Dell Latitude E5440 User Manual

CAUTION: A CAUTION indicates either potential damage to hardware or loss of data and tells you how to avoid the
problem.

Description

Reference
Designator

Volatility Description

User
Accessible
for external
data

Remedial Action (Action
necessary to prevent loss of
data)

Embedded
Flash in
embedded
controller
MEC5075

U38

256K and 2K byte of
embedded Flash memory for
embedded controller BIOS
code, asset tag and BIOS
passwords

No

N/A
Panel

EEDID
EEPROM

Part of panel
assembly

Non Volatile memory 64K
bytes. Stores panel
manufacturing information,
display configuration data

No

N/A

System
BIOS

U1,U2

Non Volatile memory, 64Mbit
(8MB), 32Mbit (4MB) System
BIOS and Video BIOS for
basic boot operation, PSA (on
board diags), PXE diags.

No

N/A

System
Memory –
DDR3L
memory

Connectors
JDIMM1
and
JDIMM2

Volatile memory in OFF state
(see state definitions later in
text) One or both modules will
be populated. System memory
size will depend on SoDIMM
modules and will be between
1GB and 8GB

Yes

Power off system

System
memory
SPD
EEPROM

On memory
SoDIMM(s)
– one or two
present

Non-Volatile memory 2Kbit
(256 bytes). One device
present on each SoDIMM.
Stores memory manufacturer
data and timing information
for correct operation of system
memory.

No

N/A

RTC
CMOS –
BBRAM
(battery
backed up)

UC1

Non Volatile memory 256
bytes. Stores CMOS
information

No

Remove the on-board coin cell
battery

Video
memory –
frame
buffer

UMA
architecture­uses system
DDR3L.
Discrete
graphics

Volatile memory in off state.
2GB DDR3L for Discrete
Graphics systems. UMA uses
main system memory size
allocated out of main memory.

No

Enter S3-S5 state described
below.

Statement of Volatility – Dell Latitude™ E5440/E5540

The Dell Latitude™ E5440/E5540 contains both volatile and non-volatile (NV) components. Volatile components lose their
data immediately after power is removed from the component. Non-volatile (NV) components continue to retain their data
even after power is removed from the component. The following NV components are present on the Dell Latitude™
E5440/E5540 system board.

Table 1. List of Non-Volatile Components on System Board

Month yyyy

Description

Reference
Designator

Volatility Description

User
Accessible
for external
data

Remedial Action (Action
necessary to prevent loss of
data)

systems use
DDR3L
(UV4-UV7)
for frame
buffer

DP hub
FW

U7

This is volatile memory for DP
hub FW (1Mbit).

No

N/A

mSATA

JMINI2

mSATA module would share
with WWAN module on full
size mini-card. Non Volatile
memory (SSD)

Yes

Low level format
TPM
Controller

U25

Non Volatile memory, 2K bits
(256 bytes) ROM

No

N/A

Hard drive

User
replaceable

Non Volatile magnetic media,
various sizes in GB

yes

Low level format

CD­ROM/RW/
DVD/
DVD+RW/
Diskette
Drives

User
replaceable

Non Volatile optical media.

Yes

Low level format/erase

CAUTION: All other components on the system board lose data if power is removed from the system. Primary power
loss (unplugging the power cord and removing the battery) destroys all user data on the memory (DDR3L,
1333/1600MHz). Secondary power loss (removing the on-board coin-cell battery) destroys system data on the system
configuration and time-of-day information.

All other components on the motherboard will lose data once power is removed from the system. Primary power loss
(Unplug the power cord and remove the battery) will destroy all user data on the memory (DDR3L, 1333/1600MHz).
Secondary power loss (removing the on board coin-cell battery) will destroy system data on the system configuration
and time-of-day information.

In addition, to clarify memory volatility and data retention in situations where the system is put in different ACPI power
states the following is provided (those ACPI power states are S0, S1, S3, S4 and S5):

S0 state is the working state where the dynamic RAM is maintained and is read/write by the processor.
S1 state is a low wake-up latency sleeping state. In this state, no system context is lost (CPU or chip set) and hardware

maintains all system contexts.
S3 is called “suspend to RAM” state or stand-by mode. In this state the dynamic RAM is maintained. Dell systems will

be able to go to S3 if the OS and the peripherals used in the system supports S3 state. Linux, Win7 and Win8 support
S3 state.

S4 is called “suspend to disk” state or “hibernate” mode. There is no power. In this state, the dynamic RAM is not
maintained. If the system has been commanded to enter S4, the OS will write the system context to a non-volatile
storage file and leave appropriate context markers. When the system is coming back to the working state, a restore file
from the non-volatile storage can occur. The restore file has to be valid. Dell systems will be able to go to S4 if the OS
and the peripherals support S4 state. Win7 and Win8 support S4 state.

S5 is the “soft” off state. There is no power. The OS does not save any context to wake up the system. No data will

remain in any component on the system board, i.e. cache or memory. The system will require a complete boot when
awakened. Since S5 is the shut off state, coming out of S5 requires power on which clears all registers.

The following table shows all the states supported by Dell Latitude™E5440/E5540: Model Number

Model Number

S0

S1

S3

S4

S5

Dell Latitude™ E5440

X X X X

Dell Latitude™ E5540

X X X X