01

Developments such as the spread of the Internet and advances in cloud computing have led to an acceleration in the rate at which the volume of data is increasing. It has been predicted that the power consumption of IT-related devices in the year 2025 will account for more than 20% of domestic power consumption nationwide. This has given rise to the promotion of "Green IT" through coordination between industry, the government and academia. "Green IT" refers to the introduction of environmentally-friendly IT products and technologies that offer advantages such as reduced power consumption, enhanced efficiency and improved resource conservation performance. In data-center servers and industrial machinery such as NC machine tools, too, SSDs (Solid State Drive) that offer benefits including low power consumption and high reliability are widely used for HDDs. TDK's new advanced-spec SATA II-compatible SSD SDG3B Series for industrial applications incorporates the memory controller IC "GBDriver RS3 Series," an original in-house development of TDK, and features high-speed access with an effective speed of 190MB/s. Incorporation of features such TDK's original global static wear leveling function and a newly-developed data randomizer function optimizes semiconductor storage life. Moreover, program (erase) counts for all memory blocks can be acquired through "SMART information" in real time, thus facilitating quantitative analysis and forecasting of the drive lifespan. As well as IT-related devices, industrial devices and OA equipment, this is the ideal industrial SSD for SMART grid-related devices including SMART meters.

Advanced SSD leading the "Green IT" Era

Serial ATA 3Gbps SSD

SDG3B series

□ Power Consumption in Data Centers □ Comparison of HDD and SSD Performance

□ Principals of NAND-type Flash Memory Program and Erase Operations

Recording form

Capacity

Bit price

Startup time

Read speed

Write speed

Vibration-resistance

Current consumption

Weight

Endurace

Magnetic recording

◎

◎

○

◎

○

×

×

△

◎

Electric recording

△

×

◎

○

◎

◎

◎

◎

△

HDD SSD

To reduce power consumption at data centers,part of the HDD-centered storage is replaced by SSDs.

Powersupply-related

17％

Others8％

Air conditioning30％

IT devicessuch as servers

45％

Control gate20V 0V

0V 20V

Floating gateSilicon dioxide gatedielectric

Electrons

《Program Operation》

Voltage is applied to the control gate, causing tunnel current to flow through the gate dielectric, resulting in penetration of the floating gate by electrons.

《Erase Operation》

Voltage is applied to the silicon substrate, causing the discharge of electrons accumulated in the floating gate.

Program and erase operations are realized by the passage of electrons through the gate dielectric due to the tunnel effect. However, the number of program (erase) operations in the flash memory is limited due to degradation of the gate dielectric.

Serial ATA 3Gbps SSD SDG3B Series

02

Use of low-power-consumption SSDs is increasing even in data centers

Dramatic increases in the volume of data have created the serious problems of rising power costs in data centers. The majority of power consumption in data centers comprises power consumed by IT devices such as servers and air conditioning used for cooling. To address this situation, data centers are increasingly replacing part of HDD-centered storage with SSDs. This is because, although SSDs that use semiconductor memory involve increased initial costs, they quickly contribute to reduced power consumption and major decreases in running costs. SSDs are storage devices that use NAND-type flash memory. Developed based on MOS-FET technology, the mainstream for ICs and LSIs, for example, the memory cell comprises a structure with a floating gate and control gate in the MOS-FET gate. Unlike HDDs that are magnetic memories, SSDs function on the principal of electric potential recording in the memory cell. When voltage is applied to the control gate, the tunnel effect causes electrons to slip through the silicon dioxide

gate dielectric and penetrate the floating gate. This is the write operation. Once the write operation has been completed, the gate dielectric functions as an energy blocking barrier, ensuring that the electrons cannot escape. This is why SSDs are called non-volatile memories. Erasing is achieved by the application of voltage to the silicon substrate side, drawing the electrons from the floating gate. Although the bit price of SSDs is higher than that of HDDs, the absence of a mechanical structure affords the unit powerful resistance to vibration or shock, for example, and the unit offers many benefits superior to those of HDDs. One disadvantage of SSDs, however, is that the number of program (erase) operations is restricted due to degradation of the gate dielectric caused by the repeated passage of electrons.This is why technologies to address this disadvantage are a critical issue for SSDs.

□ Single Level Cell (SLC), Multi Level Cell (MLC) and Threshold Value Voltage Levels

□ Wear Leveling by Memory Controller IC (Conceptual Drawing)

1-bit cell (2-level cell)

Occurrence of defective block　

Concentration of programming in a specific block degrades memory cells and renders the block defective.

The special controller IC algorithm distributes data to avoid concentrations of programming in specific blocks.

