* Kurose and Ross, “Computer Networking”
✚✂✛☎✜✝✢✣✚✂✤✦✥★✧✂✩✫✪✬✧✂✩✮✭✮✛ ✯✝✧✂✰ ✱✳✲✵✴✷✶✹✸✻✺ ✼ ✽✾✶✿✼❁❀❃❂ ✺ ✼✿❄❅✶✹❆✿❆✷❇✿❈❉❈✙❊ ❋❍●✵■✷❏❉❑❁▲✷▼✷◆P❖ ❑✿◗- ✍❘❁❑❁◗
- P❚✿❬
- ✍▼✱▲❖◆✍P✄◗✏◆✍❘✤❙
* Kurose and Ross, Computer Networking - - PDF document
* Kurose and Ross, “Computer Networking”
✚✂✛☎✜✝✢✣✚✂✤✦✥★✧✂✩✫✪✬✧✂✩✮✭✮✛ ✯✝✧✂✰ ✱✳✲✵✴✷✶✹✸✻✺ ✼ ✽✾✶✿✼❁❀❃❂ ✺ ✼✿❄❅✶✹❆✿❆✷❇✿❈❉❈✙❊ ❋❍●✵■✷❏❉❑❁▲✷▼✷◆P❖ ❑✿◗places 1 2 3 4 5 6 7 _ _ 1 _ 1
❢❄❣✄❤❆❤❆✐ ❥✄❦❋❧❍♠✠♥❑♦▼♣✔♦✏q❍❣✓❤❆r✠s ♦❋t✄♠✄❥✠✉✍✈ ✇ ①③②☞④✆⑤ ⑥✁⑦⑧④✁⑨✁⑩✝❶✘❷✼❸✆❹ ❺✍⑦❼❻✝❹ ❺✕④✠❺☛❶✝④✘❸✆❹ ❽✕⑨✁❻ ❾✓④✔❿✮➀☛⑨☞❽✕➁☞❹ ⑥✔❽✍⑥✝➂✄❺✟❶✁④✢❸✆❹ ❺✔➃ ➁ ➀☛⑥✝➁☞❹ ❺✝❹ ⑥✔❽ ➄③➅☞➆✆➇ ➈✁➉⑧➆✁➊✁➋✝➌✠➍❍➎✮➏ ➐✍➉✼➑☛➏ ➐ ➆✏➍✔➒places 1 2 3 4 5 6 7 _ _ 1 _ 1
2nd
_ 1
1st
_ 1 1
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_ 1
➓❄➔✄→❆→❆➣ ↔✄↕❋➙❍➛✠➜❑➝▼➞✔➝✏➟❍➔✓→❆➠✠➡ ➝❋➢✄➛✄↔✠➤✍➥ ➦ ➧▼➨✆➩ ➫ ➫☛➭☛➯✝➲✢➳☛➯✁➲✔➳✁➵✄➸✆➩ ➭ ➺✪➺✟➻✄➭✟➯✁➼✝➭✍➼☛➽✁➭ ➲✔➾✥➽☛➻✮➫ ➫ ➻✁➚✥➩ ➪✟➶✄➭✟➯✁➲✠➼☞➸✁➻✁➹✕➲✢➾ ➘✔➫ ➲ ➲✁➼☞➳☛➯✏➾ ➻✁➚➴➯✝➼✝➺★➼✔➪✍➲☞➹✕➲✆➪✓➪✟➘✁➷✪➸✁➲✔➾✥➻✝➽✓➻✔➪✕➲✁➺places 1 2 3 4 5 6 7 1 1 1 1
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1 1
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1 1
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1 1
➬➱➮❑✃▼❐❮❒✓❰✠Ï Ð✳Ñ✄ÒÔÓ❄❒✓Õ❆ÕÖÏ ×✄❰✳Ø⑧Ñ✄Ù❍✃✏Ú Û❋Ü✍Ý✕Þ✏ß✮à á★á✟â✝ã✁á✓à ä✓å✝â✝ã✔Ý✟æ☛ç✮è✄ã✁á✍á✟â✁ç✏á✟é ã☞Ý✕ä✝ê✓à á✕á ç✔è✢ê✥ç✁ä✟ä✟ã✁æ☛ç✢é ç☞ë✕ç☞ã✔ì ä à á✕ä✟ç✆ì í✔î☛ä☞à Ý☛å✕ç❑à á✍ã☛í☛í☛ç✮å✟á ä✪ç☞ï☞ã☞å✟á✝ì Þ✄á✟â✝ç✢å✝â✝ç✮å✝ð✄ß✆à á ä✓á✟â✁ã✝á å✕ñ☞é✟é ç✁ä✝ò☛ñ✔Ý☛è✏á ñ✘à á ä✏ì ñ☞å✕ã✁á✝à ñ✔Ý✁ó ô▼õ✔ö☞÷☞ø★ù☞ú û✄÷✝ü✟ü☛ý✁ø✥û✠þ☛ÿ✝÷✁þ✁✄✂ þ✁☎✝✆☛ÿ✁÷✟✞✡✠✝û✁ü✁☛✌☞ ✍✔ø✏✎❼þ ✍✒✑✔✓ ✕✏✖✘✗✄✙ ✚✒✛✢✜✌✣✡✚✡✤✟✚✥✛✦✗✦✤✧✛✦★✒✩✄✙ ✪ ✚✥✫✬✜✟✭✯✮✝✰✝✭✢✱✌✪✲✪ ✱✴✳✵✜✌✪✡✛✯✗✴✪✯✗✦✤✄✙ ✶✲✷✯✜✌✶✦✙ ✪ ✸ ✹✏✺✘✻✄✼ ✽✾✼ ✽✥✿✡✻✌❀✒❀✄❁✯❂✢❃✟❄✄✼ ❁✡❅✥❃✦❆✒❇❉❈places 1 2 3 4 5 6 7 1 1 1 1
2nd
1 1
