HP ProDesk 400 G4 Small Form Factor (SFF) - Maintenance and Service Guide

Nonvolatile memory
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)
2-megabytes No Yes Provides
protected
backup of critical
System BIOS
code, EC
rmware, and
critical PC
conguration
data for select
platforms that
support HP Sure
Start.
For more
information, see
Using HP Sure
Start (select
models only)
on page 119.
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
and time.
This memory is
not write-
protected.
Controller (NIC)
EEPROM
64-kilobytes
(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.
Nonvolatile memory 115