Special Characters - Xilinx 7 Series User Manual

•
•
•
Figure 4-34
data with disparity error (B), an out-of-table character (C), and an out-of-table character with
disparity error (D).
X-Ref Target - Figure 4-34

Special Characters

8B/10B decoding includes special characters (K characters) that are often used for control functions.
When RXDATA is a K character, the decoder drives RXCHARISK High.
If DEC_PCOMMA_DETECT is set to TRUE, the decoder drives the corresponding
RXCHARISCOMMA High whenever RXDATA is a positive 8B/10B comma. If
DEC_MCOMMA_DETECT is TRUE, the decoder drives the corresponding RXCHARISCOMMA
bit High whenever RXDATA is a negative 8B/10B comma.
7 Series FPGAs GTP Transceivers User Guide
UG482 (v1.9) December 19, 2016
The corresponding RXDISPERR represents the 9th bit
The corresponding RXCHARISK represents the 8th bit
The corresponding RXDATA byte represents the [7:0] bits
shows a waveform at the RX data interface when the decoder receives good data (A),
RXUSRCLK2
RXDATA
RXDISPERR
RXNOTINTABLE
Figure 4-34: RX Data with 8B/10B Errors
www.xilinx.com
A B C
Good Disp Out of
Data Error Table
RX 8B/10B Decoder
D
Both Good
Errors Data
UG482_c4_23_111011
Send Feedback
171