Ppt on random access memory

Operating System Unit-4. Memory Management Background Logical versus Physical Address Space Swapping Contiguous Allocation Paging Segmentation Segmentation.

/write/execute privileges Protection bits associated with segments; code sharing occurs at segment level. Since segments vary in length, memory allocation is a dynamic storage-allocation problem. A segmentation example is shown in the following diagram Segmentation with Paging – MULTICS/ the tape head; tens or hundreds of seconds. – Generally say that random access within a tape cartridge is about a thousand times slower than random access on disk. The low cost of tertiary storage is a result of having/


CS 152 / Fall 02 Lec 19.1 CS 152: Computer Architecture and Engineering Lecture 19 Locality and Memory Technologies Randy H. Katz, Instructor Satrajit.

(files) CS 152 / Fall 02 Lec 19.20 Memory Hierarchy Technology  Random Access: “Random” is good: access time is the same for all locations DRAM: Dynamic Random Access Memory -High density, low power, cheap, slow -Dynamic: need to be “refreshed” regularly SRAM: Static Random Access Memory -Low density, high power, expensive, fast -Static: content will last “forever”(until lose power)  “Non-so-randomAccess Technology: Access time varies from location to location and from/


1 Outline for Today Objective –Physical Page Placement matters Power-aware memory Superpages Announcements –Deadline extended (wrong kernel was our fault)

Memory Page  Physical address determines which chip is accessed  Assume non- interleaved memory Addresses 0 to N- 1 to chip 0, N to 2N-1 to chip 1, etc.  Entire virtual memory page in one chip  Virtual memory page allocation influences chip- level locality 33 Page Allocation Polices Virtual to Physical Page Mapping Random/misses –Eight 256Mb chips, total 256MB, non-interleaved 37 Dual-state + Random Allocation (NT Traces)  Active to perform access, return to base state  Nap is best ~85% reduction in E*/


CACHE MEMORY Cache memory, also called CPU memory, is random access memory (RAM) that a computer microprocessor can access more quickly than it can access.

word for a specified match, and to do this for all words simultaneously. Cache memories may employ associative access. Key Characteristics of Computer Memory Systems Three performance parameters are used: Access time (latency): For random-access memory, this is the time it takes to perform a read or write operation. For non-random-access memory, access time is the time it takes to position the read–write mechanism at the desired/


V 0.11 Memory Vocabulary ROM – Read Only Memory - a type of memory that cannot be written, can only be read. Contents determined a manufacture time. –ROM.

Time Programmable, a PROM is OTP if contents can be programmed only once. EEPROM – Electrically Erasable PROM – contents be erased electrically by the user. –Memory is not alterable under ‘normal’ operation. V 0.12 Memory Vocabulary RAM – Random Access Memorymemory that can be both read and written during normal operation. –Contents are non-volatile, will be lost on power off. SRAM – static RAM – has the/


Orange Coast College Business Division Computer Science Department CS 116- Computer Architecture The Memory Hierarchy.

& Modified by M.Malaty and M. Beers) Random Access Memory (RAM) Definitions: – Random access (RAM) From http://www.instantweb.com/foldoc/foldoc.cgi?query=random+access&action=Search http://www.instantweb.com/foldoc/foldoc.cgi?query=random+access&action=Search – (RAM) (Previously "direct-access memory"). A data storage device for which the order of access to different locations does not affect the speed of access. This is in contrast to, say, a magnetic/


ESSES 2003 © 2003, Carla Schlatter Ellis 1 Outline for Today Objective –Power-aware memory Announcements.

