User manual

ManualsBrandsLECROY ManualsTest & Measurement Accessoriestrigger and decoder extension Compatible with WaveSurfer® oscilloscopes.

Operator's Manual

919586 RevA

Table 3-3.† For D.x.7, the Primary (D.x.P7) or Alternate (D.x.A7) encoding must be selected in order to avoid a run of five

consecutive 0s or 1s when combined with the preceding 5b/6b code. Sequences of five identical bits are used in comma

codes for synchronization issues. D.x.A7 is only used for x=17, x=18, and x=20 when RD=−1 and for x=11, x=13, and x=14

when RD=+1. With x=23, x=27, x=29, and x=30, the same code forms the control codes K.x.7. Any other x.A7 code can't

be used as it would result in chances for misaligned comma sequences.

‡ The alternate encoding for the K.x.y codes with disparity 0 allow for K.28.1, K.28.5, and K.28.7 to be "comma" codes

that contain a bit sequence that can't be found elsewhere in the data stream.

CONTROL SYMBOLS

Input

RD = -1

RD = +1

HGF EDCBA

abcdei fghj

K.28.0

000 11100

001111 0100

110000 1011

K.28.1 †

001 11100

001111 1001

110000 0110

K.28.2

010 11100

001111 0101

110000 1010

K.28.3

011 11100

001111 0011

110000 1100

K.28.4

100 11100

001111 0010

110000 1101

K.28.5 †

101 11100

001111 1010

110000 0101

K.28.6

110 11100

001111 0110

110000 1001

K.28.7 ‡

111 11100

001111 1000

110000 0111

K.23.7

111 10111

111010 1000

000101 0111

K.27.7

111 11011

110110 1000

001001 0111

K.29.7

111 11101

101110 1000

010001 0111

K.30.7

111 11110

011110 1000

100001 0111

Table 3-4.† Within the control symbols, K.28.1, K.28.5, and K.28.7 are "comma symbols." Comma symbols are used for

synchronization (finding the alignment of the 8b/10b codes within a bit-stream). If K.28.7 is not used, the unique comma

sequences 0011111 or 1100000 cannot be found at any bit position within any combination of normal codes.

‡ If K.28.7 is allowed in the actual coding, a more complex definition of the synchronization pattern than suggested by †

needs to be used, as a combination of K.28.7 with several other codes forms a false misaligned comma symbol

overlapping the two codes. A sequence of multiple K.28.7 codes is not allowable in any case, as this would result in

undetectable misaligned comma symbols.

K.28.7 is the only comma symbol that cannot be the result of a single bit error in the data stream.

SOURCE

Peter A. Franaszek, Albert X. Widmer, et al. "Byte oriented DC balanced (0,4) 8B/10B partitioned block

transmission code." US Patent 4486739. December 4, 1984.