1st
1 1
0th
1 1 places 1 2 3 4 5 6 7 1 1 1
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1
1s t
1
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1 1 Faulty code received Transmitted code
places 1 2 3 4 5 6 7 8 9 1 1 1 1 2 _ _ _ _
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❩●❬✁❬✥❭✾❪✒❫❵❴ ❛✲❭✾❜✒❭✾❝✁❝❡❞✒❬❘❩❣❢✲❢✲❞✒❢▲❤✐❭✾❫❵❭✾❪✒❫✵❴✢❞✒❜ ❥ ❞✒❦■❭✾❝ ❧♥♠✝♦✯♣✢q❵r stq ♦✡✉✁✈✯✇ ①✯②✯♣✡②✟r ③ r q ④❵q ♦✯♣ qtq ♦✯✉✁⑤ ①✡⑥✦✉✲⑦✔r ③ ③✡⑧ ①✢q⑨⑥✯✉✯q ✉✦⑤ qt♣✢⑧⑨✉✌✇ ✇ ①✦✇ ⑩ ❶❸❷❺❹✦❻✢❹✯❼✢❽✌❾✘❿✡❼⑨➀ ➁✯❹❵❹✌➂ ➂ ❿✦➂✘❽✟➃ ❾ ➀ ➂✢➃ ➄✯➅ ➀✡➃ ❿✡❼⑨❿✯➆t➀ ➁✯❹✲❼ ❹✯➀ ➇✧❿✦➂ ➈✵➉✘➃ ➊✘❻✢❿✡❾ ❾✢➃ ➄✟➋ ❹ ➀ ❿✲➊✔❿✯❽✯❹✟➋ ➌♥➍✝➎✯➏✢➐❵➑ ➒t➐ ➎✡➓✥➔⑨➑ →✯➑ ➔✘➣✡➔↔→✢➣✡➔t↕✡➓✌➙✔➛✡➜❵↕✌➑ ➐ ➒✘➐ ➎✯➏✢➐t➎✯➏✡➝ ➓❵➐ ➛✲↕✡➓✥➞ ➎✯➏✡→ ➟✯➓✯➠✁➜ ➛✯➙ ➐ ➎✯➓✁➞ ➛✡➠✦➓❵➐ ➛❵➜ ➏✯➑ ➡✡➠✯➓✡➐ ➓✌➞ ➐✢➑ → ➟✲➏✡→⑨➓✦➙ ➙ ➛✦➙ ➢ ➤➦➥✄➧✡➨✥➩⑨➫ ➭✦➫ ➩✘➯✡➩■➲✡➳t➵ ➧✯➨✲➸t➺ ➻t➻✵➼ ➽ ➾✾➚✌➼ ➪✦➶ ➺ ➽✯➹ ➘✯➴t➷✡➬t➮✡➱ ✃✲❐✢➮✦❒ ❮✔➷✡➬✲❰ Ï✡Ð✡➮✦❰ Ñ ➷✡Ò✦Ï✯Ó Ô✧➷✦❮ Ò✦➴ Õ➦Ö✄×✡Ø✥Ù✦Ú Û✦Ü Ý Þ✯ß à❵á✯âtã ä✯å✁æ á✡ç✦å è♥é✝ê✯ë✢ì✵í✘î✢ï ì✵ð✡ñ✲ì ê✡ñ✥í⑨ò ó✯ò í✘î✡í↔ô✟ò ï ì ë✡ó✡õ ñ✁ð✯ñ✡ì ö✧ñ✡ñ✦ó⑨ì ê✡ñ✁÷✡ò ø ï ìtë✢ó✡ô✒ù ë✡ï ì ñ✦ø ø ú✡ó ñ✯ú✡î✡ï⑨ð✌ò ì ït÷ ú✯ø✔ì ê✯ñ✁õ ú✯ô✯ñ❵ì ú❵÷ ë✦ò ù û➦ü✄ý✡þ✁ÿ✁ ✂ ✄ ☎✝✆✝✞ þ✠✟✯þ✝✄ ✡✧þ✡þ☛✆☞✄ ý✡þ✠✌✝ ✍ ✂ ✄✎☎✝✆✢ÿ✑✏ ☎✝✂ ✄✘þ✒✍ ✍ ✓✔✆ þ✝✓✔✕✖✂☞✟✁ ✄ ✂✗ ✂✎✄ ý✯þ ✘☛✙✝✚ ✛☛✜✣✢ ✤✝✥ ✦✎✜ ✧ ★✪✩✑✫✗✬✖✭✑✩✑✮✰✯✗✱✳✲✴✱✳✮✰✵✷✶✹✸✺✫✻✯✗✬ ✼✳✱✳✲✾✽✰✱✳✫✗✬✖✯❀✿❂❁❄❃✴✸✺✼✰❅❇❆❀❈☞❉ ❊❇❋❍●✖● ■❀❏✝❑✔▲✺▼✝◆✒▲✺❖❍▲✁P✝P✝■☛❑☛▲✴◗ ❏✗■✑❖❍■✒▼✝●✔◗ ❘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 1 1 1 1 1 1 1 1 1 1
❙✪❚✑❯✗❱✖❲✑❚✑❳✰❨✗❩✳❬✴❩✳❳✰❭✷❪✹❫✺❯✻❨✗❱ ❴✳❩✳❬✾❵✰❩✳❯✗❱✖❨❀❛❂❜❄❝✴❫✺❴✰❞❇❡❀❢❤❣ ✐❦❥❀❧✁♠✻♥☛♦✔♣ q✑r✳s✁t ✉✝✈❀✇ q①♥✔r✒②☛t ♣✖③✑④✔⑤✒q❀④☛⑥✠❧❀✉✗q✒r✁④✔⑤✺② ❧✒⑦1 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 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 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 1
