Maintenance and Service Guide

Nonvolatile memory usage
Nonvolatile
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?
HP Sure Start ash
(select models
only)
8 MBytes No Yes Provides
protected
backup of
critical System
BIOS code, EC
rmware,
and critical
computer
conguration
data for select
platforms that
support HP Sure
Start.
For more
information, see
Using HP Sure
Start (select
models only)
on page 70.
Data cannot be written to this
device via the host processor.
The content is managed solely
by the HP Sure Start
Embedded Controller.
This memory is protected
by the HP Sure Start
Embedded Controller.
Real Time Clock
(RTC) battery
backed-up CMOS
conguration
memory
256 Bytes No Yes Stores system
date and time
and noncritical
data.
RTC battery backed-up CMOS
is programmed using
the Computer Setup (BIOS), or
changing the Microsoft
Windows date & time.
This memory is not write-
protected.
Controller (NIC)
EEPROM
64 KBytes (not
customer
accessible)
No Yes Stores NIC
conguration
and NIC
rmware.
NIC EEPROM is programmed
using a utility from the NIC
vendor that can be run from
DOS.
A utility is required to
write data to this memory
and is available from
the NIC vendor. Writing
data to this ROM in an
inappropriate manner will
render the NIC non-
functional.
DIMM Serial
Presence Detect
(SPD) conguration
data
256 Bytes per
memory
module, 128
Bytes
programmable
(not customer
accessible)
No Yes Stores memory
module
information.
DIMM SPD is programmed by
the memory vendor.
Data cannot be written to
this memory when
the module is installed in a
computer. The specic
write-protection method
varies by memory vendor.
System BIOS 9 MBytes Yes Yes Stores system
BIOS code
and computer
conguration
data.
System BIOS code is
programmed at the factory.
Code is updated when
the system BIOS is updated.
Conguration data
and settings are input using
the Computer Setup (BIOS) or
a custom utility.
NOTE: Writing data to
this ROM in an
inappropriate manner can
render the computer non-
functional.
A utility is required for
writing data to this
memory and is available
on the HP website; go to
http://www.hp.com/
support. Select Find your
product, and then follow
Nonvolatile memory usage 67