Login / Register
Frequently asked questions
Converting the hexadecimal value to binary and then matching it against the associated SPD byte in the appropriate JEDEC SPD specification will provide a translation of what the byte is for and how it is set.
Micron utilizes a proprietary application that generates SPD values for each part number based on engineer’s input and a database of rules. The rules housed within the database are carefully written to ensure that JEDEC SPD specifications are adhered to. This process ensures compatibility and consistency.
The SPD specifications for modules are determined by JEDEC. Micron uses several SPD specifications within JEDEC Standard No. 21-C to determine and generate SPD data for SDRAM, DDR, DDR2, DDR3 and FBDIMM modules. These specifications are available (if ratified) to the public at www.jedec.org. Specifications that have not yet been completed or ratified are available to JEDEC members only.
Serial Presence Detect
The SPD data represents different electrical and physical characteristics of the module. This data is permanently stored in an electrically erasable programmable read-only memory (EEPROM) on the module. A basic input/output system (BIOS) access SPD information through the SMBus. The system BIOS can then use this data to configure the system to optimize the memory that has been installed.
The SPD table shows the hexadecimal values for each byte that is held in the EEPROM on each memory module.
Verilog models can be created for DDR, DDR2, and DDR3 modules by using a Micron-provided wrapper in conjunction with the Verilog model for the DRAM components used on the specific module you're working with. The configurable DIMM model file (ddr_dimm.v, ddr2_module.v, or ddr3_dimm.v) is included in the DRAM Verilog model .zip file download for DDR, DDR2, and DDR3 components. The readme.txt file included in the .zip provides instructions for configuring the DIMM model.
Micron’s modules are manufactured to be hardware-compatible with both parity and non-parity systems. Par_in (parity in) and the high order address signals have a weak (100K-ohm) pull-down resistor to stabilize the inputs from oscillating around the switch point. Err_out (parity error out) is an open drain and should be left as a true no connect unless used in a parity system. The SPD data on a parity module does reflect parity. In rare occasions, the firmware or BIOS of a non-parity system will err on the parity bit in the SPD. For this reason, the system designer should ensure that the firmware of the non-parity system expects or ignores this portion of the SPD data.
It is suggested that models for connectors be acquired from the connector manufacturers to ensure an accurate model. Micron may be able to provide a simple, uncoupled RLC connector model to be used as is or to create your own connector model. Please e-mail DRAM Support to request this model.
As a rule, Gerber and ODB++ files are not provided to customers, because the files contain proprietary information about our design and could be used to mass-produce our product without our consent. There is normally no reason that a customer would need Gerber files. Gerber files are provided to PCB manufacturers to mass-produce PCBs. IBIS, EBD, or board files provide enough information for customers to create models and perform signal integrity simulations.
Micron can provide Hyperlynx models upon request for most modules. Please e-mail DRAM Support with your request and provide the complete part number of the module you are interested in. Please note, it may take up to two weeks to receive the model once your request has been acknowledged.
Micron does not provide VHDL models for modules. We have focused our modeling resources on higher utilized modeling standards such as IBIS, Verilog, and HSPICE. However, alternatives to VHDL models are available: Denali and Synopsys both have libraries of memory components and module models available on their Web sites. These EDA packages may be an alternate way to create behavioral simulations in the absence of VHDL model. Some simulators such as ModelSim provide a dual language option (VHDL and Verilog). To simulate in this manner, a VHDL wrapper can be used around currently available Verilog models.
To discover the model’s supported drive strengths, do the following:
- HSPICE model: Look at the .sp files for information on supported drive strengths and how to select them.
- IBIS model: Do a text search for the [Model Selector] section. This section describes the drive strengths that can be selected for a given input/output or output buffer.
HSPICE model: Look in the readme file for die revision information.
IBIS model: Look at the top of the file for die revision information.
To validate a model to lab measurements, Micron compares several items, such as input capacitance, power and ground clamp diode characteristics, output buffer drive strength, and output buffer slew rates. New Micron models include a quality report that compares model characteristics to lab measurements and data sheet specifications.
