HP EliteBook 820 G1 Maintenance And Service Manual page 178

Non Volatile
Memory
Type
Keyboard ROM
DIMM Serial
Presence Detect
(SPD)
configuration
data
System BIOS
168 Chapter 10 Statement of Volatility
Amount Does this
(Size) memory
store
customer
data?
64 KBytes (not No
customer
accessible)
256 Bytes per No
memory
module, 128
Bytes
programmable
(not customer
accessible)
4 to 5 MBytes Yes
Does this What is the
memory purpose of
retain data this
when power memory?
is removed?
Yes Stores firmware
code
(keyboard,
mouse, &
battery
management).
Yes Stores memory
module
information.
Yes Store system
BIOS code and
PC
configuration
data.
How is data How is this
input into memory
this write
memory? protected?
Programmed at A utility is
the factory. required for
Code is writing data to
updated when this memory
the system BIOS and is available
is updated. on the HP
website.
Writing data to
this ROM in an
inappropriate
manner can
render the PC
nonfunctional.
Programmed by Data cannot be
the memory written to this
vendor. memory when
the module is
installed in a
PC. The specific
write protection
method varies
by memory
vendor.
System BIOS A utility is
code is required for
programmed at writing data to
the factory. this memory
Code is and is available
updated when on the HP
the system BIOS website.
is updated. Writing data to
Configuration this ROM in an
data and inappropriate
settings are manner can
input using the render the PC
F10 setup utility nonfunctional.
or a custom
utility.
ENWW