Agilex™ 5 ES Device Errata and User Guidelines

ID 825514
Date 12/09/2024
Public
Document Table of Contents

2.5.9. PERSTn pin from HVIO banks fails to reset PCIe links

Description

For a PCIe link in a transceiver bank, there are two pins in HVIO banks with optional function as PERST# for the PCIe link. You select either one of the reset pins. For the reset pin not used as PERST#, it can be used as a generic HVIO signal. For example, if the PIN_PERST_N_CVP_L1A_0 pin in Bank 5A is assigned as PERST# for the PCIe link in Bank L1A, the PIN_PERST_N_CVP_L1A_1 pin in Bank 5B can be assigned as a generic HVIO.

Due to an issue in ES devices, assigning either of the two PERST# reset pins will not reset the PCIe link. This issue will be fixed in future Quartus® Prime software releases and production devices.

Workaround

Assign both p0_pin_perst_n_i and p0_pin_perst_n_1_i ports to the location of the reset pins in HVIO banks as shown in the following table.

Table 3.  Pin Location Assignment for p0 -pin_perst_n_i and p0_pin_perst_n_1_i Ports
PCle link in GTS Bank HVIO reset pins to pin perst port mapping
p0 -pin_perst_n_i p0_pin_perst_n_1_i

Bank L1A

PIN_PERST _N_CVP_L1A_0 PIN_PERST_N_CVP_L1A_1

Bank L1B

PIN_PERST_N_CVP_L1B_0 PIN_PERST_N_CVP_L1B_1

Bank L1C

PIN_PERST_N_CVP_L1C_0 PIN_PERST_N_CVP_L1C_1

Bank R4A

PIN_PERST_N_R4A_1 PIN_PERST_N_R4A0

Bank R4B

PIN_PERST_N_R4B_1 PIN_PERST_N_R4B_0

Bank R4C

PIN_PERST_N_R4C_1 PIN_PERST_N_R4C_0
Assign weak pull down to the reset pins in the Quartus® Prime software setting file:
  • set_instance_assignment -name WEAK_PULL_DOWN ON -to p0_pin_perst_n_i
  • set_instance_assignment -name WEAK_PULL_DOWN ON -to p0_pin_perst_n_1_i

Connect PERST# to either one of the reset pins. For the other reset pin not used as PERST#, it must be left floating at board level.

For example, for a PCIe link in GTS bank L1A, assign p0_pin_perst_n_i to pin PIN_PERST_N_CVP_L1A_0 and assign p0_pin_perst_n_1_i to pin PIN_PERST_N_CVP_L1A_1.

If you connect PERST# to PIN_PERST_N_CVP_L1A_0, leave PIN_PERST_N_CVP_L1A_1 unconnected at board level.

Tie the i_gpio_perst0_n port to logic high.