VＩＮ(V)

(0)

(1)

Bit count

(0、1)

(0、0)

(1、0)

(1、1)

Bit count

VＩＮ(V)

2-bit cell (4-level cell)

SLC MLC

SSDs using an MLC flash memory are inexpensive, but have short lifespans. SLC is the mainstream type for SSDs for industrial use where there is a need for high reliability and endurance.

《Program》

《Program》

Wear leveling Wear leveling

《Program》

Threshold Value Voltage Level

(Determined in accordance with the electric charge volume injected in the floating gate)

Serial ATA 3Gbps SSD SDG3B Series

03

Highly-reliable SLC-type flash memories are the mainstream for industrial applications

There are two types of NAND-type flash memory: SLC (Single Level Cell) and MLC (Multi Level Cell). In an SLC, one bit of information (0 or 1) is recorded in one transistor memory cell. On the other hand, in an MLC, voltage judgment threshold levels are subdivided to enable programing of multiple bits of information, for example (00, 01, 10, 11) in one transistor cell. An MLC can record twice the amount of information as an SLC within the same chip size and, therefore, offers advantages in terms of cost. Widely used in mobile phones and mobile music players, for example, in terms of factors such volumes shipped and monetary base, the MLC type is by far the more prominent of the two. However, as mentioned earlier, the number of program (erase) operations possible in a flash memory is limited. While the MLC type offers a low bit cost, it is capable of only just under 2,000 program (erase) operations and its data retention is set for only approximately one year. On the other hand, the SLC type is capable of 50 thousand program (erase) operations and its data retention is set for approximately ten years. This is why SLC is the main type used for applications such as industrial devices where the need is for high-speed, high-frequency programming and

reliability. Despite this, however, compared to an HDD that is capable of an unlimited number of program (erase) operations, the limited endurance of 50 thousand operations per block imposed by the SLC type is far too low. A technology known as wear leveling plays a central role in resolving this problem. Excessive concentration of program (erase) operations in a specific block causes damage to the gate dielectric ultimately rendering writing impossible.Wear leveling is a technology that solves this problem by averaging the program (erase) count in each memory block using a dedicated algorithm, thereby leveling the wear on memory cell. Wear leveling comprises two types, the static type and the dynamic type. The dynamic wear leveling approach ignores the program (erase) operation count and writes new data in memory blocks one after the other where no data has been written. Meanwhile, the static wear leveling approach keeps track of program (erase) operation counts and writes data in memory blocks with the fewest possible number of program (erase) operations. In addition, when necessary, data in blocks where data has not been programmed (erased) may be transferred to another block to level the program (erase) operation count.

□ Conceptual Drawing of Global Static Wear Leveling ("TDK Smart Swap")

□ SATA II-compatible SSD Internal Blocks

Static wear leveling is implemented in areas where there is a major difference in program (erase) operation counts between physical memories blocks

The capability to set static wear leveling areas freely as desired enables realization of optimum write dispersal that makes use of the advantages of both the dynamic and static approaches.

Dynamic wear leveling is implemented in areas where there is a minor difference in program (erase) operation counts between physical memories blocks(erase) operation counts between physical memories blocks

SATAconnector

Flash memory interfaceSATA3.0Gbps

Power supplyconnector

《SATA II-compatible SSD SDGB3 Series》

Memory controller ICGBDriver RS3

Flash memoryLC filter

Power ONReset

Memory controller IC(e.g. GBDriver RS3)

crystal oscillator

Flash memory

LC filter

Read-only area

Dynamic wear leveling

Static wear leveling (Smart Swap)

Programming area Unused

Read-only area Programming area Unused

Dual regulator

Serial ATA 3Gbps SSD SDG3B Series

04

Global Static Wear Leveling, an Original Development of TDK

As a flash memory wear leveling approach, the static type is superior to the dynamic type. However, some types of SSD feature a limited scope of static wear leveling within the same chip. In such cases when programming becomes concentrated in a specific area, wear worsens in a specific chip, presenting the possibility of a shorter lifespan that anticipated. To cope with this problem, TDK has realized a global static wear leveling method called "TDK Smart Swap" that makes use of an original algorithm developed by TDK. The number of program (erase) operations in all flash memory areas (all blocks) is counted and, at the same time, leveled memory block programming (erasing) is implemented. In addition, fixed (“cold”) areas for OS or FAT are regularly leveled with no limitation of flash memory chip or zone restrictions. The memory controller IC mounted together with the flash memory greatly affects factors such as SSD endurance and reliability. The "GBDriver RS3 Series" memory controller IC, an original in-house development of TDK, is furnished with a wide diversity of advanced functions including

not only global static wear leveling, but also compatibility with S.M.A.R.T commands that enables verification of the number of program(erase)operations in all flash memory blocks and accurate control. TDK's SATA II-compatible SSD SDGB3 Series is a new SSD product for industrial use that employs this GBDriver RS3 Series. Although not furnished with a cache memory, this product realizes radically enhanced flash memory endurance as well as high-speed access with an effective speed of 190MB/s. Moreover, in addition to a conventional auto-recovery function and power shutdown algorithm, the unit is also mounted with a robust ECC function and an auto-refresh function that look ahead to the future. The SATA II-compatible SSD SDGB3 Series demonstrates outstanding performance as a highly-reliable storage device that can replace HDDs in all fields of industry including data center servers, machine tools, OA equipment, communication infrastructures, automatic ticket vending machines, ATM terminals and SMART meters.

