256b/257b Transcoding for 100 Gb/s Backplane and Copper Cable

8

IBM

Block Type Field

According to clause 82.2.3.1 the LSB of the block type field (BTF) represented as a

hexadecimal value is the first transmitted bit. For example, the block type field 0x1E is

sent from left to right as 01111000.

BTFj(8)=BTFj<7:0> where BTFj<0> is the first transmitted bit. We represent BTFj(8) as

the concatenation of the first nibble Fj(4)=BTFj<3:0> and the second nibble

Sj(4)=BTFj<7:4>. For example, for BTFj(8)=0x1E, we obtain Fj(4)=0xE sent from left to

right as 0111 and Sj(4)=0x1 sent from left to right as 1000.

CBj(56)

0x1E

BTFj(8)

CBj(56)

0xE 0x1

Fj(4) Sj(4)

CBj(56)

Fj(4) Sj(4)

or

or