Nonvolatile Memory Usage - HP EliteDesk 705 G4 Maintenance And Service Manual

Nonvolatile memory usage

Nonvolatile
Memory Type Amount (Size)
HP Sure Start flash 8 MBytes
(select models
only)
Real Time Clock 256 Bytes
(RTC) battery
backed-up CMOS
configuration
memory
Controller (NIC) 64 KBytes (not
EEPROM customer
accessible)
DIMM Serial 256 Bytes per
Presence Detect memory
(SPD) module, 128
configuration data Bytes
programmable
(not customer
accessible)
System BIOS 9 MBytes
136 Appendix D Statement of memory volatility
Does this Does this
memory memory
store retain data
customer when power
data? is removed?
No Yes
No Yes
No Yes
No Yes
Yes Yes
What is the
purpose of this How is data input into this
memory? memory?
Provides Data cannot be written to this
protected device via the host processor.
backup of The content is managed
critical System solely by the HP Sure Start
BIOS code, EC Embedded Controller.
firmware, and
critical
computer
configuration
data for select
platforms that
support HP
Sure Start.
For more
information,
see Using HP
Sure Start
(select models
only)
on page 139.
Stores system RTC battery backed-up CMOS
date and time is programmed using the
and noncritical Computer Setup (BIOS), or
data. changing the Microsoft ®
Windows date & time.
Stores NIC NIC EEPROM is programmed
configuration using a utility from the NIC
and NIC vendor that can be run from
firmware. DOS.
Stores memory DIMM SPD is programmed by
module the memory vendor.
information.
Stores system System BIOS code is
BIOS code and programmed at the factory.
computer Code is updated when the
configuration system BIOS is updated.
data. Configuration data and
settings are input using the
Computer Setup (BIOS) or a
custom utility.
How is this memory
write-protected?
This memory is protected
by the HP Sure Start
Embedded Controller.
This memory is not write-
protected.
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.
Data cannot be written to
this memory when the
module is installed in a
computer. The specific
write-protection method
varies by memory vendor.
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