The transmitter pre-emphasis (PRE_EMPHASIS) feature (HP I/O banks only) allows pre-emphasis on the drivers for certain I/O standards. This attribute must be used with ENABLE_PRE_EMPHASIS.
The allowed values for the PRE_EMPHASIS attribute are:
- PRE_EMPHASIS = RDRV_NONE (default)
- PRE_EMPHASIS = RDRV_240 (where ENABLE_PRE_EMPHASIS must be set to TRUE)
The PRE_EMPHASIS attribute uses the following syntax in the XDC file:
set_property PRE_EMPHASIS value [get_ports port_name ]
A typical pre-emphasis gain when using the PRE_EMPHASIS attribute in a DDR4 application with an OUTPUT_IMPEDANCE of 40 Ω is listed in the following table.
| Attribute | Value | Estimated Gain (dB) |
|---|---|---|
| PRE_EMPHASIS (HP I/O banks) with an OUTPUT_IMPEDANCE of 40 Ω. | RDRV_240 1 | 2.5 |
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