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The PCIe reset pins for CPM designs must connect to one of specified pins for each of the two
PCIe controllers. The PCIe reset pin for PL PCIe and PHY IP designs can be connected to any
compatible PL pin location, or the CPM PCIe reset pins when the corresponding CPM PCIe
controller is not in use. This is summarized in the following table:
Table 60: PCIe Controller Reset Pin Locations
Versal PCIe Controller
Versal Reset Pin Location
CPM PCIe Controller 0
PS MIO 18
PMC MIO 24
PMC MIO 38
CPM PCIe Controller 1
PS MIO 19
PMC MIO 25
PMC MIO 39
PL PCIe Controllers
Any compatible single-ended PL I/O pin.
Versal ACAP PHY IP
Any compatible single-ended PL I/O pin.
PCIe PHY IP has two Vivado Tcl parameters. lane_reversal with values true or false (Default).
lane_order which is only applicable to x1 and x2 configurations with values bottom (Default) or
Top. For example in a x2 design, by default PIPE signals of the PCIe MAC[1:0] connects to PIPE
signals of the GT QUAD[1:0]. When we apply lane_reversal {true} then PIPE signals of the PCIe
MAC[1:0] connects to PIPE signals of the GT QUAD[0:1]. When we apply lane_order {Top} then
PIPE signals of the PCIe MAC[1:0] connects to PIPE signals of the GT QUAD[3:2].
CPM4 GT Selection
The CPM block within Versal devices has a fixed set of GTs that can be used for each of the two
PCIe controllers. These GTs are shared between the two PCIe controllers and High Speed Debug
Port (HSDP) as such x16 link widths are only supported when a single PCIe controller is in use
and HSDP is disabled. When two CPM PCIe controllers or one PCIe controller and HSDP are
enabled each link will be limited to a x8 link width. GT Quad allocation for CPM happens at GT
Quad granularity and must include all GT Quads from the most adjacent to the CPM to the top-
most GT Quad that is in use by the CPM. GT Quads that are used or between GT Quads that are
used by the CPM (for either PCIe or HSDP) cannot be shared with PL resources even if GTs
within the quad are not in use.
Appendix A: GT Selection and Pin Planning for CPM4
PG346 (v3.3) November 16, 2022
CPM Mode for PCI Express
238