Most Micron models contain very few keywords specific to IBIS 4.0. In many cases, the model can be made IBIS 3.2-compliant with a few simple changes. First, change the [IBIS Ver] keyword to 3.2. Next, place a comment character ("|") in front of the "Vref" section under each [Model Spec] keyword. Finally, comment out each [Receiver Thresholds] section.
Having two ranks available to the memory controller is advantageous in terms of both performance and power. For example, while the controller is waiting for a 64-bit word to be available on one rank, the second 64-bit rank can be accessed. This interleaving increases the overall performance of the module. Power can also be reduced on a rank that is not in use, reducing the power consumption of the module.
1.x level model indicates that the model has not been correlated to any lab measurements. Typically, 1.x level models are provided for pre-silicon or pre-production devices. A 2.x level model has been correlated to lab measurements.
A board file is a complete electrical and mechanical representation of a PCB. EBD and ODB++ files are generated from board files. Board files are not to be provided to customers without an NDA since the files contain confidential and proprietary information about the module design.
Gerbers are files sent to PCB manufacturers to produce PCBs. Gerber is a dated term because board shops currently require ODB++ files to mass-produce PCBs. The term Gerber is used loosely. It sometimes refers to any of the files that represent the PCB’s electrical and mechanical characteristics, including EBD, ODB++, and board files. When a customer asks for Gerber files for a module, it is important to determine what specific files they really need.
A rank typically refers to the data bus width of a system. This width is generally 64 or 72 bits. For example, if 8 components with a width of 8 bits each are mounted to a PCB, this creates a module that is 64 bits wide, enabling a 64-bit word to be read out of the module. We refer to this as a "single-rank" module. Sixteen components with a width of 8 bits each can be mounted to a PCB to form two, 64-bit-wide ranks, creating a "dual-rank" module.
A rank typically refers to the data bus width of a system. This width is generally 64 or 72 bits. For example, if 8 components with a width of 8 bits each are mounted to a PCB, this creates a module that is 64 bits wide, enabling a 64-bit word to be read out of the module. We refer to this as a "single-rank" module. Sixteen components with a width of 8 bits each can be mounted to a PCB to form two, 64-bit-wide ranks, creating a "dual-rank" module.
An .ibs or IBIS file is a representation of a circuit meant to be read by a simulation application such as Cadence® Allegro® or HyperLynx®. IBIS (Input/output Buffer Information Specification) is an EIA (Electronic Industries Alliance) standard. IBIS is a text file in a specific format that represents the current versus voltage and voltage vs. time characteristics of the inputs and outputs of a circuit. IBIS models are the preferred files to provide to customers since the files do not contain any proprietary information about the internal makeup of the components. NDAs are not normally required for IBIS files.
Memory controllers can begin an operation in one bank and perform a separate operation in a different bank while the first operation is completing. This interleaving increases the performance of the DRAM as a whole.
Banks are specific to individual DRAM components and refer to sub-arrays within the DRAM component. Ranks are specific to memory modules and refer to a sub-array made of multiple DRAM components.
The complete IBIS model for a module consists of several files:
1. The IBIS models of the DRAM used on that particular module
2. The IBIS models of the PLL, registers, and EEPROMs (as needed)
3. The IBIS model of the resistive parallel terminations on the PC
4. The EBD (electronic board description) file of the PCB. This file references the IBIS file of the terminations mentioned above.
Together, these files provide a complete representation of the PCB.
Board designers often ask this question when they’re looking for a starting point for their CAD drawings or simulations. Because there are so many variables to consider, it is difficult to provide a "correct" answer. Clock speed, 1T or 2T timing, registered or unbuffered modules, and trace impedance are all important factors. Some controllers have on-die termination, some do not. Some controllers have two copies of the command and address bus. All of these factors can affect trace lengths and termination and can affect how acceptable signal integrity is achieved.
Micron technical notes TN-47-01, TN-47-20, and TN-46-14 can be used as a starting point, but trace length and termination must ultimately be proven by simulation and physical testing. Micron provides an online simulator for customers who do not have the expertise or resources to run simulations. The online simulator is on a secure section of Micron.com; visit the following URL to request access: p1vz.pugetpullway.com/simulators.
We have found that it is more efficient to create module models as they are requested by our customers. If you are unable to locate the IBIS model for the module you are interested in, please e-mail your request to DRAM Support.
