Difference between revisions of "Non Return to Zero"
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| − | '''Non Return to Zero''' (usually given as the acronym, '''NRZ''') is an [[encoding]] technique which is commonly used on [[magnetic storage]]. | + | '''Non Return to Zero''' (usually given as the acronym, '''NRZ''') is an [[encoding]] technique which is commonly used on [[magnetic storage]] and [[serial line]]s. |
In NRZ, whether a particular [[bit]] is '0' or '1' is indicated by the [[signal]] level during each [[clock]] time; in other words, there is no 'rest' state between bits. | In NRZ, whether a particular [[bit]] is '0' or '1' is indicated by the [[signal]] level during each [[clock]] time; in other words, there is no 'rest' state between bits. | ||
| − | The disadvantage of NRZ is that a long strings of either value do ''not'' cause any level transitions (hence the name), so a separate clock is always needed, because it cannot be self-clocking (unless used with either [[bit stuffing]] or [[run-length limited coding]], to limit the maximum number of transition-less bit times). | + | The disadvantage of NRZ is that a long strings of either value do ''not'' cause any level transitions (hence the name), so a separate clock is always needed, because it cannot be self-clocking (unless used with a periodic explicit clock, or with either [[bit stuffing]] or [[run-length limited coding]], to limit the maximum number of transition-less bit times). |
==See also== | ==See also== | ||
Revision as of 12:13, 10 May 2020
Non Return to Zero (usually given as the acronym, NRZ) is an encoding technique which is commonly used on magnetic storage and serial lines.
In NRZ, whether a particular bit is '0' or '1' is indicated by the signal level during each clock time; in other words, there is no 'rest' state between bits.
The disadvantage of NRZ is that a long strings of either value do not cause any level transitions (hence the name), so a separate clock is always needed, because it cannot be self-clocking (unless used with a periodic explicit clock, or with either bit stuffing or run-length limited coding, to limit the maximum number of transition-less bit times).
