200:
786:
682:
244:). It specifies that for a 0 bit the signal levels will be low–high (assuming an amplitude physical encoding of the data) – with a low level in the first half of the bit period, and a high level in the second half. For a 1 bit the signal levels will be high–low. This is also known as Manchester II or Biphase-L code.
274:
The existence of guaranteed transitions allows the signal to be self-clocking, and also allows the receiver to align correctly; the receiver can identify if it is misaligned by half a bit period, as there will no longer always be a transition during each bit period. The price of these benefits is a
228:
Manchester code always has a transition at the middle of each bit period and may (depending on the information to be transmitted) have a transition at the start of the period also. The direction of the mid-bit transition indicates the data. Transitions at the period boundaries do not carry
686:
1029:
262:
If a
Manchester encoded signal is inverted in communication, it is transformed from one convention to the other. This ambiguity can be overcome by using
169:
Manchester coding's data rate is only half that of a non-coded signal, which limits its usefulness to systems where bandwidth is not an issue, such as a
259:(Ethernet) standards. It states that a logic 0 is represented by a high–low signal sequence and a logic 1 is represented by a low–high signal sequence.
499:
134:
whose frequency is the data rate. Manchester code ensures frequent line voltage transitions, directly proportional to the clock rate; this helps
736:
460:
930:
616:
578:
828:
408:
403:
263:
697:
691:
544:
Manchester encoding introduces some difficult frequency-related problems that make it unsuitable for use at higher data rates.
935:
521:
184:
176:
Manchester encoding introduces difficult frequency-related problems that make it unsuitable for use at higher data rates.
904:
429:
374:
by high-to-low transition (according to G. E. Thomas's convention – in the IEEE 802.3 convention, the reverse is true).
145:
of the encoded signal is not dependent on the data and therefore carries no information. Therefore connections may be
986:
729:
153:
coupled, allowing the signal to be conveyed conveniently by galvanically isolated media (e.g., Ethernet) using a
123:
170:
107:
76:
90:
on 1600 bpi computer tapes before the introduction of 6250 bpi tapes which used the more efficient
976:
95:
489:
240:
The first of these was first published by G. E. Thomas in 1949 and is followed by numerous authors (e.g.,
199:
992:
722:
229:
information. They exist only to place the signal in the correct state to allow the mid-bit transition.
91:
37:
785:
998:
971:
874:
398:
61:
1024:
1003:
884:
844:
556:
150:
818:
813:
808:
632:
276:
146:
87:
69:
33:
608:
598:
570:
560:
869:
760:
714:
612:
594:
574:
461:"Communicating Over Billions of Miles: Long Distance Communications in the Voyager Spacecraft"
248:
158:
80:
899:
864:
765:
663:
154:
894:
180:
111:
966:
909:
889:
879:
803:
775:
241:
135:
131:
1018:
770:
604:
566:
527:
127:
701:
289:
142:
65:
531:
17:
745:
707:
99:
187:
to achieve the same data rate but may be less tolerant of frequency errors and
981:
256:
252:
795:
667:
437:
53:
654:
Forster, R. (2000). "Manchester encoding: Opposing definitions resolved".
79:, where the coding was used for storing data on the magnetic drums of the
68:. Consequently, electrical connections using a Manchester code are easily
961:
951:
388:
Transitions at the start of a period are overhead and don't signify data.
494:
914:
188:
237:
There are two opposing conventions for the representations of data.
60:
is either low then high, or high then low, for equal time. It is a
247:
The second convention is also followed by numerous authors (e.g.,
956:
859:
854:
849:
210:
103:
718:
57:
75:
Manchester code derives its name from its development at the
204:
275:
doubling of the bandwidth requirement compared to simpler
27:
Line code used in early magnetic data storage and
Ethernet
110:. It was and still is used for uploading commands to the
1030:
Department of
Computer Science, University of Manchester
363:
Each bit is transmitted in a fixed time (the period).
923:
837:
793:
753:
191:in the transmitter and receiver reference clocks.
