GTS Ethernet Hard IP User Guide: Agilex™ 3 FPGAs and SoCs

ID 848477
Date 7/07/2025
Public
Document Table of Contents

3.6. Analog Parameter Options

You can tune the analog functions of GTS PMAs to design high-speed serial protocol solutions by using the transceiver's analog parameter settings. This feature allows you to compensate for signal losses in high-data-rate communications.

To configure the Analog TX and Analog RX parameters of the PMA, access the Analog Parameters tab in the GTS Ethernet Hard IP GUI. When the Ethernet operation mode is set to dynamically reconfigurable, you can configure the analog parameters for each profile separately.

Figure 12. Analog Parameter Options in Parameter Editor
Note: Additionally, you can specify the analog parameters in the .qsf file, which take precedence over the analog parameter settings in the IP GUI. Setting these parameters via the .qsf file overrides the settings in the GUI.
#TX Analog Parameter Configuration
set_instance_assignment -name HSSI_PARAMETER "tx_invert_pin=tx_invert_pin_enable" -to <TX_SERIAL_PIN> -entity <TOP_LEVEL_NAME>
set_instance_assignment -name HSSI_PARAMETER "tx_eq_post_tap_1=5" -to <TX_SERIAL_PIN> -entity <TOP_LEVEL_NAME>
set_instance_assignment -name HSSI_PARAMETER "tx_eq_main_tap=52" -to <TX_SERIAL_PIN> -entity <TOP_LEVEL_NAME>
set_instance_assignment -name HSSI_PARAMETER "tx_eq_pre_tap_1=0" -to <TX_SERIAL_PIN> -entity <TOP_LEVEL_NAME>
set_instance_assignment -name HSSI_PARAMETER "tx_eq_pre_tap_2=0" -to <TX_SERIAL_PIN> -entity <TOP_LEVEL_NAME>

#RX Analog Parameter Configuration
set_instance_assignment -name HSSI_PARAMETER "rx_invert_pin=rx_invert_pin_enable" -to <RX_SERIAL_PIN> -entity <TOP_LEVEL_NAME>
set_instance_assignment -name HSSI_PARAMETER "rx_external_couple_type=RX_EXTERNAL_COUPLE_TYPE_AC" -to <RX_SERIAL_PIN> -entity <TOP_LEVEL_NAME> 
set_instance_assignment -name HSSI_PARAMETER "rx_termination_mode=RX_TERMINATION_MODE_GROUNDED" -to <RX_SERIAL_PIN> -entity <TOP_LEVEL_NAME> 
set_instance_assignment -name HSSI_PARAMETER "rx_onchip_termination_setting=RX_ONCHIP_TERMINATION_SETTING_R_2" -to <RX_SERIAL_PIN> -entity <TOP_LEVEL_NAME>
Table 17.  GTS PMA Analog Parameter Settings
Parameter Values Default Setting Description
Analog TX
Enable TX P&N Invert
  • Enable
  • Disable
Disable Invert TX serial outputs P and N pins.
TX EQ Post Tap 1, 1.0 step size 0 to 19 5 TX equalization control for Post Tap 1.
TX EQ Main Tap, 1.0 step size 0 to 55 52 TX equalization control for Main Tap.
TX EQ Pre Tap 1, 1.0 step size 0 to 15 0 TX equalization control for Pre Tap 1.
TX EQ Pre Tap 2, 1.0 step size 0 to 7 0 TX equalization control for Pre Tap 2.
Analog RX
Enable RX P&N Invert 3
  • Enable
  • Disable
Disable Invert RX serial input P and N pins.
RX External Coupling Mode
  • AC
  • DC
AC Specifies the type of external on-board coupling mode.
Selects value of RX termination mode
  • GROUNDED
  • DIFFERENTIAL
GROUNDED Specifies the RX PMA buffer termination mode.

GROUNDED mode is used for AC-coupled links, while DIFFERENTIAL mode is used for DC-coupled links.

Selects value of RX onchip termination
  • R_1 (50 ohm)
  • R_2 (100 ohm)
R_2 (100 ohm) Selects RX on-chip termination resistor value.
3 This feature is preliminarily and is planned to be fully supported in a future Quartus® Prime Pro Edition software release.