New Features of DDR3 SDRAM

USER'S MANUAL
New Features of DDR3 SDRAM
Document No. E1503E10 (Ver.1.0)
Date Published March 2009 (K) Japan
URL: http://www.elpida.com
© Elpida Memory, Inc. 2009
User's Manual E1503E10 (Ver.1.0)
2
Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
INTRODUCTION
Readers
This manual is intended for users who design application systems using double data rate 3 synchronous DRAM (DDR3
SDRAM). Readers of this manual are required to have general knowledge in the fields of electrical engineering, logic circuits, as
well as detailed knowledge of the functions and usage of conventional synchronous DRAM (SDRAM), double data rate
synchronous DRAM (DDR SDRAM), and double data rate 2 synchronous DRAM (DDR2 SDRAM).
Explanatory Notes
Caution:
Information requiring particular attention
Note:
Footnote for items marked with Note in the text
Remarks: Supplementary information
Related Documents
Related documents indicated in this manual may include preliminary versions, but they may not be explicitly marked as
preliminary.
Document Name
Document No.
HOW TO USE SDRAM USER'S MANUAL
E0123N
HOW TO USE DDR SDRAM USER'S MANUAL
E0234E
HOW TO USE DDR2 SDRAM USER'S MANUAL
E0437E
Notice
This document is intended to give users understanding of basic functions and usage of DDR3 SDRAM. Descriptions in
this document are provided only for illustrative purpose in semiconductor product operation and application examples.
And numerical values are not guaranteed values. For details about the functions of individual products,
refer to the corresponding data sheet. The incorporation of these information in the design of the
customer's equipment shall be
done under the full responsibility of the customer. Elpida Memory, Inc. assumes no responsibility for any
losses
incurred by customers or third parties arising from the use of these information.
User's Manual E1503E10 (Ver.1.0)
3
Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
CONTENTS
CHAPTER 1
FEATURES OF DDR3 SDRAM (COMPARISON OF MAIN SPECIFICATIONS OF
DDR, DDR2 AND DDR3)........................................................................................................................5
1.1 Main Features ...........................................................................................................................................................6
1.1.1 Clock Frequency, Data Rate, Power Voltage and Interface..........................................................................................6
1.1.2 Number of Banks ...................................................................................................................................................6
1.1.3 Prefetch, Burst Length and tCCD .............................................................................................................................6
1.1.4 Posted CAS and Additive Latency (AL)....................................................................................................................8
1.1.5 Read Latency (RL) and Write Latency (WL) .............................................................................................................8
1.1.6 DQS (Data Strobe) .................................................................................................................................................9
1.1.7 VREF Pin ..............................................................................................................................................................9
1.1.8 /RESET Pin ...........................................................................................................................................................9
1.1.9 Output Driver Impedance (Ron), ODT and Calibrations ...........................................................................................10
1.1.10 ZQ Calibration ...................................................................................................................................................11
1.1.11 CLK-DQS Timing De-skew Mechanism...............................................................................................................12
1.1.12 Write Leveling ...................................................................................................................................................13
1.1.13 Multi Purpose Register (MPR).......................................................................................................................15
User's Manual E1503E10 (Ver.1.0)
4
Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
CHAPTER 1
FEATURES OF DDR3 SDRAM (COMPARISON OF MAIN SPECIFICATIONS OF DDR, DDR2, AND DDR3)
CHAPTER 1
FEATURES OF DDR3 SDRAM (COMPARISON OF MAIN
SPECIFICATIONS OF DDR, DDR2 AND DDR3)
DDR3 SDRAM has employed several new technologies for high-speed operation while inheriting the DDR2 SDRAM
architecture.
