Reset Interface Signals

Table 1. Reset Interface
Signal Direction Width Clock Domain Description
HOT_RESET_IN Input 1 AXI_CLK
When this input is asserted in root port mode, the PCIe Controller initiates a hot reset sequence on the PCIe link. The PCIe Controller keeps the PCIe link in hot reset as long as this signal remains asserted.
When de-asserted, the PCIe Controller brings the PCIe link out of hot reset and initiates link training.
HOT_RESET_OUT Output 1 AXI_CLK The PCIe Controller asserts this output when a hot reset is received from the link in endpoint mode. This signal is an active-high output driven synchronous to AXI_CLK.
LINK_DOWN_RESET_OUT Output 1 AXI_CLK The PCIe Controller asserts this output when the LTSSM detects a link-down event (i.e., when the LINK_UP state variable goes to 0). This signal is an active-high output driven synchronous to AXI_CLK. It is asserted high for eight AXI_CLK clock cycles during a link down event.
PERST_N Input 1 Async Triggers a warm reset from the I/O pad.
RESET_REQ Output 1 Async When this signal is asserted, the PCIe Controller requests to trigger a warm or hot reset. Refer to Reset Handshake.
RESET_ACK Input 1 Async Assert this signal to indicate readiness and permission for a warm or hot reset. Refer to Reset Handshake.