Resets - 3.0 English

AXI Bridge for PCI Express Gen3 Subsystem Product Guide (PG194)

Document ID
PG194
Release Date
2022-11-16
Version
3.0 English

For endpoint configurations, the sys_rst_n signal should be driven by the PCI Express® edge connector reset (perstn). This serves as the reset for the PCI Express interface.

The axi_aresetn output the AXI reset signal synchronous with the clock provided on the axi_aclk output. This reset should drive all corresponding AXI Interconnect aresetn signals.

The following figure shows the Endpoint system reset connection for the core in an UltraScale™ device.

Figure 1. Endpoint System Reset Connection (UltraScale Devices)

The following figure shows the Endpoint system reset connection for the core in an UltraScale+ device.

Figure 2. Endpoint System Reset Connection (UltraScale+ Devices)

For Root Port configurations, the sys_rst_n signal is internally generated by the user design. This serves as the reset to the PCI Express slot connector reset (perstn).

The following figure shows the Root Port system reset connection for the core in an UltraScale device.

Figure 3. Root Port System Reset Connection (UltraScale Devices)

The following figure shows the Root Port system reset connection for the core in an UltraScale+ device

Figure 4. Root Port System Reset Connection (UltraScale+ Devices)

Available for the DMA/Bridge Subsystem for PCIe in AXI Bridge mode, there is an optional dma_bridge_resetn input pin which allows you to reset all internal Bridge engines and registers as well as all AXI peripherals driven by axi_aresetn and axi_ctl_aresetn pins. When the following parameter is set, dma_bridge_resetn does not need to be asserted during initial link up operation because it will be done automatically by the IP. You must terminate all transactions before asserting this pin. After being asserted, the pin must be kept asserted for a minimum duration of at least equal to the Completion Timeout value (typically 50 ms) to clear any pending transfer that may currently be queued in the data path. To set this parameter, type the following command at the Tcl command line:

set_property -dict [list CONFIG.soft_reset_en {true}] [get_ips <ip_name>]