Table 1-1 Comparison of Main Specifications of DDR, DDR2 and DDR3
Item
Data rate/pin
CLK frequency
Power supply
(VDD/VDDQ)
Interface
Number of banks
Prefetch
Burst length
Posted CAS,
Additive latency
RL, WL
ZQ pin
/Reset pin
DQ driver impedance (Ron)
DQ driver calibration
ODT function
ODT calibration
Dynamic ODT
CLK-DQS de-skew
mechanism
Package
DDR
200/266/333/400 Mbps
(100/133/166/200 MHz)
2.5 ± 0.2 V
DDR2
400/533/667/800 Mbps
(200/266/333/400 MHz)
1.8 ± 0.1 V
DDR3
800/1066/1333/1600 Mbps
(400/533/667/800 MHz)
1.5 ± 0.075 V
SSTL_2
4
2 bits
2/4/8
No
SSTL_18
4 or 8
4 bits
4/8
Yes (AL = 0/1/2/3/4/5)
SSTL_15
8
8 bits
4 (burst chop)/8
Yes (AL = 0/CL - 1/CL - 2)
RL = CL (no AL)
WL = 1
N/A
N/A
Programmable
N/A
N/A
N/A
N/A
N/A
RL = AL + CL
WL = RL - 1 = AL + CL - 1
N/A
N/A
Programmable
For OCD calib.*2
Available
N/A
N/A
N/A
TSOP II
FBGA
RL = AL + CL
WL = AL + CWL
Available. For ZQ calib.*1
Available*3
Programmable
For ZQ calib.*1
Available
For ZQ calib.*1
Available*4
Available (Write leveling,
Read leveling)*5
FBGA
Notes: 1. ZQ Calibration: Calibrates DRAM ODT and Ron fluctuations with PVT (process, voltage, and temperature). External
resistor (240Ω±1%) is inserted between DRAM ZQ pin and GND for reference. To perform ZQ calibration, ZQCL or
ZQCS command is used. (This is a self-calibration in which DDR3 performs all the measurement and adjustment
automatically.)
2. OCD (Off Chip Driver Calibration): Calibrates DRAM Ron fluctuation with PVT. The external device connected to
DRAM performs impedance measurement and adjustment (not self-calibration). OCD is an optional feature in DDR2.
3. /RESET pin is introduced in DDR3 for system stability. /RESET is an active-low signal.
4. Dynamic ODT: ODT value during WRITE can be changed dynamically by enabling the dynamic ODT mode in
advance by MRS command. As a result, signal quality is improved.
5. DDR3 DIMM uses fly-by topology for CMD/ADD/CLK signals to improve signal quality. This causes flight time
difference between DQ/DM/DQS and CMD/ADD/CLK. DDR3 has de-skew mechanism to compensate flight time
difference.
User's Manual E1503E10 (Ver.1.0)
5
Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
CHAPTER 1
FEATURES OF DDR3 SDRAM (COMPARISON OF MAIN SPECIFICATIONS OF DDR, DDR2, AND DDR3)
1.1 Main Features
1.1.1 Clock Frequency, Data Rate, Power Voltage and Interface
DDR3 SDRAM achieves high-speed operation about twice of that of DDR2 SDRAM, but suppresses the increase in power
consumption by using a voltage of 1.5 V for the power supply and interface.
1.1.2 Number of Banks
DDR3 SDRAM has eight banks, which allows more efficient bank interleave access than that in the case of four banks.
1.1.3 Prefetch, Burst Length and tCCD
DDR3 SDRAM employs the 8-bit prefetch architecture for high-speed operation though DDR2 SDRAM employs 4-bit prefetch
architecture. The bus width of the DRAM core has been made eight times wider than the I/O bus width, which enables the
operating frequency of the DRAM core to be 1/8 of the data rate of the I/O interface section.
READ operation: Converts 8-bit data read in parallel from the DRAM core to serial data, and outputs it from the I/O pin in
synchronization with the clock (at double data rate).
WRITE operation: Converts serial data that is input from the I/O pin in synchronization with the clock (at double data rate) to
parallel data, and writes it to the DRAM core as 8-bit data.