Ellis 3 Opportunity: Power Aware DRAM Multiple power states –Fast access, high power –Low power, slow access New take on memory hierarchy How to exploit opportunity? Standby 180mW Active 300mW Power /accessed  Assume non- interleaved memory Addresses 0 to N- 1 to chip 0, N to 2N-1 to chip 1, etc.  Entire virtual memory page in one chip  Virtual memory page allocation influences chip- level locality ESSES 2003 © 2003, Carla Schlatter Ellis 33 Page Allocation Polices Virtual to Physical Page Mapping Random/


Memory Hierarchy CS 282 – KAUST – Spring 2010 Slides by: Mikko Lipasti Muhamed Mudawar.

out Several policies are possible –FIFO (first-in-first-out) –LRU (least recently used) –NMRU (not most recently used) –Pseudo-random (yes, really!) Pick victim within set where a = associativity –If a <= 2, LRU is cheap and easy (1 bit) –If a > 2,/ implementation –Pentium 4 has 64-byte blocks in L1 and 128-byte blocks in L2 41 Two-Level Cache Performance – 1/2 Average Memory Access Time: AMAT = Hit Time L1 + Miss Rate L1  Miss Penalty L1 Miss Penalty for L1 cache in the presence of L2 cache/


CSIT 301 (Blum)1 Memory. CSIT 301 (Blum)2 Random Access Memory Random Access Memory (RAM), a.k.a. main memory is the temporary holding place for code.

. When the power is turned off, the information is lost. CSIT 301 (Blum)4 Blurring the Distinction NVRAM: Non-Volatile Random Access Memory, is RAM that does not lose its data when the power goes off. –A separate power source such as a battery allows/301 (Blum)63 From Wikipedia on DDR3 “DDR3 SDRAM is neither forward nor backward compatible with any earlier type of random access memory (RAM) due to different signaling voltages, timings, and other factors.” CSIT 301 (Blum)64 From Wikipedia on DDR3 With data /


CS194-24 Advanced Operating Systems Structures and Implementation Lecture 12 Paging Memory Allocation and File Systems March 5 th, 2014 Prof. John Kubiatowicz.

Allocation Table (FAT) »FAT contains an entry for each block on the disk »FAT Entries corresponding to blocks of file linked together –Access properies: »Sequential access expensive unless FAT cached in memory »Random access expensive always, but really expensive if FAT not cached in memory Lec 12.37 3/5/14Kubiatowicz CS194-24 ©UCB Fall 2014 Indexed Allocation Indexed Files (Nachos, VMS) –System Allocates file header/


Chapter 4 Cache Memory Computer Organization and Architecture William Stallings 8th Edition.

with the system bus, not the processor. 3. Transfer rate It is the rate at which data can be transferred into or out of a memory unit. For random-access memory, it is equal to 1/(cycle time). For non-random-access memory, the following relationship holds: T N = T A + n/R where T N Average time to read or write N bits T A Average/


Week 3 Object-oriented programming JOptionPane Random Graphics.

throws IOException has been added The throws IOException is necessary because of what the code is going to attempt – get access to something out on the web – a class selfie URLImagePopUp throws IOException The method main() definition starts differently than / Random dice = new Random( ); int a = dice.nextInt(); int b = dice.nextInt(); int c = dice.nextInt(); int d = dice.nextInt(); int e = dice.nextInt(); The initialization expression for the Random variable dice is new Random( ) The expression gets memory /


1 chapter 7 Memory Hierarchies Outline of Lectures on Memory Systems 1. Memory Hierarchies 2. Cache Memory 3. Virtual Memory 4. DEC Alpha ( or Intel Pantium)

the speed offered by the fastest technology processor control Datapath registers on-chip cache second level cache main memory secondary storage (Disk) (DRAM) (SRAM) speed (ns): size (bytes): 9 chapter 7 Memory Technology random access memory –“random” is good, access time is the same for all locations –DRAM: high density, low power, cheap, slow, need to be refreshed regularly –SRAM: low density, high power, expensive, fast, content/


© 2003, Carla Schlatter Ellis Power-Aware Memory Management.

Ellis 5 Opportunity: Power Aware DRAM Multiple power states –Fast access, high power –Low power, slow access New take on memory hierarchy How to exploit opportunity? Standby 180mW Active 300mW Power Down/accessed  Assume non- interleaved memory Addresses 0 to N- 1 to chip 0, N to 2N-1 to chip 1, etc.  Entire virtual memory page in one chip  Virtual memory page allocation influences chip- level locality © 2003, Carla Schlatter Ellis 21 Page Allocation Polices Virtual to Physical Page Mapping Random/


Memory COE 301 / ICS 233 Computer Organization Prof. Muhamed Mudawar College of Computer Sciences and Engineering King Fahd University of Petroleum and.

