Xilinx 7 Series User Manual page 85

Ports and Attributes
Table 3-7
Note:
Table 3-7: TX 8B/10B Encoder Ports
Port
TX8B10BBYPASS[3:0]
TX8B10BEN
TXCHARDISPMODE[3:0]
TXCHARDISPVAL[3:0]
TXCHARISK[3:0]
7 Series FPGAs GTP Transceivers User Guide
UG482 (v1.9) December 19, 2016
lists the ports required by the TX 8B/10B encoder.
There are no TX encoder attributes.
Clock
Dir
Domain
In TXUSRCLK2 This active-High port allows byte-interleaved data to bypass 8B/10B on
a per-byte basis. TX8B10BEN must be High to use this per-byte bypass
mode.
TX8B10BBYPASS [3] corresponds to TXDATA[31:24]
TX8B10BBYPASS [2] corresponds to TXDATA[23:16]
TX8B10BBYPASS [1] corresponds to TXDATA[15:8]
TX8B10BBYPASS [0] corresponds to TXDATA[7:0]
TX8B10BBYPASS[x] = 1, encoder for byte x is bypassed.
TX8B10BBYPASS[x] = 0, encoder for byte x is used.
In TXUSRCLK2 TX8B10BEN is set High to enable the 8B/10B encoder.
TX_DATA_WIDTH must be set to 20 or 40 when the 8B/10B encoder is
enabled.
0: 8B/10B encoder bypassed. This option reduces latency.
1: 8B/10B encoder enabled.
In TXUSRCLK2 Set High to work with TXCHARDISPVAL to force running disparity
negative or positive when encoding TXDATA. Set Low to use normal
running disparity. Refer to
TXCHARDISPMODE[3] corresponds to TXDATA[31:24]
TXCHARDISPMODE[2] corresponds to TXDATA[23:16]
TXCHARDISPMODE[1] corresponds to TXDATA[15:8]
TXCHARDISPMODE[0] corresponds to TXDATA[7:0]
In TXUSRCLK2 Work with TXCHARDISPMODE to provide running disparity control.
Refer to
TXCHARDISPVAL[3] corresponds to TXDATA[31:24]
TXCHARDISPVAL[2] corresponds to TXDATA[23:16]
TXCHARDISPVAL[1] corresponds to TXDATA[15:8]
TXCHARDISPVAL[0] corresponds to TXDATA[7:0]
In TXUSRCLK2 When High, indicates the corresponding data byte on TXDATA is a valid
K character.
TXCHARISK[3] corresponds to TXDATA[31:24]
TXCHARISK[2] corresponds to TXDATA[23:16]
TXCHARISK[1] corresponds to TXDATA[15:8]
TXCHARISK[0] corresponds to TXDATA[7:0]
A TXCHARISK bit should be driven Low when the corresponding
data byte from TXDATA is set to bypass the 8B/10B encoder.
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Description
Table 3-6 for a detailed definition.
Table 3-6 for detailed information.
TX 8B/10B Encoder
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