User's Manual E1503E10 (Ver.1.0)
6
Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
CHAPTER 1
FEATURES OF DDR3 SDRAM (COMPARISON OF MAIN SPECIFICATIONS OF DDR, DDR2, AND DDR3)
Since 8 bits at a time are read from DDR3 memory
into the I/O buffer, so even if the data bus is handling
transfer at a rate of 1066 Mbps, the internal bus
operating at 133 MHz will be capable of handling this
if there is little other load, so high-speed operation
is realized.
Operating frequency
of internal bus
133 MHz
DDR3
SDRAM
Memory
core
External clock
frequency
533 MHz
Data bus
transfer rate
1066 Mbps
With the external clock 4 times of
internal clock, transfer 8 bits every
half-clock cycle.
I/O buffer
Prefetch = 8 bits
Transfer 8 bits per clock cycle.
DDR2
SDRAM
133 MHz
266 MHz
Memory
core
I/O buffer
133 MHz
DDR
SDRAM
Memory
core
133 MHz
SDR
SDRAM
Memory
core
533 Mbps
Prefetch = 4 bits
133 MHz
266 Mbps
I/O buffer
Prefetch = 2 bits
133 MHz
133 Mbps
I/O buffer
Prefetch = 1 bit
Figure 1-1 Comparison of DDR3 SDRAM, DDR2 SDRAM, DDR SDRAM, and SDR SDRAM Operations
User's Manual E1503E10 (Ver.1.0)
7
Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
CHAPTER 1
FEATURES OF DDR3 SDRAM (COMPARISON OF MAIN SPECIFICATIONS OF DDR, DDR2, AND DDR3)
Because of these features, the burst length is basically eight bits, but 4-bit burst length is also supported considering the
inheritance from DDR2 SDRAM. In that case, however, data is treated as if the second-half four bits are masked in an 8-bit
burst length access. (This is called the burst chop 4 mode (BC4).)
The column command interval (tCCD) also becomes 4tCK in connection with the 8-bit prefetch.
BA2 BA1 BA0 A12
0
0
0
A11
PPD
A10
A9
WR
A8
A7
DLL
TM
A6
A5
A4
/CAS latency
A3
A2
RST
CL
A1
A1
DQ
T5
T6
T7
T8
T9
T10
T11
0
0
1
1
T12
Dout Dout Dout Dout
n
n+1 n+2 n+3
Dout Dout Dout Dout
b
b+1 b+2 b+3
Burst length
A0
0
1
0
1
BL
8 (fixed)
4 or 8 (on the fly)
4 (fixed)
/CAS latency
Function: A12/BC
BL
A12/BC
Low
4 (on the fly)
Dout Dout Dout Dout Dout Dout Dout Dout Dout Dout Dout Dout Dout Dout Dout Dout
n
n+1 n+2 n+3 n+4 n+5 n+6 n+7
b
b+1 b+2 b+3 b+4 b+5 b+6 b+7
8 (on the fly)
READ (BL8) to READ (BL8)
DQ
Address field
Mode register 0
BL
The burst length (BL) of DDR3 SDRAM is usually 8 because prefetch data length is 8 bits. When address
[A1,A0] in the mode register 0 (MR0) is set to [1,0], BL is fixed to 4. When the Read command or
Write command is executed in the on-the-fly state ([A1,A0] = [0,1]), BL is 4 while A12 is low or 8 while A12 is
high. When BL is 4, start points of tWR and tWTR are the same as those when BL is 8.
T4
A0
High
Burst chopped
No burst chop
Continuous output is possible when BL = 8
Two-cycle idle state is generated when BL = 4.
Burst-chop
READ (BL4) to READ (BL4)
Figure 1-2 Illustration of Burst-Chop
1.1.4 Posted CAS and Additive Latency (AL)
DDR3 SDRAM also supports the posted CAS function and additive latency function.
For details of these functions, see our User's Manual HOW TO USE DDR2 SDRAM.
1.1.5 Read Latency (RL) and Write Latency (WL)
The time period from the issue of READ command to the output of the first data is called read latency (RL), and the time period
from the issue of WRITE command to the input of the first data is called write latency (WL), which are shown by clock count.
