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JEDEC memory standards

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The definitions of kilo, giga, and mega based on powers of two are included only to reflect common usage. IEEE/ASTM SI 10-1997 states "This practice frequently leads to confusion and is deprecated." Further confusion results from the popular use of the megabyte representing 1 024 000 bytes to define
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The documentation of modern memory modules, such as the standards for the memory ICs and a reference design of the module requires over one hundred pages. The standards specify the physical and electrical characteristics of the modules, and include the data for computer simulations of the memory
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is maintained by JEDEC committee JC41. This committee consists of members from manufacturers of microprocessors, memory ICs, memory modules, and other components, as well as component integrators, such as video card and personal computer makers. Standard 21 is published in loose-leaf binder
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JEDEC standards and publications are designed to serve the public interest through eliminating misunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper
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Memory modules of the DDR2-SDRAM type are available for laptop, desktop, and server computers in a wide selection of capacities and access speeds. The standards specify memory module label formats for end-user markets. For example:
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JEDEC Standard 100B.01 specifies common terms, units, and other definitions in use in the semiconductor industry. JESC21-C specifies semiconductor memories from the 256 bit static
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The purpose of this Standard is to define the minimum set of requirements for JEDEC compliant 512 Mb through 8 Gb for x4, x8, and x16 DDR3 SDRAM devices.
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The specification cites three prefixes as follows, with the note that these prefixes are included in the document only to reflect common usage.
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is a 1 GB DDR2 Registered DIMM, with address/command parity function, using 2 ranks of x4 SDRAMs operational to PC2-3200 performance with
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kibi (Ki), mebi (Mi), gibi (Gi), and tebi (Ti) as powers of 2, and kilo, mega, giga, and tera as powers of 10. For example,
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product for use by those other than JEDEC members, whether the standard is to be used either domestically or internationally.
295:= 3, tRCD = 3, tRP = 3, using JEDEC SPD revision 1.1, raw card reference design file D revision 2 used for the assembly. 338:
the capacity of the 1.44-MB high-density diskette. An alternative system is found in Amendment 2 to IEC 60027-2:
123:(B) is a binary character string typically operated upon as one unit. It is usually shorter than a computer word. 116:(b) is the smallest unit of information in the binary numeration system and is represented by the digits 0 and 1. 63:(JEDEC) Solid State Technology Association, a semiconductor trade and engineering standardization organization. 625: 369:"Terms, Definitions, and Letter Symbols for Microcomputers, Microprocessors, and Memory Integrated Circuits" 98:
Terms, Definitions, and Letter Symbols for Microcomputers, Microprocessors, and Memory Integrated Circuits
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are the specifications for semiconductor memory circuits and similar storage devices promulgated by the
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The Joint Electron Device Engineering Council characterizes its standardization efforts as follows:
630: 144:"as a prefix to units of semiconductor storage capacity" to designate multiples of the units. 610: 259:
The JEDEC DDR3 SDRAM standard JESD-79-3f uses Mb and Gb to specify binary memory capacity: "
458: 434:"JEDEC dictionary entry: giga (G) (as a prefix to units of semiconductor storage capacity)" 420:"JEDEC dictionary entry: mega (M) (as a prefix to units of semiconductor storage capacity)" 406:"JEDEC dictionary entry: kilo (K) (as a prefix to units of semiconductor storage capacity)" 221: 67: 8: 35:
Please help update this article to reflect recent events or newly available information.
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The document notes that these prefixes are used in their decimal sense for
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The specification contains citations of the commonly used prefixes
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Letter symbols to be used in electrical technology – Part 2
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The JEDEC terms dictionary further includes definitions for the
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It refers to the IEEE/ASTM SI 10-1997 standard as stating that "
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The specification defines the two common units of information:
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Preliminary publication of JEDEC Semiconductor Memory Standard
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EP2-2100 DDR2 SDRAM 32b-SO-DIMM Reference Design Specification