& CachesICS 233 / COE 301 – Computer Organization© Muhamed Mudawar – slide 48 Next...  Random Access Memory and its Structure  Memory Hierarchy and the need for Cache Memory  The Basics of Caches  Cache Performance and Memory Stall Cycles  Improving Cache Performance  Multilevel Caches Memory Hierarchy & CachesICS 233 / COE 301 – Computer Organization© Muhamed Mudawar – slide 49 Improving Cache Performance  Average Memory Access Time (AMAT) AMAT = Hit time + Miss rate * Miss penalty  Used as/


Principles of Computer Architecture Chapter 4: Memory.

perform transfer – For non-random access memory: time to position hardware mechanism at the desired position Memory Cycle time – Primarily applied to random access memory – Time may be required for the memory to “recover” before next access – Cycle time is (access time + recovery time) Performance (2) Transfer Rate: R bps – Rate at which data can be transferred in/out of memory – For random access memory, R = 1/(memory cycle time) – For non-random access memory, – T N = T/


18-447: Computer Architecture Lecture 22: Memory Hierarchy and Caches Prof. Onur Mutlu Carnegie Mellon University Spring 2013, 3/27/2013.

row read 3. Amplify row data 4. Decode column address & select subset of row Send to output 5. Precharge bit-lines For next access 15 SRAM (Static Random Access Memory) 16 bit-cell array 2 n row x 2 m -col (n  m to minimize overall latency) sense amp and mux 2 m/ time dominated by steps 2, 3 and 5 - step 2 proportional to 2 m - step 3 and 5 proportional to 2 n DRAM (Dynamic Random Access Memory) 17 row enable _bitline bit-cell array 2 n row x 2 m -col (n  m to minimize overall latency) sense amp and mux /


CS152 / Kubiatowicz Lec17.1 4/5/99©UCB Spring 1999 CS152 Computer Architecture and Engineering Lecture 17 Locality and Memory Technology April 5, 1999.

Lec17.15 4/5/99©UCB Spring 1999 Memory Hierarchy Technology °Random Access: “Random” is good: access time is the same for all locations DRAM: Dynamic Random Access Memory -High density, low power, cheap, slow -Dynamic: need to be “refreshed” regularly SRAM: Static Random Access Memory -Low density, high power, expensive, fast -Static: content will last “forever”(until lose power) °“Non-so-randomAccess Technology: Access time varies from location to location and from/


14. Memory testing Motivation for testing memories (4)

) 2. Transition fault (TF) 3a. Coupling fault (CF) 3b. Neighborhood pattern sensitive fault (NPSF) Address Address decoder Memory cell array Read/write logic Data 3.1 Notation for describing faults <…> describes a fault describes a single-cell fault S /5.2 MATS+ MATS+ algorithm: {(w0);(r0,w1);(r1,w0)} Fault coverage AFs detected because MATS+ satisfies Cond. AF (When reads, accessing multiple cells, return a random value) Cond. AF: 1. (rx,…,wx*) and 2. (rx*,…,wx) (1) satisfied by: (r0,w1) and (2)/


CS 5600 Computer Systems Lecture 7: Virtual Memory.

, 2 Assume the cache can store 3 pages 95 When memory accesses are random, its impossible to be smart about caching All memory accesses are to 100% random pages 96 LRU does a better job of keeping “hot” pages in RAM than FIFO or random 80% of memory accesses are for 20% of pages 97 The process sequentially accesses one memory address in 50 pages, then loops When the cache size/


Memory.1 361 Computer Architecture Lecture 16: Memory Systems.

,000s (10s ms)Speed (ns):10s100s GsSize (bytes):KsMs memory.12 Memory Hierarchy Technology °Random Access: “Random” is good: access time is the same for all locations DRAM: Dynamic Random Access Memory -High density, low power, cheap, slow -Dynamic: need to be “refreshed” regularly SRAM: Static Random Access Memory -Low density, high power, expensive, fast -Static: content will last “forever” °“Non-so-randomAccess Technology: Access time varies from location to location and from time/


DAP Spr.‘98 ©UCB 1 Lecture 13: Memory Hierarchy—Ways to Reduce Misses.

