Control detect, Figure 5–10, Figure 5–10. disparity error – Altera Stratix GX Transceiver User Manual
Page 126
5–14
Altera Corporation
Stratix GX Transceiver User Guide
January 2005
XAUI Mode Receiver Architecture
Figure 5–10. Disparity Error
Control Detect
The 8B/10B has the ability to differentiate between data and control codes
via the rx_ctrldetect port. If this port is not in use, there is no way to
differentiate Dx.y from Kx.y.
shows an example waveform demonstrating the detection of
a K28.5 code (BC + ctrl). The rx_ctrldetect=1'b1 is aligned with
8'hbc
, which indicates that this code is a control code. The reset of the
code received is data.
Figure 5–11. Control Code Detection
clock
rx_out[7:0 ]
rx_disperr
07
07
07
07
07
07
rx_ctrldetect
07
Expected RD code
rx_in
17C
283
17C
283
283
283
17C
17C
RD-
RD+
RD+
RD-
RD-
RD-
RD+
RD-
RD code received
RD-
RD+
RD+
RD-
RD+
RD-
RD+
RD-
n
n+1
n+2
n+3
n+4
n+5
n+6
n+7
rx_errdetect
FE
clock
rx_out[7:0]
rx_ctrldetect
83
78
BC
07
0F
00
BF
3C
D3.4
D24.3
D28.5
K28.5
D15.0
D0.0
D31.5
D28.1
Code Group