The transmitter pre-emphasis (PRE_EMPHASIS) feature allows pre-emphasis on the drivers for certain I/O standards. This attribute must be used in conjunction 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 Table: Typical Pre-emphasis Gain when Using the PRE_EMPHASIS Attribute in a DDR4 Application .
Attribute |
Value |
Estimated Gain (dB) |
---|---|---|
PRE_EMPHASIS (HP I/O banks) with an OUTPUT_IMPEDANCE of 40 Ω |
RDRV_240 (1) |
2.5 |
Notes: |