Blk X Blk Y Address Space 02^n - 1 Probability of reference DAP Spr.‘98 ©UCB 8 Memory Hierarchy Technology Random Access: –“Random” is good: access time is the same for all locations –DRAM: Dynamic Random Access Memory »High density, low power, cheap, slow »Dynamic: need to be “refreshed” regularly –SRAM: Static Random Access Memory »Low density, high power, expensive, fast »Static: content will last “forever”(until lose power) “Not-so/


TopicF: Static and Dynamic Memories José Nelson Amaral

else it disappears. Dynamic Random Access Memory (DRAM): CMPUT 329 - Computer Organization and Architecture II Random Access Memories (RAMs) A Random-Access Memory (RAM) is so called to contrast with its predecessor, the Serial-Access Memory. In a serial access memory, memory positions become available for /Data outputs CS control inputs OE WE CMPUT 329 - Computer Organization and Architecture II SRAMs (Static Random Access Memories) IO0 IO1 IO7 OE CS1 • D0 D1 D7 2764 HM6264 WE CS2 HM62256 HM628128 HM628512 /


Memory Cache Internal External

instructions to invalidate (flush) cache and write back then invalidate L2 and L3 8-way set-associative Line size 128 bytes Internal Memory Semiconductor Memory Types Semiconductor Memory RAM Misnamed as all semiconductor memory is random access Read/Write Volatile Temporary storage Static or dynamic Memory Cell Operation Functional terminals – they carry electrical signal It sets the state of the cell to 1 or 0. Bits stored/


Computer Organization and Architecture William Stallings 8th Edition

rapidly. The other distinguishing characteristic of RAM is that it is volatile. The two traditional forms of RAM used in computers are DRAM and SRAM. Semiconductor Main Memory Random Access Memory (RAM) Misnamed as all semiconductor memory is random access. Read/Write. Volatile. Temporary storage. Static or dynamic. Dynamic RAM (DRAM) Bits stored as charge in capacitors. Charges leak. Need refreshing even when powered. Simpler construction. Smaller/


William Stallings Computer Organization and Architecture Chapter 4 Internal Memory.

portion of the store yAccess time is independent of location or previous access and is constant ye.g. cache Performance Parameters zAccess time yFor random-access memory x the time it takes to perform a read or write operation. xTime between presenting the address to the memory and getting the valid data yFor non-random-access memory xThe time it takes to position the read-write mechanism at/


Scalable Many-Core Memory Systems Lecture 1, Topic 1: DRAM Basics and DRAM Scaling Prof. Onur Mutlu HiPEAC.

path  DRAM cell loses charge over time  DRAM cell needs to be refreshed  Read Liu et al., “RAIDR: Retention-aware Intelligent DRAM Refresh,” ISCA 2012. 36 row enable _bitline Static random access memory Two cross coupled inverters store a single bit  Feedback path enables the stored value to persist in the “cell”  4 transistors for storage  2 transistors for/


Charles Kime & Thomas Kaminski © 2008 Pearson Education, Inc. (Hyperlinks are active in View Show mode) Chapter 8 – Memory Basics Logic and Computer Design.

information when power turned off Non-volatile – retains information when power turned off Chapter 8 14 Overview  Memory definitions  Random Access Memory (RAM)  Static RAM (SRAM) integrated circuits Cells and slices Cell arrays and coincident selection  Arrays of/ Data output Clock Row Address Column Address RAS CAS Address Output enable Chapter 8 30 Overview  Memory definitions  Random Access Memory (RAM)  Static RAM (SRAM) integrated circuits Cells and slices Cell arrays and coincident selection /


Terms 3 Definitions and Questions. ROM Memory hardware that allows fast access to permanently stored data but prevents addition to or modification of.

and easy to integrate into any CMOS chip. http://www.answers.com/topic/rom RAM Random access memory RAM is considered "random access" because you can access any memory cell directly if you know the row and column that intersect at that cell. http://computer/of RAM- Non-Volatile RAM Nonvolatile (sometimes written as "non-volatile") storage (NVS) - also known as nonvolatile memory or nonvolatile random access memory (NVRAM) - is a form of static RAM whose contents are saved when a computer is turned off or /


Scalable Many-Core Memory Systems Lecture 3, Topic 1: DRAM Basics and DRAM Scaling Prof. Onur Mutlu HiPEAC.

