memory test 测试原理
存储器测试原理
存储器测试原理
存储器测试是一种用于检验计算机存储器功能和可靠性的方法。
在存储器测试中，通常会对存储器进行读写操作，并通过比较存储器接收和输出的数据来检测是否存在错误。
存储器测试的原理包括以下几个方面：
1. 写入测试：将特定的数据写入存储器的单元中，然后读取并比较存储器输出的数据与原始数据是否一致。
如果一致，则表示存储器单元正常。
2. 读取测试：在存储器的单元中预先写入一些数据，然后从存储器中读取并比较输出的数据是否与预期结果一致。
如果一致，则表示存储器单元正常。
3. 位翻转测试：将存储器中某一个或多个特定位的数据进行翻转，然后读取并比较输出的数据。
如果输出与输入相反，则表示存储器单元对于位翻转具有正确的反应。
4. 重复拷贝测试：将一段特定的数据重复拷贝到存储器的不同单元中，并逐一读取并比较输出的数据。
如果每个单元的输出结果都正确，则表示存储器正常。
5. 边界测试：在存储器的边界处，即首地址和末地址处写入特定的数据，然后读取并比较输出的数据。
如果输出结果正确，则表示存储器对边界情况具有正确的处理能力。
以上是存储器测试的一些基本原理，通过这些原理可以检测存储器中的错误，并保证存储器能够正常工作。
存储器测试通常通过软件或硬件工具进行，以确保计算机系统能够正常运行并提供准确的数据存储和读取功能。
著名内存测试软件memtest的原理与技术深度剖析
Technical Information∙Windows Installation∙Usageo Online Commandso Memory Sizingo Error Displayo Troubleshooting Memory Errorso Execution Time∙Detailed Descriptiono Memory Testing Philosophyo Memtest86 Test Algorithmso Individual Test DescriptionsWindows InstallationFor windows installation begin by downloading either the Pre-Compiled Windows package to build a boot-able floppy disk or an ISO (zip version) to create a boot-able CD-ROM. After the file is downloaded an extract must be done to uncompress the file(s). To extract right click on the downloaded file and select the "Extract All" option. The extract option will let you choose where the files will be extracted to. To build a bootable floppy go the the folder where the files were extracted and click on the Install icon. The floppy disk will appear to be unformatted by Windows after the install is complete.To build a boot-able CD-ROM use your CD burning software to create an image from the un-zipped ISO file. Be sure to use a create from image option. DO not simply copy the file to a CD. Since Memtest86 is a standalone program it does not require any operating system support for execution. It can be used with any PC regardless of what operating system, if any, is installed. The test image may be loaded from a floppy disk or may be loaded via LILO on Linux systems. Any Unix, Windows or DOS system may be used to create a boot floppy or bootable CD-ROM. Return to topOnline CommandsMemtest86 has a limited number of online commands. Online commands provide control over cache settings, error report modes, test selection and test address range. A help bar is displayed at the bottom of the screen listing the available on-line commands.Command Description:ESC Exits the test and does a warm restart via the BIOS.c Enters test configuration menuMenu options are:1) Test selection2) Address Range3) Memory Sizing4) Error Report Mode5) Show DMI Memory Info6) ECC Mode7) CPU Selection Mode8) Redraw Screen9) Adv. OptionsSP Set scroll lock (Stops scrolling of error messages)Note: Testing is stalled when the scroll lock isset and the scroll region is full.CR Clear scroll lock (Enables error message scrolling)Return to topMemory SizingThe BIOS in modern PC's will often reserve several sections of memory for it's use and also to communicate information to the operating system (ie. ACPI tables). It is just as important to test these reserved memory blocks as it is for the remainder of memory. For proper operation all of memory needs to function properly regardless of what the eventual use is. For this reason Memtest86 has been designed to test as much memory as is possible.However, safely and reliably detecting all of the available memory has been problematic. Versions of Memtest86 prior to v2.9 would probe to find where memory is. This works for the vast majority of motherboards but is not 100% reliable. Sometimes the memory size detection is incorrect and worse probing the wrong places can in some cases cause the test to hang or crash. Starting in version 2.9 alternative methods are available for determining memory size. By default the test attempts to get the memory size from the BIOS using the "e820" method. With "e820" the BIOS provides a table of memory segments and identifies what they will be used for. By default Memtest86 will test all of the ram marked as available and also