634:Manchester Data Encoding for Radio Communications
203:An example of Manchester encoding showing both
730:
8:
490:"Old, but Still Useful: The Manchester Code"
370:is expressed by a low-to-high transition, a
656:Engineering Science & Education Journal
737:
723:
715:
286:
255:(token bus) and lower speed versions of
198:
420:
122:Manchester coding is a special case of
829:Differential Manchester/biphase (Bi-φ)
233:Conventions for representation of data
205:conventions for representation of data
179:There are more complex codes, such as
809:Non-return-to-zero, level (NRZ/NRZ-L)
359:Encoding conventions are as follows:
7:
814:Non-return-to-zero, inverted (NRZ-I)
483:
481:
161:which cannot convey a DC component.
126:(BPSK), where the data controls the
94:. Manchester code was used in early
86:Manchester code was widely used for
502:from the original on 22 August 2022
56:in which the encoding of each data
385:occur at the midpoint of a period.
25:
931:Carrier-suppressed return-to-zero
819:Non-return-to-zero, space (NRZ-S)
430:"Digital Magnetic Tape Recording"
784:
685: This article incorporates
680:
600:Data and Computer Communications
409:Binary offset carrier modulation
404:Differential Manchester encoding
264:differential Manchester encoding
748:(digital baseband transmission)
698:General Services Administration
98:standards and is still used in
936:Alternate-phase return-to-zero
488:Oed, Richard (22 April 2022).
377:The transitions which signify
1:
905:Eight-to-fourteen modulation
459:Hughes, Mark (2 July 2017).
428:Savard, John J. G. (2018) .
1046:
987:Pulse-amplitude modulation
944:
782:
338:
322:
314:
311:
292:logic (802.3 convention)
124:binary phase-shift keying
982:Pulse modulation methods
865:Alternate mark inversion
171:local area network (LAN)
108:near-field communication
77:University of Manchester
977:Ethernet physical layer
96:Ethernet physical layer
693:Federal Standard 1037C
687:public domain material
225:
993:Pulse-code modulation
910:Delay/Miller encoding
706: (in support of
668:10.1049/esej:20000609
523:Ethernet Technologies
202:
195:Encoding and decoding
157:—a simple one-to-one
92:group-coded recording
70:galvanically isolated
999:Serial communication
972:Digital transmission
875:Coded mark inversion
557:Tanenbaum, Andrew S.
399:Coded mark inversion
288:Encoding data using
62:self-clocking signal
1004:Category:Line codes
885:Hybrid ternary code
845:Conditioned diphase
838:Extended line codes
804:Return to zero (RZ)
704:on 22 January 2022.
534:on 28 December 2018
293:
924:Optical line codes
595:Stallings, William
465:All About Circuits
287:
226:
112:Voyager spacecraft
88:magnetic recording
34:telecommunications
1012:
1011:
870:Modified AMI code
761:Unipolar encoding
562:Computer Networks
357:
356:
307:Manchester value
249:William Stallings
159:pulse transformer
130:of a square wave
81:Manchester Mark 1
18:Manchester coding
16:(Redirected from
1037:
900:64b/66b encoding
788:
766:Bipolar encoding
739:
732:
725:
716:
711:
705:
700:. Archived from
684:
683:
672:
671:
651:
645:
644:
643:
641:
629:
623:
622:
603:(7th ed.).
591:
585:
584:
565:(4th ed.).
553:
547:
546:
541:
539:
530:, archived from
518:
512:
511:
509:
507:
485:
476:
475:
473:
471:
456:
450:
449:
447:
445:
436:. Archived from
425:
384:
380:
373:
369:
294:
279:coding schemes.
251:) as well as by
224:
183:, that use less
155:network isolator
21:
1045:
1044:
1040:
1039:
1038:
1036:
1035:
1034:
1015:
1014:
1013:
1008:
940:
919:
895:8b/10b encoding
833:
789:
780:
749:
743:
713:
690:
681:
679:
676:
675:
653:
652:
648:
639:
637:
631:
630:
626:
619:
593:
592:
588:
581:
555:
554:
550:
537:
535:
520:
519:
515:
505:
503:
487:
486:
479:
469:
467:
458:
457:
453:
443:
441:
427:
426:
422:
417:
395:
382:
378:
371:
367:
316:
285:
272:
235:
223:
216:
208:
207:, where :
197:
181:8B/10B encoding
167:
120:
44:(also known as
42:Manchester code
28:
23:
22:
15:
12:
11:
5:
1043:
1041:
1033:
1032:
1027:
1017:
1016:
1010:
1009:
1007:
1006:
1001:
996:
990:
984:
979:
974:
969:
967:Digital signal
964:
959:
954:
945:
942:
941:
939:
938:
933:
927:
925:
921:
920:
918:
917:
912:
907:
902:
897:
892:
890:6b/8b encoding
887:
882:
880:MLT-3 encoding
877:
872:
867:
862:
857:
852:
847:
841:
839:
835:
834:
832:
831:
826:
821:
816:
811:
806:
800:
798:
791:
790:
783:
781:
779:
778:
776:Mark and space
773:
768:
763:
757:
755:
751:
750:
744:
742:
741:
734:
727:
719:
677:
674:
673:
662:(6): 278–280.
