Maintenance and Service Guide

B Statement of memory volatility
The purpose of this chapter is to provide information regarding erasing and resetting non-volatile memory
integrated into the system board. This chapter outlines instructions for restoring memory that can contain
personal data or custom settings.
HP Business PC products that use Intel- or AMD-based system boards contain volatile DDR memory. The amount
of non-volatile memory present in the system depends upon the system conguration. Intel- and AMD-based
system boards contain non-volatile memory subcomponents as originally shipped from HP, assuming that no
subsequent modications have been made to the system and assuming that no applications, features, or
functionality have been added to or installed on the system.
Nonvolatile memory usage
The following table lists the non-volatile memory regions that are integrated into the HP Z8 G4 Workstation
system board:
Non-volatile
memory type Amount (Size)
Does this
memory store
customer
data?
Does this
memory retain
data when
power is
removed?
What is the
purpose of this
memory?
How is data
input into this
memory?
How is this
memory
write-
protected?
How is this
memory reset
or cleared?
Real time clock
(RTC) battery
backed up
CMOS
conguration
memory
(CMOS)
256 Bytes Yes Yes Stores system
date and time,
LAN settings,
and limited
security
settings.
Using the F10
Setup utility or
changing the
Microsoft
Windows date
and time.
This memory
is not write-
protected. HP
recommends
password
protecting the
F10 Setup
utility.
The CMOS
conguration
memory is
cleared by
removing the
3V battery
from the
system board
for at least 5
minutes.
Network
Interface
Controller
(NIC) EEPROM
64 Kbytes (per
NIC; not
customer
accessible)
No Yes Store NIC
conguration,
MAC address
and NIC
rmware.
Using a factory
utility from the
NIC vendor
that can be
run from DOS
or the EFI
shell.
There are no
readily-
available user
tools to write
to this
memory
region. A
checksum is
used to
disallow any
bit
modications
There are no
HP tools to
write or
modify this
memory in any
way. NIC
vendors may
have tools to
change
settings in this
memory
region.
Battery-
Backed SIO
RAM
64 bytes Yes Yes Stores basic
power
management
rmware
settings and
power loss
error
reporting.
Programmed
at the factory.
Code is
updated when
the system
BIOS is
updated.
A utility is
required for
writing data to
this memory
and is
available on
the
HP website.
Writing data to
The SIO RAM
memory is
cleared by
removing the
3V battery
from the
system board
for at least 5
minutes.
96 Appendix B Statement of memory volatility