the area reserved for the ACPI tables. This is safe since the test does not use the ACPI tables and the "e820" specifications state that this memory may be reused after the tables have been copied. Although this is a safe default some memory will not be tested.Two additional options are available through online configuration options. The first option (BIOS-All) also uses the "e820" method to obtain a memory map. However, when this option is selected all of the reserved memory segments are tested, regardless of what their intended use is. The only exception is memory segments that begin above 3GB. Testing has shown that these segments are typically not safe to test. The BIOS-All option is more thorough but could be unstable with some motherboards.The third option for memory sizing is the traditional "Probe" method. This is a very thorough but not entirely safe method. In the majority of cases the BIOS-All and Probe methods will return the same memory map. For older BIOS's that do not support the "e820" method there are two additional methods (e801 and e88) for getting the memory size from the BIOS. These methods only provide the amount of extended memory that is available, not a memory table. When thee801 and e88 methods are used the BIOS-All option will not be available. The MemMap field on the display shows what memory size method is in use. Also the RsvdMem field shows how much memory is reserved and is not being tested.Return to topError DisplayMemtest has three options for reporting errors. The default is an an error summary that displays the most relevant error information. The second option is reporting of individual errors. In BadRAM Patterns mode patterns are created for use with the Linux BadRAM feature. This slick feature allows Linux to avoid bad memory pages. Details about the BadRAM feature can be found at http://home.zonnet.nl/vanrein/badramThe error summary mode displays the following information:Error Confidence Value:A value that indicates the validity of the errors being reported withlarger values indicating greater validity. There is a high probabilitythat all errors reported are valid regardless of this value. However,when this value exceeds 100 it is nearly impossible that the reportederrors will be invalid.Lowest Error Address:The lowest address that where an error has been reported.Highest Error Address:The highest address that where an error has been reported.Bits in Error Mask:A mask of all bits that have been in error (hexadecimal).Bits in Error:Total bit in error for all error instances and the min, max and average bit in error of each individual occurrence.Max Contiguous Errors:The maximum of contiguous addresses with errors.ECC Correctable Errors:The number of errors that have been corrected by ECC hardware.Errors per DIMM slot:Error counts are reported for each memory module installed in thesystem. Use the Show DMI Memory Info runtime option fordetailed memory module information.Test Errors:On the right hand side of the screen the number of errors for each test are displayed.For individual errors the following information is displayed when a memory error is detected. An error message is only displayed for errors with a different address or failing bit pattern. All displayed values are in hexadecimal.Tst: Test NumberFailing Address: Failing memory addressGood: Expected data patternBad: Failing data patternErr-Bits: Exclusive or of good and bad data (this shows the position of the failing bit(s)) Count: Number of consecutive errors with the same address and failing bitsReturn to topTroubleshooting Memory ErrorsPlease be aware that not all errors reported by Memtest86 are due to bad memory. The test implicitly tests the CPU, L1 and L2 caches as well as the motherboard. It is impossible for the test to determine what causes the failure to occur. However, most failures will be due to a problem with memory module. When it is not, the only option is to replace parts until the failure is corrected.Once