Definition of RL and WL is partly different between DDR2 SDRAM and DDR3 SDRAM.
Table 1-2 Differences in RL and WL between DDR2 SDRAM and DDR3 SDRAM
DDR2 SDRAM
DDR3 SDRAM
RL (Read latency)
RL = AL + CL
RL = AL + CL
WL (Write latency)
WL = RL - 1 = AL + CL - 1
WL = AL + CWL
CL
(2), 3, 4, 5, 6
5, 6, 7, 8, 9, 10, (11)
AL
0, 1, 2, 3, 4, (5)
0, CL - 1, CL - 2
N/A
5, 6, 7, 8
CWL
[Legend]
AL:
Additive latency
CL:
CAS latency
CWL: CAS write latency
User's Manual E1503E10 (Ver.1.0)
8
Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
CHAPTER 1
FEATURES OF DDR3 SDRAM (COMPARISON OF MAIN SPECIFICATIONS OF DDR, DDR2, AND DDR3)
1.1.6 DQS (Data Strobe)
Only differential DQS is available in DDR3 SDRAM because finer timing control is required due to high data rate.
1.1.7 VREF Pin
DDR3 SDRAM separates the VREF signals for data and for command/address.
1.1.8 /RESET Pin
DDR3 SDRAM has employed the /RESET pin newly. The /RESET pin is driven low during power-on or initialization process
or when a reset is required.
User's Manual E1503E10 (Ver.1.0)
9
Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
CHAPTER 1
FEATURES OF DDR3 SDRAM (COMPARISON OF MAIN SPECIFICATIONS OF DDR, DDR2, AND DDR3)
1.1.9 Output Driver Impedance (Ron), ODT and Calibrations
Output Driver Impedance (Ron):
− The output driver impedance (Ron) of DQ, DQS, /DQS, and DM is selectable in the same way as DDR2 SDRAM ([A5,A1] in
MR1).
− Ron may fluctuate with the process, voltage, and temperature (PVT).
DDR2 SDRAM can calibrate Ron fluctuation due to PVT using the optional OCD (off-chip driver calibration) function, but
DDR3 SDRAM uses the ZQ calibration function instead of the OCD function.
ODT (On Die Termination):
A termination resistor is provided in the chip to suppress signal reflection. This allows reduction in the number of external
resistors and impovement in signal quality.
− ODT resistance Rtt is selectable in the same way as DDR2 SDRAM ([A9,A6,A2] in MR1, [A10,A9] in MR2)
− DDR3 SDRAM inherits the ODT function provided for DDR2 SDRAM, and provides extended ODT mode.
Synchronous ODT:
ODT timing same as that of DDR2 SDRAM
Asynchoronous ODT: ODT timing in the slow exit power-down mode
Dynamic ODT:
Function that can dynamically switch the ODT resistance during WRITE operation without MRS
command, which impoves signal quality during WRITE operation.
DDR2 SDRAM
DDR3 SDRAM
On Die Termination (ODT Pin: H/L)
On Die Termination (ODT Pin: H/L)
Dynamic On Die Termination (Write & ODT Pin: H/L)
Terminator
OFF
ODT pin
→ Low
Active
ON
ODT pin
→ High
Standby
VTT
Terminator
ODT pin
→ Low
OFF
Active
ON
ODT pin
→ High
Standby
VTT
DRAM
Controller
DQ Bus
Controller
Reflection
Termination resistance is switchable
by MRS command
DQ Bus
Reflection
Termination resistance is switchable by MRS command and
WRITE command (dynamic ODT function).
Figure 1-3 Comparison between ODT of DDR2 SDRAM and Dynamic ODT of DDR3 SDRAM
To achieve high-speed data transfer, a termination resistor is provided in DDR2 SDRAM and DDR3 SDRAM to suppress signal
reflection on the bus.
Reflection of signals from each DRAM can be suppressed by controlling ON/OFF of the ODT pin (input: high/low).
