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 PC
conguration
data for select
platforms that
support HP Sure
Start.
For more
information, see
Using HP Sure
Start (select
models only)
on page 153.
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
conguration
memory
256 Bytes No Yes Stores system
date and time
and noncritical
data.
RTC battery backed-up CMOS
is programmed using the
Tablet Setup (BIOS), or
changing the Microsoft
Windows date and time.
This memory is not write-
protected.
Controller (NIC)
EEPROM
64 KBytes (not
customer
accessible)
No Yes Stores NIC
conguration
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) conguration
data
256 Bytes per
memory board,
128 Bytes
programmable
(not customer
accessible)
No Yes Stores memory
board
information.
DIMM SPD is programmed by
the memory vendor.
Data cannot be written to
this memory when the
board is installed in a PC.
The specic write-
protection method varies
by memory vendor.
System BIOS 9 MBytes Yes Yes Stores system
BIOS code and
PC conguration
data.
System BIOS code is
programmed at the factory.
Code is updated when the
system BIOS is updated.
Conguration data and
settings are input using the
Tablet Setup (BIOS) or a
custom utility.
NOTE: Writing data to
this ROM in an
inappropriate manner can
render the PC 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, and select your
country. Select Drivers &
Downloads, and then
150 Chapter 11 Statement of memory volatility