a memory error has been detected, determining the failing SIMM/DIMM module is not a clear cut procedure. With the large number of motherboard vendors and possible combinations of memory slots it would be difficult if not impossible to assemble complete information about how a particular error would map to a failing memory module. However, there are steps that may be taken to determine the failing module. Here are four techniques that you may wish to use:1) Removing modulesThis is simplest method for isolating a failing modules, but may only be employed when one or more modules can be removed from the system. By selectively removing modules from the system and then running the test you will be able to find the bad modules. Be sure to note exactly which modules are in the system when the test passes and when the test fails.2) Rotating modulesWhen none of the modules can be removed then you may wish to rotate mod ules to find the failing one. This technique can only be used if there are three or more modules in the system. Change the location of two modules at a time. For example put the module from slot 1 into slot 2 and put the module from slot 2 in slot 1. Run the test and if either the failing bit or address changes then you know that the failing module is one of the ones just moved. By using several combinations of module movement you should be able to determine which module is failing.3) Replacing modulesIf you are unable to use either of the previous techniques then you are left to selective replacement of modules to find the failure.4) Avoiding allocationThe printing mode for BadRAM patterns is intended to construct boot time parameters for a Linux kernel that is compiled with BadRAM support. This work-around makes it possible for Linux to reliably run with defective RAM. For more information on BadRAM support for Linux, sail to http://home.zonnet.nl/vanrein/badramSometimes memory errors show up due to component incompatibility. A memory module may work fine in one system and not in another. This is not uncommon and is a source of confusion. In these situations the components are not necessarily bad but have marginal conditions that when combined with other components will cause errors.Often the memory works in a different system or the vendor insists that it is good. In these cases the memory is not necessarily bad but is not able to operate reliably at Athlon speeds. Sometimes more conservative memory timings on the motherboard will correct these errors. In other cases the only option is to replace the memory with better quality, higher speed memory. Don't buy cheap memory and expect it to work with an Athlon! On occasion test 5/8 errors will occur even with name brand memory and a quality motherboard. These errors are legitimate and should be corrected.I am often asked about the reliability of errors reported by Mestest86. In the vast majority of cases errors reported by the test are valid. There are some systems that cause Memtest86 to be confused about the size of memory and it will try to test non-existent memory. This will cause a large number of consecutive addresses to be reported as bad and generally there will be many bits in error. If you have a relatively small number of failing addresses and only one or two bits in error you can be certain that the errors are valid. Also intermittent errors are without exception valid. Frequently memory vendors question if Memtest86 supports their particular memory type or a chipset. Memtest86 is designed to work with all memory types and all chipsets. Only support for ECC requires knowledge of the chipset.All valid memory errors should be corrected. It is possible that a particular error will never show up in normal operation. However, operating with marginal memory is risky and can result in data loss and even disk corruption. Even if there is no overt indication of problems you cannot assume that your system is unaffected. Sometimes intermittent errors can cause