Frequency and Voltage Scaling Performance Effects of Frequency Scaling Frequency Control Algorithm Evaluation and Conclusions 63 Memory Latency Under Load At low load, most time is in array access and bus transfer  small constant offset between bus-frequency latency curves As load increases, / 0 and 1 Walk: Attempts to ensure a single cell storing 1 is surrounded by cells storing 0 Random: Randomly generated data is written to each row 108 Fixed patterns Retention Failure Coverage of Data Patterns 109 A 2Gb/


ENG3640 Microcomputer Interfacing Week #11 Memory Interfacing.

 Slower  Variants  PROM,EPROM  EEPROM, FLASH  Application  Programs  Constants  Codes, e.t.c ENG3640 Fall 201211 Memory Technologies  DRAM: Dynamic Random Access Memory upside: very dense (1 transistor/capacitor per bit) and inexpensive  downside: requires refresh and often not the fastest access times  often used for main memories  SRAM: Static Random Access Memory upside: fast and no refresh required  downside: not so dense (6 transistors per cell) and not/


Chapter 5 Memory Hierarchy Design EEF011 Computer Architecture 計算機結構 December 2004 吳俊興 高雄大學資訊工程學系.

cache, with LRU outperforming the others for smaller caches. FIFO generally outperforms random in the smaller cache sizes Q3 (block replacement): Which block should be replaced on a cache miss? 19 Reads dominate processor cache accesses. E.g. 7% of overall memory traffic are writes while 21% of data cache access are writes Two option we can adopt when writing to the cache: Write/


Aaron Lefohn University of California, Davis GPU Memory Model Overview.

CPU interface –Allocate –Free –Copy CPU  GPU –Copy GPU  CPU –Copy GPU  GPU –Bind for read-only vertex stream access –Bind for read-only random access –Bind for write-only framebuffer access 9 GPU Memory API GPU (shader/kernel) interface –Random-access read –Stream read Vertex Buffers GPU memory for vertex data Vertex data required to initiate render pass Vertex Buffer Vertex Processor Rasterizer Fragment Processor Texture Frame/


Random access memory. Memory Main memory consists of a number of storage locations, each of which is identified by a unique address The ability of the.

. A large word length improves system performance, though may be less efficient on occasions when the full word length is not used Types of main memory There are two types of main memory, Random Access Memory (RAM) and Read Only Memory (ROM) Random Access Memory (RAM) holds its data as long as the computer is switched on All data in RAM is lost when the computer is switched off/


CPE 442 memory.1 Introduction To Computer Architecture CpE 442 Memory System.

-Chip Cache 1s10,000,000s (10s ms)Speed (ns):10s100s GsSize (bytes):KsMs CPE 442 memory.14 Introduction To Computer Architecture Memory Hierarchy Technology °Random Access: “Random” is good: access time is the same for all locations DRAM: Dynamic Random Access Memory -High density, low power, cheap, slow -Dynamic: need to be “refreshed” regularly SRAM: Static Random Access Memory -Low density, high power, expensive, fast -Static: content will last “forever” °“Non-so/


QoS-Aware Memory Systems (Wrap Up) Onur Mutlu July 9, 2013 INRIA.

: A Tale of Two Threads Case Study: Two intensive threads contending 1.random-access 2.streaming 15 Prioritize random-accessPrioritize streaming random-access thread is more easily slowed down 7x prioritized 1x 11x prioritized 1x Which is slowed down more easily? Why are Threads Different? 16 random-access streaming req Bank 1Bank 2Bank 3Bank 4 Memory rows All requests parallel High bank-level parallelism All requests  Same row/


Chapter 12 – Memory Devices Copyright © 2011, 2007, 2004, 2001, 1998 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.