⑧✪⑨✑⑩✗❶ ❷✺⑨✰❸✰❹✗❺✰❻✴❺✳❸✰❼❾❽➀❿✺⑩✗❹✗❶✖➁✳❺✳❻✾➂✳❺✰⑩✗❶ ❹➄➃❂➅➇➆✾❿✺➁✰➈ ➉❀➊❄➋ ➌❦➍❀➎✁➏✻➐☛➑✔➒ ➓✑➔✳→✁➣ ↔✝↕❀➙ ➓①➐✔➔✒➛☛➣ ➒✖➜✑➝✔➞✒➓❀➝☛➟✠➎❀↔✗➓✒➔✁➝✔➞✺➝✝➎➄➙ ➑✒➏✠↔ ➠✰➡✗➢✑➤✑➥✺➡✻➦✗➧ ➥✺➨➩➢✰➫➯➭✪➢✑➡✗➧✖➲✑➢✑➳✰➦✗➵✳➸✴➵✳➳✰➺✷➻✹➥✺➡✻➦✗➧ ➼✳➵✳➸ ➠✰➵✳➡✻➧ ➦➄➽➚➾❄➪✾➥✺➼✳➶ ➹❦➘❀➴✁➷✒➬✎➮ ➱✳➷❐✃ ➱✔❒ ❮✁❰☛Ï✖➬✾✃ ➱✳Ð ÑÓÒ✣Ô✁Õ Ô➄Ö✝Õ ×✠Ø❀Ù Ù✒Ú✁Û☛Ü ×✔Õ ×✠Ý☛Þ✑Ü Ý✒ß➀Ù Ô➄à✔á☛Õ✝â✑ã✰ä❍Ú❐å Õ ×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 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 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 1 1 1 1 1 1 1 1
æ✺çéè ê➩ë✰ì✑ç✪ç✗í✾îðï❐ñ✑ò✻ì✑óéè ê✻î✺ô❾õ ö✳ë✰ô✾÷ùø❀ú✳ì✑ô✾î ô✾è ê✠ç✗ö✳ë✰ú✳îðû➯ü❤ý1 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 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
þ ÿ ✁✄✂✆☎✞✝✠✟ ÿ✆✡☞☛ ✁✍✌✆✎✑✏ ✒✓☎✆✔✕✁✗✖✘☎✆✙✗✚✛✌ ✡ ✏ ✒ ☛☞☛✢✜ ☛ ✣ ✒✓✁✗✒✓✤✆✁✗✒ ✣ ✥ ✂ ✡☞✜ ✁✦✝✠✧★✖✩✒✓✤✫✪✬✧★✌ ✣ ✒ ☛ ✭✯✮✱✰✦✲✳✰✦✴ ✵✷✶ ✸ ✹✺✵✼✻✽✸ ✾✷✲☞✾✽✿✆❀✼✾❁✴✽✸ ✹❂✾✷✲✺✻ ✵✦✶✺✵✷✲❂❃✕❄✺✰✷✴✳✻✽✸ ❅✺✵✷✶✼❆✺✵❁✴✽✸ ✻ ❇✕❅✽❀✽✰✦❅✽❈ ❉✬❊✞❋✼●✓❍✺■❁❏✼●✕❑✼❏✦❏✼▲☞❑✫▲✺●✷▼◆■✽❖✕❍❂❋✼●✷❍✼P❂◗ ❘❚❙ ▼ ▲❁❯❂●✼❑❁❍❂❋✆■✽❖✆❱❲❋✦❙ ❍❂❋❳❙ ▲☞❑✕❨❂❑✼❩✽❙ ▼ ❬ ❍❂❋✼●✷❍✼P☞■✽❖❭❑✫▲❂❪❁❘✼▲✺●❁▼✗■✽❖✫▼✺❋✼●❳❘✦❙ ▼ ▲✓❙ ❫❭▼✺❋✽●❵❴◆●✼▲❂▲✺❑✽❛❂● ❜✬❝✺❞✼❡✽❢ ❣✳❤✕✐❂❥✼❦✷✐✽❧✆✐✳♠❁♥✼❦❁♦☞❞❁❡ ❦✩♣ q r❂s✼t✽✉✺✈✆✇✞①✼②✽③✆④ ⑤❁⑥ ⑦✬⑧✗⑨✗⑩✷❶✺❶ ❷✷⑨✳⑩✼❷❁❸✺❹✆❺◆❻✼❼✺❼✺❽✼❾❂❻ ❿ ❼☞❽❁➀❂➀✳❻✦➁❂➂ ❻✦➃✩❿ ➄❂➄➅❿ ❼ ❽❵➆ ❻❁❾✽❽✷➆✼➀✳❷❁➃✼❻✦➇ ➈✱❷❁➉✺➃C M M C M C M ( ) ( ) ( )
1 2 1 2
⊕ = ⊕
( )
E C M ⊕ E
➊★➋❳➌✓➍✆➎✬➏➑➐ ➒✕➐ ➓✄➔✘➌✓➓✗➋✩→✆➣ ↔Make each number of digits {0..8} divisible by 9
↕Example: 823 is to be sent
➙Detects all single-digit errors: 7235, 8335, 8255, 8237
➠Detects several multiple-digit errors: 8765, 7346
➡Does not detect some errors: 7335, 8775, …
➢Detection is efficient