problems that do not show up for a long time. You can be sure that Murphy will get you if you know about a memory error and ignore it.Memtest86 can not diagnose many types of PC failures. For example a faulty CPU that causes Windows to crash will most likely just cause Memtest86 to crash in the same way.Return to topExecution TimeThe time required for a complete pass of Memtest86 will vary greatly depending on CPU speed, memory speed and memory size. Memtest86 executes indefinitely. The pass counter increments each time that all of the selected tests have been run. Generally a single pass is sufficient to catch all but the most obscure errors. However, for complete confidence when intermittent errors are suspected testing for a longer period is advised.Return to topMemory Testing PhilosophyThere are many good approaches for testing memory. However, many tests simply throw some patterns at memory without much thought or knowledge of memory architecture or how errors can best be detected. This works fine for hard memory failures but does little to find intermittent errors. BIOS based memory tests are useless for finding intermittent memory errors.Memory chips consist of a large array of tightly packed memory cells, one for each bit of data. The vast majority of the intermittent failures are a result of interaction between these memory cells. Often writing a memory cell can cause one of the adjacent cells to be written with the same data. An effective memory test attempts to test for this condition. Therefore, an ideal strategy for testing memory would be the following:1.write a cell with a zero2.write all of the adjacent cells with a one, one or more times3.check that the first cell still has a zeroIt should be obvious that this strategy requires an exact knowledge of how the memory cells are laid out on the chip. In addition there is a never ending number of possible chip layouts for different chip types and manufacturers making this strategy impractical. However, there are testing algorithms that can approximate this ideal.Return to topMemtest86 Test AlgorithmsMemtest86 uses two algorithms that provide a reasonable approximation of the ideal test strategy above. The first of these strategies is called moving inversions. The moving inversion test works as follows:1.Fill memory with a pattern2.Starting at the lowest addresso check that the pattern has not changedo write the patterns complemento increment the addresso repeat3.Starting at the highest addresso check that the pattern has not changedo write the patterns complemento decrement the addresso repeatThis algorithm is a good approximation of an ideal memory test but there are some limitations. Most high density chips today store data 4 to 16 bits wide. With chips that are more than one bit wide it is impossible to selectively read or write just one bit. This means that we cannot guarantee that all adjacent cells have been tested for interaction. In this case the best we can do is to use some patterns to insure that all adjacent cells have at least been written with all possible one and zero combinations.It can also be seen that caching, buffering and out of order execution will interfere with the moving inversions algorithm and make less effective. It is possible to turn off cache but the memory buffering in new high performance chips can not be disabled. To address this limitation a new algorithm I call Modulo-X was created. This algorithm is not affected by cache or buffering. The algorithm works as follows:1.For starting offsets of 0 - 20 doo write every 20th location with a patterno write all other locations with the patterns complemento repeat above one or more timeso check every 20th location for the patternThis algorithm accomplishes nearly the same level of adjacency testing as moving inversions but is not affected by caching or buffering. Since separate write passes (1a, 1b) and the read pass (1c) are done for all of memory we can be assured that all of the