DDR3 SDRAM can dynamically switch the termination resistance to improve signal quality during WRITE operation, enabling
stable operation at a transfer rate of gigahertz level.
(The ODT termination resistance (RTT_Nom) and the termination resistance (RTT_WR) used for the dynamic ODT function
can be set by the MRS. If the ODT pin is held high during WRITE operation with the dynamic ODT set to OFF, the value set by
RTT_Nom is used for the termination resistance.)
User's Manual E1503E10 (Ver.1.0)
10
Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
CHAPTER 1
FEATURES OF DDR3 SDRAM (COMPARISON OF MAIN SPECIFICATIONS OF DDR, DDR2, AND DDR3)
1.1.10 ZQ Calibration
Although ODT resistance Rtt fluctuates with PVT in some cases, DDR3 SDRAM can calibrate the Rtt fluctuation due to PVT,
which was not possible in DDR2 SDRAM. The ZQ calibration function is also used for Rtt calibration, as well as for Ron
calibration.
CK
Command
A10
Address
ZQCL
NOP/DESL
Valid
ZQCS
NOP/DESL
Valid
AL10 = H
A10 = H
X
X
CKE
tZQCS
tZQ init or tZQ oper
DQ bus*
Active
Hi-Z
Hi-Z
Active
Note: ODT must be disabled via ODT signal or MRS during calibration procedure.
* All devices connected to DQ bus should be high impedance during calibration.
Figure 1-4 ZQ Calibration
The ZQ calibration function is essential for normal operation of DDR3. With the reference of the external resistance (240Ω
±1%) connected to the ZQ pin, DDR3 calibrates the Ron and Rtt values of the ZQ pin agaist temperature and voltage
fluctuations (see figure 1-5).
RZQ
ZQ
240Ω±1%
Figure 1-5 External Resistance (RZQ)
ZQ calibration commands include ZQ Calibration Long command executed during power-on and initialization processes, and
ZQ Calibration Short command executed regularly during operation.
Table 1-3 ZQ Calibration Commands and their Execution Timings
Command
When to Issue
ZQCL (ZQ Calibration Long)
Power on/initialization
ZQCS (ZQ Calibration Short)
During operation
User's Manual E1503E10 (Ver.1.0)
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Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
CHAPTER 1
FEATURES OF DDR3 SDRAM (COMPARISON OF MAIN SPECIFICATIONS OF DDR, DDR2, AND DDR3)
1.1.11 CLK-DQS Timing De-skew Mechanism
The DDR3 SDRAM memory module has introduced the fly-by topology (shown in figure 1-6) for the CMD, ADD and CLK
signals to improve signal quality.
DDR3 DIMM
C
T
D7
D6
D5
D4
D3
D2
D1
D0
B
A
Controller
CMD/ADD/CLK
DQ/DM/DQS
Figure 1-6 Fly-by Topology and Timing De-skew
This topology improves signal quality, but generates a difference in flight time between DQ signal and CMD/ADD/CLK signals
(maximal at C in figure 1-6). Therefore, the controller must adjust the output timing of each signal. To this end, DDR3 is
provided with the timing de-skew mechanism.
− Read leveling
DDR3 SDRAM outputs the predetermined data pattern. The controller adjusts the DQ/DQS capture timing using the multi
purpose register (MPR).
− Write leveling
DDR3 SDRAM outputs the CLK-DQS skew information. The controller adjusts signal timings using the skew information so
that the CMD, ADD, and CLK signals arrive at DDR3 at the same time as the DQ, DM, and DQS signals.
User's Manual E1503E10 (Ver.1.0)
12
Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
CHAPTER 1
FEATURES OF DDR3 SDRAM (COMPARISON OF MAIN SPECIFICATIONS OF DDR, DDR2, AND DDR3)
1.1.12 Write Leveling
diff_Clock
Source
diff_DQS
diff_Clock
Destination
(DQS early)
diff_DQS
DQ
X
0
0
diff_Clock
Destination
(DQS delay)
diff_DQS
DQ
X
1
1
Write leveling concept
Figure 1-7 Conceptual Diagram of Write Leveling
エラー!