【Data to be written】 【Actual write status in NAND】0 　 0 　 0 　 0 　 0 　 0 　 0 　 0

0 　 0 　 0 　 0 　 0 　 0 　 0 　 0

0 　 0 　 0 　 0 　 0 　 0 　 0 　 0

0 　 0 　 0 　 0 　 0 　 0 　 0 　 0

1 　 1 　 1 　 1 　 1 　 1 　 1 　 1

1 　 1 　 1 　 1 　 1 　 1 　 1 　 1

1 　 1 　 1 　 1 　 1 　 1 　 1 　 1

1 　 1 　 1 　 1 　 1 　 1 　 1 　 1

0 　 1 　 0 　 0 　 1 　 0 　 1 　 0

0 　 1 　 0 　 1 　 1 　 0 　 1 　 0

0 　 1 　 1 　 0 　 1 　 0 　 0 　 1

0 　 1 　 0 　 1 　 0 　 0 　 1 　 0

1 　 0 　 1 　 0 　 0 　 1 　 0 　 1

1 　 0 　 1 　 0 　 0 　 1 　 0 　 1

1 　 0 　 0 　 1 　 0 　 1 　 0 　 0

1 　 0 　 0 　 1 　 0 　 0 　 1 　 1

When same bit is repeated, inter-cell interference in the HAND heightens the risk of electric potential fluctuations in the cell, resulting in bit error

By writing randomized data,data fluctuations due to inter-cell interference are avoided.

Write operation

Read operationRandomized data isdecrypted and read

Data is randomizedand written

Electric potential fluctuationin the floating gate

Occurrence of bit error

1. Occurrence of ECC error2. Changing reading threshold and executing retry3. No ECC errors, OK

Changingreadingthreshold

Block 0

Block xxx

Detection ofcorrectablebit error

Data in all blocks is checked regularly.Before bit errors accumulate and correction becomes impossible,data is restored to pre-empt the occurrence of errors.

Regular all-blockread & ECC check

Error correction &bit error restored

Data Randomizer Function: This function reduces the number of ECC booting by error-resistant write operations.

Read-retry (Re-read) Function: This function reduces the program (erase) count by cutting down the number of ECC booting (Optional)

Auto-refresh Function: The SSD auto-refresh function also enhances data reliability

The data randomizer function randomly distributes and records data writing patterns to avoid occurrence of the same data in succession. This is a function essential to the maintenance of data reliability that automatically uses an error-resistant write operation to write data.

The "GBDriver RS3" is furnished with a wide diversity of functions that dramatically enhance the SSD endurance including global static wear leveling. The main functions are introduced below.

While write operation by the data randomizer function reduces the occurrence of data errors, errors still occur, and, when this happens, the ECC is activated to correct errors. However, since ECC is a program (erase) process, implementation of error-correction each time an error is detected will deplete the available program (erase) count and lead to reduced SSD lifespan. For this reason, the GBDriver RS3 is furnished with a read-retry function. When an error occurs, by re-reading the new voltage threshold value parameter, this function is capable of reading correct data without error correction. This read-retry function maintains data reliability and, at the same time, realizes a long SSD lifespan.

Serial ATA 3Gbps SSD SDG3B Series

05

Furnished with a Wide Diversity of Functions to Dramatically Enhance SSD Endurance

Regardless of whether ordinary read or read-retry executed , NAND-type flash memories present the risk of error occurrence (read-disturb error) due to application of sense voltage when the read operation is repeated. To avoid this, the SDG3B Series is equipped with an auto-refresh function. When there is no access from the system, this function serves to automatically refresh internal data to return data to its correct status. In addition, even during auto-refresh processing, the process is aborted when there is a system access, eliminating the risk of delayed response.

Interior of TDK SSD (SDG3B Series)

1. Password lock: Customers may set passwords.

NAND controllerTDK GB Driver RS3

Encryption processing HW

Decryption processing HW

FW(Trim Command)

Because encrypted data is stored in the memory, data read from the memory will be indecipherable.

