-On Se lf Te s t (POST)
by pressing the <F2> key after the POST memory test has begun and
before boot begins. A prompt may be ena ble d tha t in fo rms u se rs t o
press the <F2> key to access Setup.
Note: An external alphanumeric keyboard is recommended for
running the BIOS CMOS Setup Utility. Otherwise, a Touch Screen can
be used.
Plug and Play
The Processor BIOS also has a setup option to support the Windows
runtime plug and play utilities. When this op tion is selected, only
devices critical to boot are assi gn e d r es ou rces by the BIOS. Device
Node information is available for all devices to en su re com patibilit y
with Windows 95. System configuration in form ation is stored in ESCD
format. The ESCD data will be cleared upon loss of the CMOS voltag e.