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this practice frequently leads to confusion and is deprecated
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JEDEC Solid State Technology Association (December 2002).
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The December 2002 JEDEC Standard 100B.01 is entitled
215:"Letter symbols to be used in electrical technology" 273:JESD21-C: Configurations for Solid State Memories 617: 128:Unit prefixes for semiconductor storage capacity 77: 482:Double Data Rate (DDR) SDRAM Specification 334:Quote from JEDEC Standard 100B.01, page 8: 362: 360: 91: 61:Joint Electron Device Engineering Council 276:format to accommodate frequent updates. 103: 618: 459:"DDR3 SDRAM STANDARD | JESD79-3F" 357: 511: 52:Electronics industry recommendations 15: 13: 158:): A multiplier equal to 1024 (2). 14: 642: 599: 569: 536: 478: 20: 563: 530: 505: 239:2 tebi Ti tera + binary: (2) = 213:in Amendment 2 of IEC 60027-2, 472: 451: 440: 426: 412: 398: 389: 328: 280:module operating in a system. 1: 351: 289:1GB 2Rx4 PC2-3200P-333-11-D2 7: 316:Timeline of binary prefixes 299: 266: 78:JEDEC standardization goals 10: 647: 201:(2 or K, where K = 1024). 188:): A multiplier equal to 178:(2 or K, where K = 1024). 168:): A multiplier equal to 29:This article needs to be 321: 224:data rates measured in 606:Online JEDEC documents 447:JEDEC dictionary entry 344: 297: 92:JEDEC Standard 100B.01 89: 57:JEDEC memory standards 335: 286: 84: 626:Units of information 222:serial communication 104:Units of information 540:Bit Wide TTL SRAM 461:. JEDEC. Jul 2012 395:Ref. ANSI X3.172. 50: 49: 638: 594: 593: 592: 591: 585: 579:, archived from 578: 567: 561: 560: 559: 558: 552: 546:, archived from 545: 534: 528: 527: 526: 525: 520: 509: 503: 502: 501: 500: 494: 488:, archived from 487: 476: 470: 469: 467: 466: 455: 449: 444: 438: 437: 430: 424: 423: 416: 410: 409: 402: 396: 393: 387: 386: 384: 383: 373: 364: 345: 332: 254: 253: 250: 247: 244: 200: 199: 196: 193: 177: 176: 173: 45: 42: 36: 24: 23: 16: 646: 645: 641: 640: 639: 637: 636: 635: 631:JEDEC standards 616: 615: 602: 597: 589: 587: 583: 576: 568: 564: 556: 554: 550: 543: 535: 531: 523: 521: 518: 510: 506: 498: 496: 492: 485: 477: 473: 464: 462: 457: 456: 452: 445: 441: 432: 431: 427: 418: 417: 413: 404: 403: 399: 394: 390: 381: 379: 371: 365: 358: 354: 349: 348: 333: 329: 324: 302: 269: 251: 248: 245: 242: 240: 233:binary prefixes 211:binary prefixes 197: 194: 191: 189: 174: 171: 169: 130: 106: 94: 80: 53: 46: 40: 37: 34: 25: 21: 12: 11: 5: 644: 634: 633: 628: 614: 613: 608: 601: 600:External links 598: 596: 595: 562: 529: 512:JEDEC (2007), 504: 471: 450: 439: 425: 411: 397: 388: 355: 353: 350: 347: 346: 326: 325: 323: 320: 319: 318: 313: 308: 301: 298: 268: 265: 257: 256: 203: 202: 179: 159: 129: 126: 125: 124: 117: 105: 102: 93: 90: 79: 76: 51: 48: 47: 28: 26: 19: 9: 6: 4: 3: 2: 643: 632: 629: 627: 624: 623: 621: 612: 609: 607: 604: 603: 586:on 2007-09-26 582: 575: 574: 566: 553:on 2003-04-20 549: 542: 541: 533: 517: 516: 508: 495:on 2006-10-02 491: 484: 483: 475: 460: 454: 448: 443: 435: 429: 421: 415: 407: 401: 392: 377: 370: 363: 361: 356: 343: 341: 331: 327: 317: 314: 312: 311:ISO/IEC 80000 309: 307: 304: 303: 296: 294: 290: 285: 281: 277: 274: 271:The standard 264: 262: 238: 237: 236: 234: 229: 227: 223: 218: 216: 212: 208: 187: 183: 180: 167: 163: 160: 157: 153: 150: 149: 148: 145: 143: 139: 135: 122: 118: 115: 111: 110: 109: 101: 99: 88: 83: 75: 73: 69: 64: 62: 58: 44: 32: 27: 18: 17: 588:, retrieved 581:the original 572: 565: 555:, retrieved 548:the original 539: 532: 522:, retrieved 514: 507: 497:, retrieved 490:the original 481: 474: 463:. Retrieved 453: 442: 428: 414: 400: 391: 380:. Retrieved 376:JESD 100B.01 375: 339: 336: 330: 288: 287: 282: 278: 272: 270: 260: 258: 230: 219: 214: 206: 204: 185: 181: 165: 161: 155: 151: 146: 131: 107: 97: 95: 85: 81: 65: 56: 54: 41:January 2013 38: 30: 378:. p. 8 293:CAS Latency 620:Categories 590:2013-08-08 557:2013-08-08 524:2009-04-05 499:2013-08-08 465:2022-08-21 382:2009-04-05 352:References 255:tera: (10) 72:DDR4 SDRAM 306:IEC 60027 74:modules. 300:See also 267:JESD21-C 611:JESD218 570:JEDEC, 537:JEDEC, 479:JEDEC, 31:updated 140:, and 584:(PDF) 577:(PDF) 551:(PDF) 544:(PDF) 519:(PDF) 493:(PDF) 486:(PDF) 372:(PDF) 322:Notes 226:bits 182:giga 162:mega 152:kilo 142:giga 138:mega 134:kilo 121:byte 119:The 112:The 55:The 252:776 249:627 246:511 243:099 198:824 195:741 192:073 175:576 172:048 114:bit 70:to 68:RAM 622:: 374:. 359:^ 263:" 228:. 136:, 468:. 436:. 422:. 408:. 385:. 342:. 241:1 190:1 186:G 184:( 170:1 166:M 164:( 156:K 154:( 43:) 39:( 33:.

Index

Joint Electron Device Engineering Council
RAM
DDR4 SDRAM
bit
byte
kilo
mega
giga
binary prefixes
serial communication
bits
binary prefixes
CAS Latency
IEC 60027
ISO/IEC 80000
Timeline of binary prefixes


"Terms, Definitions, and Letter Symbols for Microcomputers, Microprocessors, and Memory Integrated Circuits"
"JEDEC dictionary entry: kilo (K) (as a prefix to units of semiconductor storage capacity)"
"JEDEC dictionary entry: mega (M) (as a prefix to units of semiconductor storage capacity)"
"JEDEC dictionary entry: giga (G) (as a prefix to units of semiconductor storage capacity)"
JEDEC dictionary entry
"DDR3 SDRAM STANDARD | JESD79-3F"
Double Data Rate (DDR) SDRAM Specification
the original
EP2-2100 DDR2 SDRAM 32b-SO-DIMM Reference Design Specification
Bit Wide TTL SRAM
the original
Preliminary publication of JEDEC Semiconductor Memory Standard

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