Arria® V Device Handbook: Volume 2: Transceivers

ID 683573
Date 5/29/2020
Document Table of Contents 8B/10B Encoder in Single-Width Mode

In single-width mode, the 8B/10B encoder generates 10-bit code groups from 8-bit data and 1-bit control identifier with proper disparity according to the PCS reference diagram in Clause 36 of the IEEE 802.3 specification. The 10-bit code groups are generated as valid data code-groups (/Dx.y/) or special control code-groups (/Kx.y/), depending on the 1-bit control identifier.

Figure 25. 8B/10B Encoder Diagram in Single-Width Mode

The IEEE 802.3 specification identifies only 12 sets of 8-bit characters as /Kx.y/. If other sets of 8-bit characters are set to encode as special control code-groups, the 8B/10B encoder may encode the output 10-bit code as an invalid code (it does not map to a valid /Dx.y/ or /Kx.y/ code), or unintended valid /Dx.y/ code, depending on the value entered.