You can continue to reach your contact at the same phone number and office location. Your contact should provide you with their new Micron email address to use moving forward.
Effective Feb. 28, 2014, Elpida changed its name to Micron Memory Japan and Elpida Akita changed its name to Micron Akita, Inc.
As we continue to integrate Elpida into Micron some of the sales office locations will change. Please contact your local sales representative for further details.
Your sales representative is available to answer any questions you may have and will work closely with you to ensure that all issues are defined and resolved to the greatest degree possible.
Go to p1vz.pugetpullway.com/careers to apply for a job.
Continue working with the same sales and customer service representatives as before. If changes are made to these contacts you will be notified immediately.
Elpida product-related information has been integrated into p1vz.pugetpullway.com. Use these helpful hints for identifying Elpida parts and navigating our expanded part catalogs:
- All Elpida part numbers begin with the letter “E.”
- Elpida parts appear at the beginning of the part catalog because part lists are sorted alphabetically based on the part number.
- Part catalogs are sortable; use the filter at the top of the part catalog to narrow down part listings based on technology, density, or other features.
- Refer to the Elpida part numbering guide for more information about deciphering Elpida part numbers.
The ordering part number will change to include the Package Media designator (Tape & Reel or Tray). A Product Change Notification was issued in December 2013. Please contact your sales representative if you have any additional questions.
For Elpida part information, including access to Elpida-specific part catalogs and data sheets, visit pugetpullway.com/elpidaparts.
At this time, there are no plans to change the logo or part mark on Elpida branded products. If there are any changes, Micron will work to minimize any impact to our customers and will use appropriate channels to communicate those changes to our customers.
Continue any qualifications that are in progress, unless you hear otherwise from your account support team. If you have questions about support or what to qualify, please rely on your existing Micron or Elpida technical contacts for information.
Micron has made changes to the Micron Distribution network. For a complete list of authorized Micron distributors, reference the Micron Authorized Distributor list. Micron Authorized distributors will sell both Micron and Elpida products. If you have any questions or issues ordering products, please send an email to distribution@pugetpullway.com; and we will ensure that someone assists you. If over time, Micron decides to make further changes to its distribution network, we will work proactively with distribution and customers on their supply chain needs.
- Business systems migrate to Micron’s SAP Procurement environment.
- The purchase order layout and numbering will change beginning in March 2014.
- Replacement Micron purchase orders will be created for open Elpida/Rexchip purchase orders between Feb. 28, 2014 to March 7, 2014, and will reference the former Elpida/Rexchp purchase order number.
- The bill-to address on Micron purchase orders may be different than previous Elpida/Rexchip addresses. A letter was distributed to Elpida/Rexchip suppliers the first week of February 2014 with the new legal entity and billing address.
- Third party agreements that are in effect for each of the Elpida legal entities will be assigned to Micron and/or ultimately terminated. Impacted suppliers will be contacted.
- A core team of Micron and former Elpida team members are working to address these agreements. No change is anticipated however you may be contacted by Micron in the event an agreement is impacted.
Micron’s terms and condition will be applicable to all purchases. Generally these are contained in a Purchase Order. For Micron Memory Japan, they are typically contained in a Master Purchase Agreement. However, if you have an existing signed agreement with Elpida, in general, the terms and conditions contained therein will continue to apply until such agreement is modified or its term ends.
We do not currently have a mechanism in place to donate memory. On occasion we have semiconductor equipment available to donate to our university partners.
Go to the "Community Grants" page to download the application and instructions.
Following the directions, submit all necessary forms and information to the Micron Foundation.
We cannot consider incomplete proposals or programs/projects that fall outside our primary funding areas.
Applications for Higher Education grants are by invitation only. To discuss an idea, contact Janine Rush-Byers at (208) 363-3675.
You must be located in a manufacturing site community: U.S. organizations must be located near Boise, ID; organizations near Micron's Manassass, VA; International organizations must be located near Singapore or Avezanno, Italy.
Please contact the Micron Foundation if you are uncertain of your eligibility.
You must show proof of your non-profit status. A completed application must be submitted. See the below section. Priority is given to those programs geared specifically at advancing science, math, and technology.