➤✫➥★➦✆➧ ➨✳➦✑➩➭➫✓➯✩➲✆➳✆➯✩➵✆➳✆➦✱➥➸➤➻➺✩➫✓➦✆➼ ➽➚➾➶➪✦➹✳➘✼➴✳➪✕➴❂➷✽➪❵➬◆➪✼➮✺➮✺➱✼✃❂➪❳❐❚❒ ➴ ➮❭➱❂➮ ❮✬❰✦Ï✷Ð✼Ñ Ï❁Ò✺Ï✦Ó✺Ô☞Ô✺Õ✽Ï❵Ö◆Ï❁Ò✺Ò✺×✽Ø✽Ï✆×✽Ò☞×✕Ð❂Ù✦Ú Û✷Ó✳Ù❁Ö✫Ü ×✦Ú❂Ý◆Ü Ô✺Õ✆Þ ß✞à á â❲ã✺Ù✽Ï✼ä❂ä✷Ü ã✼Ü Ï✦Ó✺Ô Ò å✬æ✞ç✼è✓é❁ê ë❚ì í✳î❭ï❚ð❚ï➻ì î✆ñ✳ò❁ó☞ô✽õ✽í è✷ö✕÷❂î øúù❲û✼ü✷ý ü✫þ✷ÿ ✂✁☎✄ ✆✞✝✠✟☛✡✌☞✂✍✎☞✑✏✠✡✂✒✓✡✕✔ ✖☛✝ ✗✘✔✞✙✚✗✎✛ ✜✕✒✓✗✘✢✣✄ ✖✕✛✠✗☛✤✦✥✧✡✕✏✧✔ ✡✧✡✩★✘✪ ✫✭✬✯✮✧✰✲✱✠✳ ✴✕✵✓✶☛✷✣✸ ✱✚✱ ✰✕✹✲✺✧✳ ✴✧✷☎✰✻✸ ✶ ✸ ✵✽✼✧✱✠✮☛✰✎✳✽✾✿✼✘✳✚✹✂❀☛✱✚✮☛✰✩✷☎✰✧✶✠✶✚✴☛❁✠✰✲✺✠✼✎❂ ❂ ✼✧✾✿✰✕✹✑❃☛❄✲✱✚✮☛✰✩❅✚✼☛✰✧✺✠✺✕✸ ❅✧✸ ✰✂✵✚✱ ✶✞✼☛✺✌❆ ❇ ❈✂❉s D s D s D s
K K K K
( ) = + + +
− − − − 1 1 2 2
❊c D s D D g D
L
( ) ( ) ( ) = R em ainder s D D c D
L
( ) ( ) +
1 2 1
,s ,s , ,s s
k k
❋− −
1 1 1 1 1 1 0 0 1 1 1 0 + 1 0 1 0 X 1 1 1 1 1 0 1 0 0 1 0 1 1 1 0 0 1 1 1 1 1 0 0 1 1 1 1 0 1 0 1 1 1 1 0 0 0 0
0101110 : ) ( 1 ) ( 1 ) ( 1 ) ( 0101
2 2 3 4 2 3 4 2 4 5 2 3 5 2 3 3 5 3 2 3 2 ♣✠q r s✽tD D D c D D D D D D D D D D D D D D D D D D D D D s D D D g D D s M + = + + + + + + + + + + + + = + + = + = =
<− remainder
✉✭✈✕✇ ①✓②✧③✘④❯⑤✓⑥✘⑦✘② ⑧⑩⑨✽❶✓❷✕❸ ❹✘❺✠❻✦❼✎❶✧❸ ❹✣❻✕❽✚❽ ❼✘❽❯❾✠❼✎❸ ❹✕❶✓❼✘❿✣➀ ❷✎❸ ➁✭➂❯➃ ➃✚➄✕➅ ➆✚➇✕➃ ➈✩➉✂➅ ➊✽➈✕➋✚➋ ➌✘➋ ➄❯➍✘➋ ➈✌➎✘➈✘➊ ➈✕➏✠➊ ➈✕➎ ➐❤➑✧➒❯➓✕➔ →✂➣☎↔ ↕✣➙➛↔ ➜✧↔ ↕✘↔ ➝✂➞ ➟✑➝☛➠✻➡☎➢ ➤✯➥✕➦ ➦✚➧✎➨✓➨ ➩✘➨ ➫✣➭☎➯ ➲✚➳✦➩✘➵✎➵✩➸✚➺✧➻✞➼✧➧✕➨☎➩☛➽✣➩✕➸✓➧✧➫ ➥✧➨ ➧✩➵✧➧✕➲ ➧✕➾✚➲✓➧✕➵ ➚➶➪ ➹❯➘✕➴ ➷✂➬✽➮ ➱✦✃✂➮ ❐✧➮ ➱✘➮ ❒✎❮ ❰✩❒✧Ï✣Ð✲Ñ✧Ò✠➮ Ó✣➮ Ô✧➮ ❐✓❰✩Ñ✠Õ✎❮ Ï✘Ö✚Õ✘Ó✣➮ Ð✕❮✠Õ☛×✲✃✧❰✘Ø✘Ò ❰✘❰✑Ù✲Ú✠Û☛Ü Ý✓Þ✘ß Ü ß Ü✘Ú Ü Ý Ú à✞á✕â â☛Ú✓ã Þ✩ä✎å Ú à❯Ü✎æ✓æ Þ æ à å ç✣è Ü✧à✚à✚á✧é✠Ü✧à Þ☛ê â Ü✧à✚à✣Ú✚Û☛á ç✦ë✕ì í✂î ï ð ñ➶ò➛ó✘ô ó✎õ✚ô ö✞÷✕ø ø✧ù✘ú☛û ö✠ô ö✞ü☛ý✩ø ó✧ö✚ö✣ô✚þ✧÷✘ÿ✁✄✂ ☎✝✆✟✞✝✠ ✆✝✆✄✡☞☛✍✌✟✎ ✏✒✑ ✓✕✔✒✖ ✗ ✘ ✙✛✚✢✜✄✣✄✤✥✚✍✦✢✧ ✤✥★✩✜✛✪✬✫✮✭✯✫D D D CRC D D D CRC CCITT
16 15 2 16 12 51 32 1 + + + − + + + − D D D CRC Ethernet, FDDI,...