buffers and cache have been flushed between passes. The selection of 20 as the stride size was somewhat arbitrary. Larger strides may be more effective but would take longer to execute. The choice of 20 seemed to be a reasonable compromise between speed and thoroughness.Return to topIndividual Test DescriptionsMemtest86 executes a series of numbered test sections to check for errors. These test sections consist of a combination of test algorithm, data pattern and cache setting. The execution order for these tests were arranged so that errors will be detected as rapidly as possible. A description of each of the test sections follows:Test 0 [Address test, walking ones, no cache]Tests all address bits in all memory banks by using a walking ones address pattern.Test 1 [Address test, own address]Each address is written with its own address and then is checked for consistency. In theory previous tests should have caught any memory addressing problems. This test should catch any addressing errors that somehow were not previously detected.Test 2 [Moving inversions, ones&zeros]This test uses the moving inversions algorithm with patterns of all ones and zeros. Cache is enabled even though it interferes to some degree with the test algorithm. With cache enabled this test does not take long and should quickly find all "hard" errors and some more subtle errors. This test is only a quick check.Test 3 [Moving inversions, 8 bit pat]This is the same as test one but uses a 8 bit wide pattern of "walking" ones and zeros. This test will better detect subtle errors in "wide" memory chips. A total of 20 data patterns are used. Test 4 [Moving inversions, random pattern]Test 4 uses the same algorithm as test 1 but the data pattern is a random number and it's complement. This test is particularly effective in finding difficult to detect data sensitive errors.A total of 60 patterns are used. The random number sequence is different with each pass so multiple passes increase effectiveness.Test 5 [Block move, 64 moves]This test stresses memory by using block move (movsl) instructions and is based on Robert Redelmeier's burnBX test. Memory is initialized with shifting patterns that are inverted every 8 bytes. Then 4mb blocks of memory are moved around using the movsl instruction. After the moves are completed the data patterns are checked. Because the data is checked only after the memory moves are completed it is not possible to know where the error occurred. The addresses reported are only for where the bad pattern was found. Since the moves are constrained to a 8mbsegment of memory the failing address will always be less than 8mb away from the reported address. Errors from this test are not used to calculate BadRAM patterns.Test 6 [Moving inversions, 32 bit pat]This is a variation of the moving inversions algorithm that shifts the data pattern left one bit for each successive address. The starting bit position is shifted left for each pass. To use all possible data patterns 32 passes are required. This test is quite effective at detecting data sensitive errors but the execution time is long.Test 7 [Random number sequence]This test writes a series of random numbers into memory. By resetting the seed for the random number the same sequence of number can be created for a reference. The initial pattern is checked and then complemented and checked again on the next pass. However, unlike the moving inversions test writing and checking can only be done in the forward direction.Test 8 [Modulo 20, ones&zeros]Using the Modulo-X algorithm should uncover errors that are not detected by moving inversions due to cache and buffering interference with the the algorithm. As with test one only ones and zeros are used for data patterns.Test 9 [Bit fade test, 90 min, 2 patterns]The bit fade test initializes all of memory with a pattern and then sleeps for 90 minutes. Then memory is examined to see if any memory bits have changed. All ones and all zero patterns are used. This test takes 3 hours to complete. The Bit Fade test is not included in the normal test sequence and must be run manually via the runtime configuration menu.Return to top。