J. Tocci, Neal S. Widmer, Gregory L. Moss 12-10 Semiconductor RAM RAM—random-access memory—means any memory address location is as easily accessible as any other. Used in computers for temporary storage of programs and data—requires fast /electromagnets that could be polarized in either direction. This basic technology has been brought back recently in the form of magnetoresistive random access memory (MRAM). Copyright © 2011, 2007, 2004, 2001, 1998 by Pearson Education, Inc. Upper Saddle River, New Jersey /


Memory Hierarchy and Cache Memory Jennifer Tsay CS 147 Section 3 October 8, 2009.

Tsay CS 147 Section 3 October 8, 2009 Two Basic Types of Memory RAM (Random Access Memory) RAM (Random Access Memory)  Used to store programs and data that computer needs when executing programs  Volatile and loses information once power is turned off 2 Basic Types of Memory ROM (Read-Only Memory) ROM (Read-Only Memory)  Stores critical information necessary to operate the system, such as program necessary to boot computer/


Connectivity A Semi-External Algorithm Analysis: Scan vertex set to load vertices into main memory Scan edge set to carry out algorithm O(scan(|V| + |E|))

do not know the page-replacement strategy? An adversarial page replacement strategy could always evict next block that will be accessed… Cache oblivious model assumes an ideal cache: page replacement is optimal, and cache is fully associative. Assumptions of /et al 79, Chen & Hsiao 84, Normand 96, O’Gorman et al 96, Mukherjee et al 05, … ] 51 Memory Errors Soft Errors: Randomly corrupt bits, but do not leave any physical damage --- cosmic rays Hard Errors: Corrupt bits in a repeatable manner because of a/


Lecture 14 Memory Hierarchy and Cache Design Prof. Mike Schulte Computer Architecture ECE 201.

(Tape) 10,000,000,000s (10s sec) Ts How is the hierarchy managed? Registers Memory –by compiler (programmer?) cache memory –by the hardware memory disks –by the hardware and operating system (virtual memory) –by the programmer (files) Memory Hierarchy Technology Random Access: –“Random” is good: access time is the same for all locations –DRAM: Dynamic Random Access Memory »High density, low power, cheap, slow »Dynamic: need to be “refreshed” regularly –SRAM: Static/


Connectivity A Semi-External Algorithm Analysis: Scan vertex set to load vertices into main memory Scan edge set to carry out algorithm O(scan(|V| + |E|))

do not know the page-replacement strategy? An adversarial page replacement strategy could always evict next block that will be accessed… Cache oblivious model assumes an ideal cache: page replacement is optimal, and cache is fully associative. Assumptions of /et al 79, Chen & Hsiao 84, Normand 96, O’Gorman et al 96, Mukherjee et al 05, … ] 51 Memory Errors Soft Errors: Randomly corrupt bits, but do not leave any physical damage --- cosmic rays Hard Errors: Corrupt bits in a repeatable manner because of a/


Scalable Many-Core Memory Systems Optional Topic 5: Interconnects Prof. Onur Mutlu HiPEAC ACACES Summer School.

X2, FBFly, MECS, MECS-X2 Network sizes64 & 256 terminals RoutingDOR, adaptive Messages64 & 576 bits Synthetic trafficUniform random, bit complement, transpose, self-similar PARSEC benchmarks Blackscholes, Bodytrack, Canneal, Ferret, Fluidanimate, Freqmine, Vip, /: Shared resources  memory access Intra-VM traffic  shared cache access Inter-VM traffic  VM page sharing 263 Conventional NOC QOS 264 Contention scenarios: Shared resources  memory access Intra-VM traffic  shared cache access Inter-VM traffic /


CSC 370 (Blum)1 Memory. CSC 370 (Blum)2 Random Access Memory Random Access Memory (RAM), a.k.a. main memory is the temporary holding place for code that.