22 16 121 + + + D D D
4 2+ + + D D D
32 26 23+ + + D D D
7 5 8+ + + D D
11 10+ + + 16 −
✰✲✱✛✳✢✴✶✵✷✱✸✳✍✹✻✺✽✼✿✾✄❀ ✹✥✼✿✹✥❁✄❂✢✱✸❂✢❃ ❄✛❁❅❄✄❆❈❇✮❉❊❇C2 G3 C3 C1 G2 C0 G1 G0 Input
❋❊●■❍❑❏✸▲✛▼❖◆❊P✥P✥▼✶◗✕❘✷❙✛❚ ❙✛❯✩❙✛▲ ❱✻❲✕❳✝❨✽❩✝❨✝❬☞❭✁❪✝❫❵❴✝❛❜❫✁❝❞❴❢❡❞❡ ❨❣❝❞❭☞❤ ❫❞✐✄❝❵❴❢❥✝❨❢❬✍❦❢❡ ❨✄❧♠❬❢❤ ❫❞✐✁❦✸❬❢❤ ♥✸❤ ♦ ❦❢❡ ❦✝♣✝♣✝❡ ❴☞❦✝❝♠❳❣q rts✟✉✒✈①✇♠②❞③✄②❞④❢⑤⑥③✽⑤✍⑦ ⑧✒⑨ ⑩✁⑧✒⑨ ❶❵❷❢❸ ❹✛②♠⑩❞❸☞⑨ ❶❞❺✽⑨ ❶❞②♠⑩ ③✝❷✝❻✄④☞❼✛⑩❞❽✝③✛❾ ❿✕➀ ➁ ➂➃✇❞②❞③❣❻✶⑨ ❶ ✉✒➄❣✉➆➅ ➇✻➈❣➉✝➉✟➊✟➋ ➌➎➍❣➏ ➍❢➐⑥➍✟➑✛➒ ➓✁➔✁➓☞→♠➉✟➣❢➒ ➔❣➏☞➣❞➔♠➓❞➉➆↔♠↕➃➙✝➉✟➛ ➉✥➜❞➙✝➉✽➑❞➝✝➐✁➞✝➉✟➛⑥➍☞➟✄➊✝➔☞➜❵➔ ➓❞➠❢➐✁➞☞➍❣➏ ➓✍➔✟➑♠➊✄➜❞➙✝➉➡➑❞➝✝➐✍➞✝➉✟➛✢➍☞➟✛➛ ➉✟➊✟➝✝➑♠➊❢➔❢➑❞➜✢➓❞➠❢➐✍➞✝➍❣➏ ➓✥➒ ➓✁➔✄→❞➍✝↕✕➉✟➛⑥➍☞➟ ➢✒➤ ➥✻➦✕➧☞➨☞➩✥➨❵➫❢➭❢➯✝➲✁➳✝➵ ➯✥➵ ➫✟➸❢➧♠➲♠➺✢➺ ➫✽➸❢➧☞➵ ➲♠➺✢➯✟➵❞➵ ➫❢➵ ➲❢➻♠➼➃➩✒➽ ➨☞➩➡➽ ➲✸➺❞➩✝➯✥➺ ➾✝➚✟➽ ➨❵➳✟➪ ➶ ➽ ➹♠➭✄➫☞➘✸➯✟➵❞➵ ➫❢➵✍➼➎➯✄➘♠➳✝➨❵➯✒➴ ➷➮➬ ➱ ✃⑥❐✟➬ ❒ ❮ ❰ Ï ➱ Ð Ñ Ò Ó Ð Ò Ô Õ Ï ✃♠❒ Ö × Ò ❰ Ø Ù Ð ❰ Ú ÛÝÜ✸Þ✄Þ✄ß✥àâá✷ã✶ä å✸æ✲ç❊ß✥è✄ä é✍æ✢ß✥ê✍é ë❅ì✟í❢î✍ï☞ð♠ñ ò❢ó✍ô✥õ✒ö ÷♠ø☞ù ú➡û❵ü✝÷➆ý ü❢þ ÿ✁ ö ü✝÷✄✂✆☎✞✝✠✟☛✡✌☞ ✍✏✎✆✑✏✝☛✒ gL g1 g0 m j L − m j−1 m j State Inputx m g
j j i i i L
=
− =
∑
✓✕✔✞✖✞✗✘✔✚✙ ✛✞✜✄✢ ✔✚✖✞✣✤✙ ✓✕✔✚✥✧✦✩★ ✪✬✫✮✭✏✯✆✰✏✱✞✲ ✳✘✴✤✳✏✱✠✵ ✶☛✴✸✷✺✹✆✻✚✼✾✽ ✿✮❀ ❁ ❂✘❂✠❃✸❄❅✿☛❆✮❇ ❂ ❈❊❉✘❋✆●✠❍✆❋✏●✞■ ❏✘❑✤❏✏●✠▲ ▼☛❑✸◆✺❖✆P✩◗✏❘ ❙✾❚ ❯❲❱✘❱✠❳✸❨❅❙✆❩✮❬ ❱ ❭❊❪✘❫✆❴✠❵✆❫✏❴✞❛ ❜✤❝✠❞✸❡✄❵✆❫✆❴ ❢❤❣✌✐☛❥✞❴✠❦☛❢✩❝✠❞❤❧✠♠❲❞✮♥ ❫✆❴✆❛ ❞❤❧ ♦ ❦☛❢❤♣ ❢rqts✈✉ ✇✤①✠②✆③✤④✸⑤ ⑥✠⑦✌⑧ ⑨✏⑩✏❶✆⑥✄❷✠❸✸❹❅❺✆❻✮❼ ❽ ⑨✏❾✤❿✁➀❲➁ ➂❅➃✚➄❅➅ ➆❅➇➉➈☛➊✠➋✆➌ ➍ ➎❊➏➑➐☛➒✩➓✠➔❤→✠➣❲➔✮↔ ↕✆➙✆➛ ➔❤→❅➓✠➜✸→✤➝☛➒r➓❲➔✸➞✘➟✆↕✆➙ ➒❤➠✌➝✆➡✚↕✠➢✸➛ →✠➤✚➥✤➦✆➧✮➨ ➩✆➫✘➭ ➯❤➲❤➨ ➦✆➫ ➯❤➭ ➦x m g
j j i i i L
=
− =
∑
00 11 11 00 10 01 01 10 Output Current state Next state 00 = a 01 = b 10 = c 11 = d a = 00 b = 01 c = 10 d = 11
( )
x m m m m m
j j j j j j
= ⊕ ⊕ ⊕
− − − 2 1 2 On 1 On 0 1101 becomes 11 01 01 00
üþý✩ÿ✁✄✂✆☎ ✝✟✞ ✠✡✄✝✟☛☞✄✌ ✍✟✎✏☎ ✄✝✟✑✁✌ ✠✒✟✂➪ý ✓✕✔✗✖ ✘✚✙✜✛ ✢✟✖ ✣✥✤ ✦✧✢✩★ ★ ✦✜★ ✪✚✫✬★ ✢✭✙✮★ ✢✬✪ ✢✬✤ ✯✱✰ ✲✕✳✵✴ ✴ ✶✜✴ ✷✚✸✬✴ ✹✁✺ ✶✬✴ ✴ ✹✩✺ ✻ ✹✬✼✁✽✮✾✏✻ ✿✮✹✁❀❂❁ ✻ ✹✜✴ ✽✵❁ ✸✜❃ ❄✮✶✜✴ ❁ ✻ ✿✜❅✥❆ ❇❉❈❋❊✮●☞❍✬■ ❏✮❑✜▲ ▼ ◆ ❊✩❖✡P✱●✮●✬◗✮❘❙❍✧❘01 11
00 11 00 00 11 11 10 01 11 00 10 01 01 10 2 3 3 2 5 2 3 4 4 4 1 1
11 Input:
1 1 1 1 1 1 1 1 00 = a 01 = b 10 = c 11 = d a = 00 b = 01 c = 10 d = 11 Scheme
✻✩✼✫✽ ✾✮✿ ❀☎✽✱❁☎❂✳✿ ❃✶❄ ❅✎❆✎❁☎✿ ❀☎✼✺❇❉❈❋❊✡❆✡●✎❀☞❍ ■3 3 2 2 3 1 1 2 1 2 2 3 3 2 1 3 3 3 1 3 3 2 2 2 3 4 3 4 2 4 4 5 5 2 4 2 5 2
11 01 11 00 01 10 00 11 11 10 11 00 11 1 01 00 1 01 1 10 1 01 11 11 1 01 1 10 11 00
00 11 11 00 10 01 01 10 00 = a 01 = b 10 = c 11 = d a = 00 b = 01 c = 10 d = 11
Output:
Corrected:
Input:
❏▲❑◆▼ ❖✆P ◗✺▼ ❘❚❙❱❯✱❯◆❘✫❲✡❲❨❳✳P ❩◆❬✺❲❨❭◆❩◆❪▲❫◆❴✆❵✺❖✆❵◆❯◆❵◆▼ ❲ ❛❝❜✖❞ ❡✣❡✫❢ ❣✐❤✁❡✐❥✎❦✝❧✳♠ ♥ ♦✝♣✓❥✣q r s✣t✈✉ ❦✇♥ ♦✓❢✁① ❢ ❦✣① ❤✁❦✇♥ ♦✓❢ r ❥✣♥ ♦✓②✇♠ ❡✫③✒♥ ❞ ❡ t r ④✖t☞⑤ ❞ ❦ s✐⑥✖⑦✓s ❥✁❢ r ❥✝❜ s ❞ ❡ ⑥ ③✒♥ ❞ ❡✺❦✣❞✡⑧✒❡ ⑥ ♥ ⑨✐⑧✆⑩✖❡✣②✖❶✣❷✇① ♦✟❡✣❢✝❶ ③✒♥ ❞ ❡❸♠ ❡✐❥✓❥✣❶✁❡✣❢ ⑦✝❹ t r ⑦✝t✈❺ ③✒♥ ❢ ⑦ ❜✐❡ ⑥✳r ❡✣②✖❶✁❥✁③✒♥ ❢ ⑦ ❜✐❡ ⑥ ❷✇① ♦✟❡✣❢✝❶✐❻☎❛❝❼❽❡✖❢ ⑦✁t ❾ ❡✺❥✁❢ s ❞✟❢✆③✒♥ ❢✓❜✳❿✇➀ ➁✝➂✣➃✖➄✝➂✐➅✓➆✺➇ ➈ ➉✝➊✟➋✣➌✝➍◆➎✇➈ ➉✱➏✁➐✐➎✖➇ ➇ ➑✦➉✓➒✁➑✦➓ ➔✺→✐➣ ↔✝↕ ➙✣➣ ➛✩➜☞➝✝➝✁➛✣➞✓➞➠➟✐➡ ➢✝↔✟➢✐➝✁➢✣➣ ➤▲➥◆➦ ➧✆➨ ➩✺➦ ➫❚➭❱➯✱➯◆➫✫➲✡➲❨➳✮➵◆➸◆➧✆➺✡➵◆➦➠➻✖➤▲➭❱➳✮➼ ➽◆➺✆➵✺➧✆➵◆➯◆➵◆➦ ➲ ➾➪➚✫➶☎➹➴➘✐➷ ➬✐➮ ➬✣➱✓➬✇✃ ❐✣➱✟➬✝➬✣➷✓❒✦❮ ❰✟Ï✝➮ Ð✣Ñ✎➮✓➷ Ï✣❰✓Ñ✝Ò✱❮ Ñ✓Ñ✣❮ ➬✖❰✟Ñ✡Ó✐➷ ➬✣ÒÔ❒✦❮ Ó✝Ó✁Ð✖➷ Ð✇❰✓➮ Ñ✁➮ Ï✐➮✝❮ ➬✖❰✟Ñ✫❮ ❰✡➬✣➷✓❒✐Ð✖➷✡➮ ➬✺Ò✱❮ ❰✐❮ Ò✱❮ Õ✓Ð✖Ö✓Ï✝×✟➬✦❮ ❒✳➱✟➬✇✃ ✃ ❮ Ñ✣❮ ➬✖❰✟Ñ Ø➪Ù Ú✐Û❸Ü❝Ý✁Þ✖ß✝ß✁à✇á❝â✁Þ✖ã✟ä✝å ä✝å æ✐ß✣å ß✁ç✫è✫é☎ê➴ë✐ì í✣î í✣ï✟í✇ð ñ ò➪ó ô✖õ❸ö✦÷✖ø✁ù✖ú✐ûýü☎þ✁þ✁ÿ✁✂☎✄✝✆✟✞✡✠☞☛ ✌☞✍ ✌✁✎✏✌✒✑ ✓ ✔✖✕ ✗✙✘✛✚ ✜✣✢✥✤✁✦ ✧✙★✪✩✂✫✭✬✂✧✙✮✙✯✟✰✝✱✟✲✡✳☞✴ ✵☞✶ ✵✁✷✏✵✒✸ ✹ ✺✼✻✛✽✭✾✒✿ ❀✭❁☞❂✙❂✁❃ ❄✁❃ ❁✁❅✙❆✁❇❈❂✙❉❊❃ ❋☞❇❈●✁❃ ❍❈■✁❏ ❁❑❇❈▲✥❁✁❄✙❁✥❅✙❆✂❋✏❉✒❏ ❃ ▼✭❁✁▲S
−
S
1
1= ≡
S m T S 1 ) 1 ( 1 1
1 2 1= ± = ≡
∑
= = m i i m i im S S m S S 1 ) 1 )( 1 ( 1 1
1 _ 1 _− = − + = ≡
∑
= = m i i m i im S S m S S
➌➎➍➐➏➒➑➔➓✷→↔➣➙↕ ➛➂➜❡➝⑥➓➂→➂➛➂➞☞➟ ➠❡➡➤➢ ➥ ➦✁➥✟➧ ➨✟➩✻➢ ➫✖➩✁➭➂➧ ➥ ➢✻➯ ➲❃➧ ➳☞➢ ➫✖➵✟➸ ➫✖➩✟➯ ➫✏➺ ➨✝➻☎➼ ➽ ➾⑥➦✟➩✁➭➂➧ ➥ ➢✫➩✁➫✁➚✟➦✁➥✟➧ ➨✖➩✳➺ ➨✖➻✫➼ ➪✦➾ ➶❡➹➤➘✖➴✖➷✻➬ ➮ ➱✁➮✟✃ ❐✖➷✁➬☎➮✁❒ ➱✁➷✟➬ ❮✳✃ ➮✳➬✁✃ ❮☎❰✖Ï ➮ ➱✟➷ ➴✟❐✖❰✁➬✁Ï Ð✔Ñ✁➮ ➘✟➴❃✃ ❒☎➬✁✃ Ò✝➷ ➱✝Ï ➬✫➱✁Ó✔Ó➂Ï ✃ ➷ ➴✖➱✖❒ Ï Ð Ô➎Õ➐Ö➒×➔Ø✷Ù↔Ú➙Û Ü➂Ý❡Þ⑥Ø➂Ù➂Ü➂ß☞à á❶â✦ã✙ä å✔æ ã✖ç å✔ä✎è é✟å✷ê✔ë è✳ì è✁ä å✖í✖î➤ã✖ï✫í☞ì è í✁è✟ë ã✟ð✻ñ✦å✏ò✁ì å➂ë è ì✻æ é✔ë ó☞ì å✖ô✟ò å✖ð✖æ å õ✰ö✝÷✳ø ù✟ú✷û ú✝ü ú❃ý þ ú✖ÿ✁✔ý ø✄✂ ø✁û ú✆☎✞✝ ý ✂✠✟☛✡ ☞✍✌✠✎ ✏ ✑✒✏✞✓ ☞✞✔✖✕✘✗✙✓ ✏ ✚✜✛ ✢✤✣ ✏ ☞✍✌✠✥✧✦ ★ ✩✆✪✆✫✖✬ ✭✆✮✙✪✞✯✤✰✆✱✠✲✍✳ ✪ ✴✶✵✞✷✠✵✹✸ ✺✍✷ ✻✆✼ ✽✿✾❀✺❂❁✞✺✆✽ ❃✁❄✞❅✠❆ ❇✄❈ ✷ ✺✆❉ ✽✄❊ ❅ ❋) 1 ( ) (
_ _ _+ − + + =
=
+ + =
+ + = C D C C C B C A C D C B A C X D C B A X
τ−ε τ
✆✞✝✠✟☛✡✌☞✎✍ ✏✒✑☛✆✔✓✖✕ ✕ ✍ ✗✘✍ ✓✖✙✛✚✢✜✂✏✒✜✂✣✤✏✒✍ ✓✤✙(Tanenbaum)
✥✞✦✠✧☛★✪✩✫✥✞✬✮✭✫✯✖✰ ✰ ✱ ✲✘✱✳✯✤✴✛✵✷✶✂✸✒✶✂✭✤✸✒✱ ✯✤✴(Tanenbaum)
✹✻✺✎✼✫✽✖✾ ✿✤❀❁✺✎❂✤❃✒✿✖❄✘❅✠❆☛❇✪❈❊❉✂❃✒❋✖●✒❋✤❍✤❋✤■ ❄ ❏❁❑▼▲✫◆✁❖◗P✒❘▼❙❯❚❱❖❳❲✳❙✖❨❩❙❳❙❭❬✘❪❩❚❳❖❱❪✒❫◗❴❱❵◗❛❱❛❱❜❞❝❢❡✁❵❞❣✳❤❱✐ ❤❱✐ ❥❳❛◗✐ ❛✁❦✖❧❯♠❢♥ ♦❳♣ q◗r q◗s✳q☎t ✉✤✈ ✇②① ❧④③◗⑤ ① ❧✢⑥◗⑦❱⑧✖♥ ① ❧❯♠②⑨ s ⑥◗⑦ ✉❱⑩ ⑥ ♣ ❶✂r❩⑩❱❶❯s❱⑩ ⑥❞⑦❱⑦ ❶❭t ❷ ⑥❞❸ ♣❱t ❹❳❺✻❻❳❼❱r ⑥ ✉ ❸ ⑦❩❽ t ❶✖✉✁r ⑥ r ❸ q ⑦ s ⑥❞⑦❱⑦ q❳r✘❼❩✉❩❶ ❸ r ⑥ t t ❾✛❿❭➀◗➁❱➂❞➃❳➄➅➀◗➆✁➆✁➇◗➈❩➈✤➉✂➊②➋④➌❳➍ ➎❳➏ ➎◗➐✳➎☎➑ ➒➔➓❞➑ ➑ ➎❳→✔➓✫➒◗➣ ↔❩↕❞➑ ➙✂➛✁➒❩➙❞➍✒➜❱➛◗➑ ➑ ➐✁➝❳➓◗↔❱↔❩➙❭➑❱➍ ➓❳➏ ➙◗➞✻➟◗➛✁➏➔➐✳➓❞↔❱↔✳➎❳➏➠➒❳➝❱➓◗➍ ➙✂➏❩➝❳➙❯➐✁➝❳➓◗↔❱↔✳➙✻➑❩➜✁➓☎➣ ➍❱➑ ➡✖➢ ➣ ↔✒➜✁➓◗➐❩➏❱➤ ➥✁➦❞➧❱➨❩➩❱➫ ➭✷➯ ➲➔➳❱➵❱➸ ➺☎➻✘➳❞➼❱➲❩➺☎➽ ➾❩➺❞➚❞➪ ➶❁➹✘➘ ➴❩➷✤➬✁➮❱➱☎✃ ➱✖❐◗✃ ➱✂❒ ➬✳❐◗❮◗❰ Ï❩Ð✤➬✳Ñ❳✃✁Ï✳➴✁Ò❢Ó❳✃ ➷❳➬ ➷◗Ô❩➷☎➘ ➴❳Õ Õ Õ