Schools can participate in these programs at a variety of levels from individual projects to strategic partnerships with multiple levels of involvement. A school's participation is based on the level of fit and mutual interest between Micron and the interested departments at each university.
To explore potential participation for your department, contact Micron's University Relations Manager at university_relations@pugetpullway.com.
Local Community and K-12 grants, contact Kami Faylor (208) 363-3675
Higher Education grants, contact Janine Rush-Byers (208) 363-3675
Yes. Directive 2011/65/EU (replacing the Directive 2002/95/EC), Restriction of the use of certain Hazardous Substances in Electrical and Electronic Equipment (RoHS), does impact Micron's semiconductor products. The purpose of this directive is to restrict the use of certain hazardous substances in electrical and electronic equipment and protect human health and the environment. Micron’s products have always been 5/6 RoHS compliant, meaning they contain Pb solder, but otherwise comply with RoHS regulations (they meet five of six stipulations). Micron’s Pb-free products are completely RoHS compliant.
Micron's RoHS compliant module level products do contain electronic parts that may use Pb for applications exempt from Directive 2011/65/EU (see Article 4, Annex 3). Please contact your sales/marketing representative for more information.
The European Commission FAQ sheet distributed under the Directorate-General Environment may serve as a formal (but not legally binding) point of reference.
Micron’s Pb-free component, die, and wafer-level products do not contain any of the six substances restricted by the China RoHS. Micron’s modules may contain Pb in both not exempted and exempted EU RoHS applications (where not reliable Pb-free alternatives are available in the market).
Micron’s products are not sold directly to consumers. The EPUP and other marking and labeling requirements apply only to the products sold directly on the consumer market. For more information contact your sales/marketing representative.
These substances are not intentionally added by Micron during the manufacturing process but can be present in trace amounts in the raw materials used to manufacture the finished products.
Micron is fully aware of product requirements coming from Regulation 2006/1907/EC, Registration, Evaluation Authorization and Restriction of Chemicals. Micron constantly monitors new additions to the Candidate List and timely verifies if any Substance of Very High Concern is used in the manufacturing processes and the potential impact on the final products. Micron is committed to provide our customers with information about substances in its products as required. For any documentation needs, please contact your sales representative.
In addition to being RoHS compliant, Micron's Green packages do not contain substances that have been identified as harmful to the environment or known to pose serious reliability: bromine, chlorine, antimony containing substances, and inorganic red phosphorus. These substances are not intentionally added to packaging materials such as encapsulants, die attach materials, underfill epoxies, and substrates. The maximum trace amounts of these substances allowable in Micron’s green packages are listed below.
<900 ppm Chlorine
<900 ppm Bromine
<1500 ppm Chlorine & Bromine
<900 ppm Antimony
<100 ppm Red Phosphorus
Please note that while our Pb-free and green products do not contain any intentionally added Pb, our Pb-free parts are not necessarily green, since they may contain halogen or antimony compounds.
*These substances are not intentionally added by Micron during the manufacturing process but can be present in trace amounts in the raw materials used to manufacture the finished products.
Yes, along with our Pb-free product line, Micron also supports RoHS 5/6 products. We recognize that certain applications are exempt from the RoHS directive.
Micron’s full line of RoHS compliant memory products can be found in the part list tables for each product type. To perform a quick compliance check on a single part number, use the "Part Number Search" tool. For information on green products, please contact your local Micron sales representative.
You can find a part-specific RoHS Certificate of Compliance by navigating to the part detail page or using the main products family navigation.
Micron’s green engineering program is RoHS-compliant and conforms with most of the world’s emerging environmental standards, including those in Asia and Europe.
- For solder balls, Micron is replacing tin-lead alloys (Sn36Pb2Ag or Sn37Pb ) with a tin (Sn), silver (Ag), and copper (Cu) alloys (e.g., SAC105, SAC305, SAC405, LF35).
- For solder paste on modules, Micron is replacing Sn37Pb with Sn3.8Ag0.7Cu.
- For leaded TSOP, Micron is replacing 90Sn10Pb with matte Sn plating.
These substitutions ensure Micron’s Pb-free parts are RoHS-compliant. Parts are certified for a surface mount temperature of 260°C.