− Adjustment sequence
(1) Set write leveling to "enabled" in MR1 with the mode register set command.
(2) In write leveling mode, DDR3 samples the CLK signal at the rising edge of DQS and outputs the information from the
DQ pin.
(3) Shift the DQS timing outputted from the controller. When CLK and DQS arrive at the destination at the same time, the DQ
output changes.
User's Manual E1503E10 (Ver.1.0)
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Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
CHAPTER 1
FEATURES OF DDR3 SDRAM (COMPARISON OF MAIN SPECIFICATIONS OF DDR, DDR2, AND DDR3)
[Description]
The DRAM feeds back the current status on the DQ pin (0: early, 1: late).
Based on this result, make a judgment and adjust the timing on the system side.
This function is always active while it is enabled by the setting. Therefore, disable this function after the adjustment.
Source
CPU
Destination
DQS
DRAM
CLK
Feed back from DQ
[Legend]
Source:
Controller side
Destination: DDR3 side
Figure 1-8 Conceptual Diagram
User's Manual E1503E10 (Ver.1.0)
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Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
CHAPTER 1
FEATURES OF DDR3 SDRAM (COMPARISON OF MAIN SPECIFICATIONS OF DDR, DDR2, AND DDR3)
1.1.13 Multi Purpose Register (MPR)
DDR2
T-Branch Topology
Controller
DDR3
Fly-by Topology
Controller
MPR (DRAM)
Output known pattern (set by MR)
Burst length:
8
(EXP.)
Burst order:
0, 1, 2, 3, 4, 5, 6, 7
Pre-defined pattern: [0, 1, 0, 1, 0, 1, 0, 1]
Read leveling (Controller)
Estimate skew (delay) of DQ, DQS, and DM
Figure 1-9 Conceptual Diagram of Multi Purpose Register (MPR)
Read leveling is a specification that adjusts the output skew from each DRAM on the controller side. Since DDR3 operates at
high speed, correct data input may not be possible without timing adjustment.
In addition to the memory array, a ROM that retains specific data patterns is provided. The MPR function intended to assist the
read leveling outputs data from the ROM.
The specific data patterns enable timing adjustment during READ operation.
Note: To use MPR, the controller side must be compatible with MPR.
User's Manual E1503E10 (Ver.1.0)
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Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
The information in this document is current as March 2009. The information is subject to change without notice.
NOTES FOR CMOS DEVICES
1
PRECAUTION AGAINST ESD FOR MOS DEVICES
Exposing the MOS devices to a strong electric field can cause destruction of the gate
oxide and ultimately degrade the MOS devices operation. Steps must be taken to stop
generation of static electricity as much as possible, and quickly dissipate it, when once
it has occurred. Environmental control must be adequate. When it is dry, humidifier
should be used. It is recommended to avoid using insulators that easily build static
electricity. MOS devices must be stored and transported in an anti-static container,
static shielding bag or conductive material. All test and measurement tools including
work bench and floor should be grounded. The operator should be grounded using
wrist strap. MOS devices must not be touched with bare hands. Similar precautions
need to be taken for PW boards with semiconductor MOS devices on it.
2
HANDLING OF UNUSED INPUT PINS FOR CMOS DEVICES
No connection for CMOS devices input pins can be a cause of malfunction. If no
connection is provided to the input pins, it is possible that an internal input level may be
generated due to noise, etc., hence causing malfunction. CMOS devices behave
differently than Bipolar or NMOS devices. Input levels of CMOS devices must be fixed
high or low by using a pull-up or pull-down circuitry. Each unused pin should be connected
to VDD or GND with a resistor, if it is considered to have a possibility of being an output
pin. The unused pins must be handled in accordance with the related specifications.
3
STATUS BEFORE INITIALIZATION OF MOS DEVICES
Power-on does not necessarily define initial status of MOS devices. Production process
of MOS does not define the initial operation status of the device. Immediately after the
power source is turned ON, the MOS devices with reset function have not yet been
initialized. Hence, power-on does not guarantee output pin levels, I/O settings or
contents of registers. MOS devices are not initialized until the reset signal is received.