内存检测 原理
内存检测原理
内存检测是一种用于测试计算机内存是否正常工作的方法。
它的原理是通过对内存中存储的数据进行读取、写入和比较，来验证内存是否能够正确地存储和检索数据。
在内存检测的过程中，需要使用一个特定的程序来执行测试。
这个测试程序会向内存中写入一些特定的模式数据，并随后再读取出来，然后将读取的数据与写入的数据进行比较。
如果读取的数据与写入的数据不一致，就说明内存中存在问题，可能是因为存储器芯片损坏、接触不良、或者其他硬件故障导致的。
内存检测通常分为两种类型：稳定性测试和模拟测试。
稳定性测试是通过在内存中循环执行一些特定模式的字节，来测试内存是否能够长时间稳定地工作。
这种测试能够检测出内存是否容易产生错误，是否存在存储或检索数据时的干扰、噪音或电压问题。
模拟测试则是通过模拟真实的计算机使用情况，对内存进行测试。
这种测试会模拟计算机运行应用程序时对内存的读写操作，来检测内存中是否存在任何错误或故障。
内存检测对于确保计算机系统的稳定性和可靠性非常重要。
通过定期进行内存检测，可以及时发现并解决潜在的内存问题，提高计算机系统的性能和可靠性。
memory test 项目介绍
MemTest86 Test AlgorithmsMemTest86 uses two algorithms that provide a reasonable approximation of the ideal test strategy above. The first of these strategies is called moving inversions. The moving inversion test works as follows:1. Fill memory with a pattern2. Starting at the lowest addresso check that the pattern has not changedo write the patterns complemento increment the addresso repeat3. Starting at the highest addresso check that the pattern has not changedo write the patterns complemento decrement the addresso repeatThis algorithm is a good approximation of an ideal memory test but there are some limitations. Most high density chips today store data 4 to 16 bits wide. With chips that are more than one bit wide it is impossible to selectively read or write just one bit. This means that we cannot guarantee that all adjacent cells have been tested for interaction. In this case the best we can do is to use some patterns to insure that all adjacent cells have at least been written with all possible one and zero combinations.It can also be seen that caching, buffering and out of order execution will interfere with the moving inversions algorithm and make less effective. It is possible to turn off cache but the memory buffering in new high performance chips can not be disabled. To address this limitation a new algorithm I call Modulo-X was created. This algorithm is not affected by cache or buffering. The algorithm works as follows:1. For starting offsets of 0 - 20 doo write every 20th location with a patterno write all other locations with the patterns complemento repeat above one or more timeso check every 20th location for the patternThis algorithm accomplishes nearly the same level of adjacency testing as moving inversions but is not affected by caching or buffering. Since separate write passes (1a, 1b) and the read pass (1c) are done for all of memory we can be assured that all of the buffers and cache have been flushedbetween passes. The selection of 20 as the stride size was somewhat arbitrary. Larger strides may be more effective but would take longer to execute. The choice of 20 seemed to be a reasonable compromise between speed and thoroughness.Individual Test DescriptionsMemTest86 executes a series of numbered test sections to check for errors. These test sections consist of a combination of test algorithm, data pattern and cache setting. The execution order for these tests were arranged so that errors will be detected as rapidly as possible. A description of each of the test sections follows:Test 0 [Address test, walking ones, no cache]Tests all address bits in all memory banks by using a walking ones address pattern.Test 1 [Address test, own address, Sequential]Each address is written with its own address and then is checked for consistency. In theory previous tests should have caught any memory addressing problems. This test should catch any addressing errors that somehow were not previously detected. This test is done sequentially with each available CPU.Test 2 [Address test, own address, Parallel]Same as test 1 but the testing is done in parallel using all CPUs and using overlapping addresses. Test 3 [Moving inversions, ones&zeros, Parallel]This test uses the moving inversions algorithm with patterns of all ones and zeros. Cache is