GTS AXI Streaming Intel® FPGA IP for PCI Express* User Guide

ID 813754
Date 5/15/2024
Public
Document Table of Contents

4.2. Resets

The GTS AXI Streaming IP has two types of resets:

  • Bus Resets—The bus resets are AXI specification defined reset signals, that is used to reset the logic in the GTS AXI Streaming IP interfacing with AXI fabric.
  • IP Resets—The IP reset signals perform cold/warm reset sequences.
The GTS AXI Streaming IP has the following reset domains to drive the various interfaces.
Table 10.  Reset Domains in the GTS AXI Streaming IP
Reset Domain Type Description
Cold reset IP reset

A Fundamental Reset following the application of main power.

Initiated by the assertion i_gpio_perst0_n signal. This resets the following:
  • Bus resets (AXI-Stream/AXI-Lite)
  • Hard IP
  • Sticky registers of configuration space

When cold reset is triggered, warm reset and bus resets must be asserted.

Refer to PCI Express* Base Specification Revision 4.0 for more details on cold reset.

Warm reset IP reset
A Fundamental Reset without cycling main power. This resets the following:
  • Bus resets (AXI-Stream/AXI-Lite)
  • Hard IP

The warm reset can be triggered multiple times by user without going through cold reset sequence. When warm reset is triggered, Bus resets must be asserted.

Refer to the PCI Express* Base Specification Revision 4.0 for more details on warm reset.

AXI-Stream reset Bus reset This resets the AXI-Stream main data path interface (e.g., AXI-Stream TX/RX).
AXI-Lite reset Bus reset This resets the AXI4-Lite Control and Status Register Responder interface (e.g., Completion timeout, control and status register).
For each GTS bank, there are two pins in HVIO banks with optional function as platform reset pin for the PCIe* link in the bank. You can connect PERST# to 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 signal. Resetting a PCIe* link in one bank does not affect the PCIe* links in other banks.
Note: In the current Quartus® Prime software release, connect the PERST# to the i_gpio_perst0_n port of the GTS AXI Streaming IP, tie the p0_pin_perst_n_i port to logic high. Assign the i_gpio_perst0_n port to either one of the reset pin locations in the corresponding HVIO bank. The reset pin in the HVIO bank not used as PERST# can be connected as a generic HVIO signal. The i_gpio_perst0_n only releases PCIe* HIP and GTS transceiver from reset after the FPGA enters user mode. Hence, Configuration-via-Protocol (CvP) is not supported and may not reach PCIe* 1.0/ PCIe* 2.0 L0 state 100 ms after PERST# deactivation during cold reset.

Avoid trigger i_gpio_perst0_n during a Functional Level Reset or before a Functional Level Reset completion. The minimum interval requirement between two consecutive reset is 500 μs. It is applicable to PERST# and hot reset. In the other words, the minimum interval time required between the deassertion of the PERST# to the assertion of the next PERST# is 500 μs.

For a description of the dual-purpose pins in the HVIO banks function as PCIe* platform reset, refer to the Pin Connection Guidelines: Agilex™ 5 FPGAs and SoCs .
Figure 9. Reset Domains