CSC 370 (Blum)1 Memory CSC 370 (Blum)2 Random Access Memory Random Access Memory (RAM), a.k.a. main memory is the temporary holding place for code that is being executed, has recently been executed or is soon to be executed/ that it requires power. When the power is turned off, the information is lost. CSC 370 (Blum)4 Blurring the Distinction NVRAM: Non-Volatile Random Access Memory, is RAM that does not lose its data when the power goes off. –A separate power source such as a battery allows the RAM to hold/


Scalable Many-Core Memory Systems Topic 3: Memory Interference and QoS-Aware Memory Systems Prof. Onur Mutlu

: A Tale of Two Threads Case Study: Two intensive threads contending 1.random-access 2.streaming 78 Prioritize random-accessPrioritize streaming random-access thread is more easily slowed down 7x prioritized 1x 11x prioritized 1x Which is slowed down more easily? Why are Threads Different? 79 random-access streaming req Bank 1Bank 2Bank 3Bank 4 Memory rows All requests parallel High bank-level parallelism All requests  Same row/


– 1 – CSCE 513 Fall 2015 Lec07 Memory Hierarchy II Topics Pipelining Review Load-Use Hazard Memory Hierarchy Review Terminology review Basic Equations.

DDR4 SDRAM DDR4 SDRAM, an abbreviation for double data rate fourth generation synchronous dynamic random-access memory, is a type of synchronous dynamic random- access memory (SDRAM) with a high bandwidth ("double data rate") interface. It was released to the market in 2014 abbreviationsynchronous dynamic random- access memorybandwidthdouble data rateabbreviationsynchronous dynamic random- access memorybandwidthdouble data rate Benefits include higher module density and lower voltage requirements, coupled/


CSIT 301 (Blum)1 Memory. CSIT 301 (Blum)2 Random Access Memory Random Access Memory (RAM), a.k.a. main memory is the temporary holding place for code.

CSIT 301 (Blum)1 Memory CSIT 301 (Blum)2 Random Access Memory Random Access Memory (RAM), a.k.a. main memory is the temporary holding place for code that is being executed, has recently been executed or is soon to be / that it requires power. When the power is turned off, the information is lost. CSIT 301 (Blum)4 Blurring the Distinction NVRAM: Non-Volatile Random Access Memory, is RAM that does not lose its data when the power goes off. –A separate power source such as a battery allows the RAM to hold/


Computer Architecture: Main Memory (Part I) Prof. Onur Mutlu Carnegie Mellon University.

path  DRAM cell loses charge over time  DRAM cell needs to be refreshed  Read Liu et al., “RAIDR: Retention-aware Intelligent DRAM Refresh,” ISCA 2012. 38 row enable _bitline Static random access memory Two cross coupled inverters store a single bit  Feedback path enables the stored value to persist in the “cell”  4 transistors for storage  2 transistors for/


Computer Architecture: Main Memory (Part III) Prof. Onur Mutlu Carnegie Mellon University.

Frequency and Voltage Scaling Performance Effects of Frequency Scaling Frequency Control Algorithm Evaluation and Conclusions 66 Memory Latency Under Load At low load, most time is in array access and bus transfer  small constant offset between bus-frequency latency curves As load increases, / 0 and 1 Walk: Attempts to ensure a single cell storing 1 is surrounded by cells storing 0 Random: Randomly generated data is written to each row 111 Fixed patterns Retention Failure Coverage of Data Patterns 112 A 2Gb/


Memory (Part I) Aj.Drusawin Vongpramate Information Technology, Faculty of Science Buriram Rajabhat University.

happens automatically thousands of times per second.­ Types of RAM SRAM: Static random access memory DRAM: Dynamic random access memory FPM DRAM: Fast page mode dynamic random access memory EDO DRAM: Extended data-out dynamic random access memory SDRAM: Synchronous dynamic random access memory Types of RAM DDR SDRAM: Double data rate synchronous dynamic RAM RDRAM: Rambus dynamic random access memory Credit Card Memory PCMCIA Memory Card CMOS RAM VRAM: VideoRAM (SGRAM / GDDR RAM) DRAM Works DRAM works/


Slide 1 Vitaly Shmatikov CS 361S Buffer Overflow and Other Memory Corruption Attacks.

’s key Even if pointer is overwritten, after XORing with key it will dereference to a “randommemory address slide 35 CPU Memory Pointer 0x1234 Data 1. Fetch pointer value 0x1234 2. Access data referenced by pointer Normal Pointer Dereference 0x12340x1340 CPU Memory Corrupted pointer 0x1234 0x1340 Data 1. Fetch pointer value 2. Access attack code referenced by corrupted pointer Attack code [Cowan] slide 36 CPU/


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