enabled even though it interferes to some degree with the test algorithm. With cache enabled this test does not take long and should quickly find all "hard" errors and some more subtle errors. This is done in parallel using all CPUs.Test 4 [Moving inversions, 8 bit pattern]This is the same as test 3 but uses a 8 bit wide pattern of "walking" ones and zeros. This test will better detect subtle errors in "wide" memory chips.Test 5 [Moving inversions, random pattern]Test 5 uses the same algorithm as test 4 but the data pattern is a random number and it's complement. This test is particularly effective in finding difficult to detect data sensitive errors. The random number sequence is different with each pass so multiple passes increase effectiveness.Test 6 [Block move, 64 moves]This test stresses memory by using block move (movsl) instructions and is based on Robert Redelmeier's burnBX test. Memory is initialized with shifting patterns that are inverted every 8 bytes. Then 4mb blocks of memory are moved around using the movsl instruction. After the moves are completed the data patterns are checked. Because the data is checked only after the memory moves are completed it is not possible to know where the error occurred. The addresses reported are only for where the bad pattern was found. Since the moves are constrained to a 8mb segment of memory the failing address will always be less than 8mb away from the reported address. Errors from this test are not used to calculate BadRAM patterns.Test 7 [Moving inversions, 32 bit pattern]This is a variation of the moving inversions algorithm that shifts the data pattern left one bit for each successive address. The starting bit position is shifted left for each pass. To use all possible data patterns 32 passes are required. This test is quite effective at detecting data sensitive errors but the execution time is long.Test 8 [Random number sequence]This test writes a series of random numbers into memory. By resetting the seed for the random number the same sequence of number can be created for a reference. The initial pattern is checked and then complemented and checked again on the next pass. However, unlike the moving inversions test writing and checking can only be done in the forward direction.Test 9 [Modulo 20, Random pattern]Using the Modulo-X algorithm should uncover errors that are not detected by moving inversions due to cache and buffering interference with the algorithm.Test 10 [Bit fade test, 2 patterns]The bit fade test initializes all of memory with a pattern and then sleeps for a few minutes. Then memory is examined to see if any memory bits have changed. All ones and all zero patterns are used.Test 11 [Random number sequence, 64-bit]This test is the same as Test 8, but native 64-bit instructions are used.Test 12 [Random number sequence, 128-bit]This test is the same as Test 8, but native SIMD (128-bit) instructions are used.Test 13 [Hammer Test]The row hammer test exposes a fundamental defect with RAM modules 2010 or later. This defect can lead to disturbance errors when repeatedly accessing addresses in the same memory bank but different rows in a short period of time. The repeated opening/closing of rows causes charge leakage in adjacent rows, potentially causing bits to flip.This test 'hammers' rows by alternatively reading two addresses in a repeated fashion, then verifying the contents of other addresses for disturbance errors. For more details on DRAM disturbance errors, see Flipping Bits in Memory Without Accessing Them: An Experimental Study of DRAM Disturbance Errors by Yoongu Kim et al.Starting from MemTest86 v6.2, potentially two passes of row hammer testing are performed. On the first pass, address pairs are hammered at the highest possible rate. If errors are detected on the first pass, errors are not immediately reported and a second pass is started. In this pass, address pairs are hammered at a lower rate deemed as the worst case scenario by memory vendors (200K accesses per 64ms). If errors are also detected in this pass, the errors are reported to the user as normal. However, if only the first pass produces an error, a warning message is instead displayed to the user.。