NAND-typeflash memory

Write

Read

Erase(Trim）

Host

① Password Lock FunctionAn ATA standard security function is furnished to enable customer setting of individual passwords for each of SSDs. Even if all SSD-mounted devices are the same model, or, indeed, because they are the same model, this is an effective function in cases where passwords for mounted SSDs need to be allocated individually (e.g. Cases where an SSD is used with a multi-function printer (MFP) and a fax sending and receiving log for users is stored outside the startup OS).

② AES128 Bit Encryption Function (CBC Mode)The AES (Advanced Encryption Standard) 128 bit encryption function, an advanced block encryption method standardized under the Federal Informa-tion Processing Standard FIPS PUB197 of the American Department of Commerce, encrypts and records data. This function makes it impossible to restore data through reverse engineering, thus realizing a high level of data security. In addition, encryption and decryption processing are executed by the TDK GBDriver RS3 hardware (HW), ensuring that there are no write or read delays.

③ Complete Data Erase Function (Trim command-compatible)Like an HDD, although the normal erase process in an SSD only markes data “erased”, the “erased” data in fact remains. The TDK SSD SDG3B Series

is compatible with ATA standard Trim commands and is capable of total erasing of unneeded data.

□ Three functions to inhibit unauthorized copying

2. Encryption function

3. ALL data erase

Serial ATA 3Gbps SSD SDG3B Series

06

Robust security functions also furnished to cope with problems such as data falsification, leakage and unauthorized copying

Incidents such as leakage of confidential information such as personal data and information on business operations can expose a company to serious damage to management caused by risks of damage to brand image, loss of trust and high compensation costs. Moreover, such incidents can lead to

fatal damage caused by leakage of intellectual assets such as design information, To cope with these security risks, the TDK SSD SDG3B Series is furnished with three functions designed to inhibit data falsification, leakage and unauthorized copying.

□ "TDK SMART"download　http://www.tdk.co.jp/memorycontroller_e/mem01000.htm

"Visualization" → "Link" → Realize high reliability “all together”In many cases, determining the timing of replacement of maintenance of equipment such as data server or SMART grid devices is normally a time-consuming process, and in some cases, prior application needs to be made to the relevant offices concerned. TDK has made its lifespan diagnostic software "TDK SMART" available on its homepage. Because "TDK SMART" is completely license-free SSD Life Monitor software, not only SSD-mounted device manufacturers, but also users can share information on factors such as remaining SSD lifespan. "TDK SMART" "visualizes" the SSD lifespan to provide

a communication tool that links users and manufacturers, and is mounted as a function not only on equipment such as data servers and SMART grid devices, but also on all kind of social infrastructure equipment including monetary settlement terminals like ETCs and ATMs and station equipment such as automatic ticket vending machines.

Serial ATA 3Gbps SSD SDG3B Series

07

"TDK SMART"(SSD Life Monitor software) that enables "visualization" of the SSD lifespan

□ Main Features

□ Specifications

Uses NAND-type flash memory control IC TDK GBDriver RS3 developed by TDKHigh-speed accessRobust ECC With global static wear leveling function ("TDK Smart Swap")Accessory SSD Life Monitor software "TDK SMART"Reinforced durability against power disconnectionAuto-refresh functionData randomizer functionMounted with AES128 bit (Advanced Encryption Standard) encryption functionTrim command compatibleOther functions (Optional)Uses aluminum bodySolution support

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Model

Capacity

Shape

Memory type

Controller

Interface

Transfer

*1) With SLC flash memory. 4-channel interleaved connection. Depends on the system environment.

*2) When flash memory with 8Kbyte/Page structure indicated endurance is used.

SeriesTDK Serial ATAII Interface

SSD(Solid State Drive) RS3 Series

SDG3B Series

2.5inch SATA

TDK GBDriver RS3

Serial ATA Revision 2.6

SATA Gen1: 1.5Gbps、Gen2: 3.0Gbps

8bit/15bit(512Byte)、30bit/44bit(1,024Byte）

15G

1,000G

500,000 hours

0～70℃

190MB/s

70MB/s （Currently under measurement）

（Currently under measurement）

SLC（Single-Level Cell）NAND-type flash memory

MLC（Multi-Level Cell）NAND-type flash memory

8GB/16GB/32GB/64GB 16GB/32GB/64GB/128GB

Error-correcting funftion

Ednurance *2

Vibration resistance

Read（Max）

Write（Max） *1

With/without fixed area, effective blocks×50,000 times (e.g.6.2 billion times for 64GB SSD)

Capable of real-time grasp of drive status through SMART information (Capable of acquisition of program (Erase) count for all memory blocks)

With/without fixed area, effective blocks×1,500 times (e.g.0.19 billion times for 128GB SSD)

Capable of real-time grasp of drive status through SMART information (Capable of acquisition of program (Erase) count for all memory blocks)

Transfer

Impact resistance

MTBF

Operating temperature range

Serial ATA 3Gbps SSD SDG3B Series

08

2012.02.20