Micron can currently provide Pb-free and green product to customers who require it. The availability of these products is highly dependent on customer demand, as well as on the availability of "green" non-memory components and materials.
Please contact your local Micron sales representative for more information (look up regional sales representatives on the Sales Network page).
In February of 1997, Micron Technology, Inc., was one of the first companies in the United States to attain certification under the new ISO 14001 Environmental Management Systems Standard. Micron was selected by KEMA Registered Quality, Inc., to be a pilot participant in the ANSI-RAB National Accreditation Program and is one of five U.S. pilot companies who participated in this program.
Certification under ISO 14001 requires conformance with four basic elements:
- implementation of an environmental management system
- assurance that procedures are in place to maintain compliance with applicable regulations
- commitment to continual improvement
- commitment to overall prevention of pollution
ISO 14001 are voluntary international environmental management standards, which ensure that organizations have effective environmental systems. It is the environmental equivalent to the ISO 9000 quality standards. Various countries and companies have implemented the ISO 9000 quality standards worldwide.
In the ISO 14000 process, a company's environmental management systems are audited by third party registrars. Micron was audited by KEMA Registered Quality, Inc. KEMA is a worldwide full-service third party registrar accredited to ISO 9000, QS9000, and ISO 14001 by ANSI-RAB and RvA, as well as being a "Notified Body" for several areas of CE marketing, mandatory product certification of the European Union. KEMA's clients number in the thousands worldwide and include a wide variety of product and service industries. KEMA specializes in the electronics, information technology, and high technology manufacturing areas.
Micron has a very proactive approach to environmental compliance and protection that serves our employees, our customers, and the communities in which we operate. We are proud of both our environmental and worker safety programs. We view compliance to minimum regulations, as a baseline and work to always be better than the minimum regulations require. ISO 14001 is a good fit with our company and culture. The primary force behind the development of standards for environmental management has been the desire for environmental stewardship and accountability. ISO 14001 embodies an approach, which looks beyond regulatory compliance and challenges an organization to take stock of its environmental programs, continually improve, and commit itself to effective processes and pollution prevention. Micron already had most of the elements needed to conform to ISO 14001 in place. We saw this as an opportunity to be recognized for our commitment, level of effort, and record of accomplishments.
Thermal information includes temperature limits and thermal impedance values. Temperature limits do change for IT parts (TC, TJ, and TA), but thermal impedance values (θJA, θJB, and θJC) do not because thermal impedance depends primarily on the package.
Your particular board design should not be a cause of major concern. The pins can handle the VDD voltage regardless of the VDDQ voltage.
The ECC chip(s) should share the same CKE and CS# as the other devices because they are accessed as the same piece of data.
A bank is an array of memory bits. Multiple arrays or banks are contained within a DRAM component. Depending on density, DRAM components may consist of 4 or 8 banks. For example, a bank may consist of 32 million rows, 4 bits across. This would equate to 128 megabits. Four of these banks in a single DRAM component would yield a 512Mb component.
The impedance tolerance of the driver is ±15 percent.
All our 50-series NAND devices and beyond are ONFI-compliant.
ONFI improves time-to-market in two principal ways:
1. It simplifies the design of Flash controllers that support a range of components by improving uniformity in the behavior of the interface to the NAND components.
2. It reduces the design time of Flash components in end-use applications and enables the use of a new generation of NAND components without design or firmware changes.
ONFI stands for Open NAND Flash Interface. ONFI is an industry working group that is dedicated to simplifying the integration of NAND Flash memory into consumer electronic products, computing platforms, and various other applications that require solid state mass storage. The ONFI working group defines standardized component-level interface specifications for NAND Flash. ONFI is also defining module connector and module form factor specifications (similar to DRAM DIMMs) for NAND Flash. For more information, visit www.onfi.org.
ONFI improves the embedded integration of Flash components into a range of products, including many that use Flash today, such as mobile phones, PDAs, MP3 players, and notebooks. It’s likely, however, that the benefits of ONFI 2.1 will first be realized in PC platforms. Because of the significantly faster speeds that ONFI 2.1 delivers, SSDs and caching solutions will be able to deliver substantive benefits for PC platform workloads.