RAM和DDR测试方法的原理与测试案例设计ppt课件
RAM模块根底知识
在RAM的每一个根本存储单位都只能存储0或者1这样 的数据，而CPU存取数据的时候是按照字节〔也就是 8bit〕来存储的，那么RAM终究如何满足CPU的这样 的要求呢？
首先为了能存储1字节(8 bit)的信息,就需求8个1bit RAM根本存储单元堆叠在一同，这也意味着这8颗芯 片被赋予了同样的地址。下面的表示图可以协助他比 较笼统的了解这一点〔以下图所示的图例中仅仅画了 4个存储单元，大家当成8个来看就可以了〕
下面的示意图可以帮助你比较形象的了解这一点下图所示的图例中仅仅画了4个存储单元大家当成8个来看就可以了ram通常这8颗1bit芯片是通过地址总线和数据总线在pcb印刷电路板上连接而成的对于cpu来说它就是一颗8bit的ram芯片而不再是独立的8个1bit芯片
RAM test method
----Warrior Zhu 2006.5.29
1) Fill memory with a pattern
2) Starting at the lowest address
2a check that the pattern has not changed
2b write the patterns complement
2c increment the address
inversions没方法发现的错误，分别填入 “00000000h〞和“FFFFFFFFh〞，检查两次。 8. Moving inversions, 0 & 1, uncached 与第二项测试一样，只是将cache关了，但可 以发现的错误大大添加了。
测试程式的运用及留意点
DOS环境下键入memtest /?得到协助信息：
RAM模块根底知识
内存ATE测试介绍
3
ATE测试
ATE 的工作原理：
被测器件 （DUT）
Input Output
测试系统 （ATE）
Test Program
Results
4
ATE测试设备
高档的ATE测试设备有： ▪ Verigy公司的93K系统 ▪ Advantest公司的T5581/T5585/T5592系统 ▪ KINGTIGER公司的KT－2A PRO系统
DC参数测试
DC 参数 测试
电压参数测试 电流参数测试
测试方法：
1。加电压测电流、 加电流测电压
2。改变DC参数，进行 功能测试，找到P/F 转变点
3。运行pattern程序， 直接对参数测量
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ATE测试简介
DC测试
VSIM
ISV
DC test unit
M
目的：检测芯片的各项电气性能
26
DC参数测试
测试目的： ▪评估DUT的漏电流大小 ▪评估供给DUT工作时所需的电源电流大小
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工程测试
AC参数测试
AC参数测试基本原理： 改变需要测试的参数，重复执行功能 测试，直到测试结果由PASS转为FAIL 为止。记录PASS/FAIL转换点，进行必 要的数学运算，得出需要测试的参数实 际数值。实质是以时间条件为基础来执 行功能测试。
高精度的定时性能 大向量内存 可编程的电流负载 Per Pin的时序与电平/电压 高价格
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T5592简介 T5592测试系统简介
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T5592简介
T5592参数简介
能够测试各种存储器（专用）
最高测试频率可以达到1.066GHz 定时精度达到150ps(OTA) 最大可测试芯片64颗，DDR内存条16条（2Station) Driver与双向口分开，节约成本（存储器特点专门设计）
memtest原理
memtest原理
Memtest原理是利用软件对计算机的内存进行测试和检测，以
验证内存的健康状况和稳定性。
具体原理如下：
1. 内存测试模式：Memtest通过多种测试模式对内存进行测试，包括顺序访问、随机访问等，以覆盖不同的内存读写情况。
2. 数据写入与校验：Memtest首先会将特定的数据模式写入内
存中的每一个存储单元，并记录相应的地址。
然后再进行数据的读取和校验，比较读取到的数据与写入的数据是否一致，以发现潜在的内存错误。
3. 错误检测与纠正：在进行内存读取和校验的过程中，Memtest会检测内存中的位或字节的错误，并标记出错误的位
置和类型。
某些版本的Memtest还可以尝试自动纠正检测到的错误。
4. 循环测试：Memtest会反复执行测试流程，直到设定的测试
时间或循环次数到达。
每一次循环都会记录错误的位置和类型，以帮助用户分析内存的问题。
5. 稳定性测试：除了对内存进行读写测试外，Memtest还可以
进行稳定性测试，以模拟长时间高负载的运行环境。
稳定性测试可以帮助用户发现内存在长时间运行过程中的潜在问题。
总之，Memtest通过对内存进行多次写入、读取和校验，检测
内存中的错误，并记录错误的位置和类型，以帮助用户排除内存相关的问题。
mbist测试方法
mbist测试方法MBIST测试方法简介MBIST（Memory Built-In Self Test）是一种用于测试集成电路中存储器（Memory）的方法。
在集成电路中，存储器是一个重要的组成部分，负责存储和读取数据。
因此，对存储器进行可靠的测试是确保整个集成电路质量的关键步骤之一。
MBIST测试方法是通过在集成电路中嵌入特定的测试电路来实现的。
这些测试电路可以自动地对存储器进行测试，检测和修复其中的故障。
MBIST测试方法有助于提高集成电路的品质和可靠性，减少故障率和成本。
MBIST测试方法的基本原理是利用测试电路生成一系列的测试模式，将这些测试模式写入到存储器中，并读取存储器的输出数据进行比较。
通过分析比较结果，可以检测存储器中的故障，并根据需要进行修复。
MBIST测试方法的优势在于它可以在制造过程中和设备运行时进行测试。
在制造过程中，MBIST测试方法可以用于检测存储器的制造缺陷，例如漏电、短路等。
而在设备运行时，MBIST测试方法可以用于检测存储器的老化和故障，及时修复或替换损坏的存储器。
MBIST测试方法的实施过程包括以下几个步骤：1. 设计测试电路：根据存储器的特性和需求，设计适合的测试电路。
测试电路应能生成多种测试模式，并能检测和修复存储器中的故障。
2. 集成测试电路：将设计好的测试电路集成到集成电路中。
这个过程需要进行电路布线和物理设计，确保测试电路能够正确地与存储器进行连接。
3. 生成测试模式：根据测试电路的设计，生成一系列的测试模式。
这些测试模式可以覆盖存储器的所有操作模式和边界条件，以确保测试的全面性和准确性。
4. 写入测试模式：将生成的测试模式写入到存储器中。
写入测试模式时，需要确保测试模式能够正确地加载到存储器的各个地址位置。
5. 读取比较数据：读取存储器的输出数据，并与预期的结果进行比较。
比较结果可以用于检测存储器中的故障，并确定是否需要修复。
6. 修复存储器：根据比较结果，确定存储器中的故障类型和位置。
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memory test 测试原理
"Memory Test" 测试原理主要有以下几点：
1. 内存检测：Memory Test 主要用于检测计算机内存（内存储器）的性能和稳定性。
内存是计算机中重要的部件之一，它负责暂时存放CPU 的运算数据以及与硬盘等外部存储器交换的数据。
内存性能的好坏直接影响到计算机的运行速度和稳定性。
2. 蓝屏故障排查：当计算机系统频繁出现蓝屏故障时，通过Memory Test 工具检测内存条是否正常。
蓝屏故障往往与内存条故障有关，因此内存测试有助于找出故障原因。
3. 测试方法：Memory Test 通常采用多种测试算法和模式对内存进行测试，如单线程测试、多线程测试、填充测试、空闲测试等。
这些测试算法和模式模拟实际应用场景，对内存进行读写操作，以评估内存的性能和稳定性。
4. 测试结果分析：Memory Test 工具会生成测试报告，包括内存性能指标（如读写速度、延迟等）和稳定性指标（如错误率、崩溃次数等）。
通过分析这些指标，用户可以了解内存的实际情况，判断是否需要更换或维修。
5. 修复和优化：如果Memory Test 检测到内存存在问题，可以尝试使用工具进行修复或优化。
例如，修复内存中的坏点、优化内存分配策略等。
总之，Memory Test 测试原理主要是通过模拟实际应用场景，检测内存的性能和稳定性，从而找出并解决潜在的内存故障。
这有助于保证计算机系统的稳定运行，提高用户体验。