646:
624:
617:
586:
579:
548:
513:
477:
451:
440:on 2 July 2018
419:
418:
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335:
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328:
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324:
321:
318:
313:
309:
308:
305:
303:
300:
298:
297:Original data
284:
281:
271:
268:
242:Andy Tanenbaum
234:
231:
221:
214:
196:
193:
166:
163:
136:clock recovery
119:
116:
46:phase encoding
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
1042:
1031:
1028:
1026:
1023:
1022:
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1005:
1002:
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997:
994:
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985:
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978:
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947:
946:
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916:
913:
911:
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898:
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871:
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863:
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848:
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843:
842:
840:
836:
830:
827:
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822:
820:
817:
815:
812:
810:
807:
805:
802:
801:
799:
797:
792:
787:
777:
774:
772:
771:On-off keying
769:
767:
764:
762:
759:
758:
756:
754:Main articles
752:
747:
740:
735:
733:
728:
726:
721:
720:
717:
712:
709:
703:
699:
695:
694:
688:
669:
665:
661:
657:
650:
647:
636:
635:
628:
625:
620:
618:0-13-100681-9
614:
610:
606:
605:Prentice Hall
602:
601:
596:
590:
587:
582:
580:0-13-066102-3
576:
572:
568:
567:Prentice Hall
564:
563:
558:
552:
549:
545:
533:
529:
528:Cisco Systems
525:
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73:
71:
67:
63:
59:
55:
51:
47:
43:
39:
35:
30:
19:
948:
823:
702:the original
692:
678:
659:
655:
649:
638:, retrieved
633:
627:
599:
589:
561:
551:
543:
538:12 September
536:, retrieved
532:the original
522:
516:
504:. Retrieved
493:
470:27 September
468:. Retrieved
464:
454:
442:. Retrieved
438:the original
433:
423:
358:
290:exclusive or
273:
261:
246:
239:
236:
227:
218:
209:
178:
175:
168:
151:capacitively
143:DC component
140:
121:
85:
74:
66:DC component
49:
45:
41:
38:data storage
31:
29:
746:Line coding
708:MIL-STD-188
607:. pp.
569:. pp.
219:10100111001
165:Limitations
147:inductively
102:protocols,
100:consumer IR
1025:Line codes
1019:Categories
824:Manchester
796:line codes
506:2 February
415:References
257:IEEE 802.3
253:IEEE 802.4
83:computer.
949:See also:
434:quadibloc
185:bandwidth
54:line code
962:Bit rate
952:Baseband
597:(2004).
559:(2002).
500:Archived
393:See also
283:Encoding
270:Decoding
118:Features
64:with no
609:137–138
571:274–275
495:DigiKey
444:16 July
132:carrier
52:) is a
915:TC-PAM
794:Basic
640:28 May
615:
577:
302:Clock
189:jitter
995:(PCM)
989:(PAM)
689:from
128:phase
48:, or
957:Baud
860:2B1Q
855:4B5B
850:4B3T
642:2018
613:ISBN
575:ISBN
540:2017
508:2023
472:2024
446:2018
315:XOR
211:1337
141:The
106:and
104:RFID
36:and
664:doi
381:or
277:NRZ
149:or
58:bit
32:In
1021::
710:).
696:.
658:.
611:.
573:.
542:,
526:,
498:.
492:.
480:^
463:.
432:.
366:A
353:0
345:1
339:1
334:1
326:0
323:=
320:0
317:⊕
312:0
266:.
217:=
215:10
173:.
138:.
114:.
72:.
50:PE
40:,
738:e
731:t
724:v
670:.
666::
660:9
621:.
583:.
510:.
474:.
448:.
383:1
379:0
372:1
368:0
350:1
342:0
331:1
222:2
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.