Reset operation must be executed immediately after power-on for MOS devices having
reset function.
CME0107
User's Manual E1503E10 (Ver.1.0)
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Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
The information in this document is subject to change without notice. Before using this document, confirm that this is the latest version.
No part of this document may be copied or reproduced in any form or by any means without the prior
written consent of Elpida Memory, Inc.
Elpida Memory, Inc. does not assume any liability for infringement of any intellectual property rights
(including but not limited to patents, copyrights, and circuit layout licenses) of Elpida Memory, Inc. or
third parties by or arising from the use of the products or information listed in this document. No license,
express, implied or otherwise, is granted under any patents, copyrights or other intellectual property
rights of Elpida Memory, Inc. or others.
Descriptions of circuits, software and other related information in this document are provided for
illustrative purposes in semiconductor product operation and application examples. The incorporation of
these circuits, software and information in the design of the customer's equipment shall be done under
the full responsibility of the customer. Elpida Memory, Inc. assumes no responsibility for any losses
incurred by customers or third parties arising from the use of these circuits, software and information.
[Product applications]
Be aware that this product is for use in typical electronic equipment for general-purpose applications.
Elpida Memory, Inc. makes every attempt to ensure that its products are of high quality and reliability.
However, users are instructed to contact Elpida Memory's sales office before using the product in
aerospace, aeronautics, nuclear power, combustion control, transportation, traffic, safety equipment,
medical equipment for life support, or other such application in which especially high quality and
reliability is demanded or where its failure or malfunction may directly threaten human life or cause risk
of bodily injury.
[Product usage]
Design your application so that the product is used within the ranges and conditions guaranteed by
Elpida Memory, Inc., including the maximum ratings, operating supply voltage range, heat radiation
characteristics, installation conditions and other related characteristics. Elpida Memory, Inc. bears no
responsibility for failure or damage when the product is used beyond the guaranteed ranges and
conditions. Even within the guaranteed ranges and conditions, consider normally foreseeable failure
rates or failure modes in semiconductor devices and employ systemic measures such as fail-safes, so
that the equipment incorporating Elpida Memory, Inc. products does not cause bodily injury, fire or other
consequential damage due to the operation of the Elpida Memory, Inc. product.
[Usage environment]
Usage in environments with special characteristics as listed below was not considered in the design.
Accordingly, our company assumes no responsibility for loss of a customer or a third party when used in
environments with the special characteristics listed below.
Example:
1) Usage in liquids, including water, oils, chemicals and organic solvents.
2) Usage in exposure to direct sunlight or the outdoors, or in dusty places.
3) Usage involving exposure to significant amounts of corrosive gas, including sea air, CL 2 , H 2 S, NH 3 ,
SO 2 , and NO x .
4) Usage in environments with static electricity, or strong electromagnetic waves or radiation.
5) Usage in places where dew forms.
6) Usage in environments with mechanical vibration, impact, or stress.
7) Usage near heating elements, igniters, or flammable items.
If you export the products or technology described in this document that are controlled by the Foreign
Exchange and Foreign Trade Law of Japan, you must follow the necessary procedures in accordance
with the relevant laws and regulations of Japan. Also, if you export products/technology controlled by
U.S. export control regulations, or another country's export control laws or regulations, you must follow
the necessary procedures in accordance with such laws or regulations.
If these products/technology are sold, leased, or transferred to a third party, or a third party is granted
license to use these products, that third party must be made aware that they are responsible for
compliance with the relevant laws and regulations.
M01E0706
User's Manual E1503E10 (Ver.1.0)
17
Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.
User's Manual E1503E10 (Ver.1.0)
18
Descriptions in this document are provided only for illustrative purpose in semiconductor product operation and application
examples. Use these information under the full responsibility of the customer. For details about the functions of individual products,
refer to the corresponding data sheet.