To create designs with IP integrator that function correctly on the target hardware, you must understand reset and clocking considerations. This chapter provides information about clock and reset connectivity at the system level. In the Vivado® IP integrator, you can use the Xilinx® platform board flow, which enables you to configure IP in your design to connect to board components using signal interfaces in an automated manner. You can also make all the connections manually. The examples and overall flow described in this chapter use the platform board flow, but the considerations are valid for all block designs.
For designs using the Memory IP core, the core provides the clock source, and the primary clock from the board oscillator must be connected directly to the Memory IP core. For more information, see Designing with the Memory IP Core.
The Memory IP core can generate up to five additional clocks (Memory IP core for UltraScale devices can generate only four additional clocks), which you can use for resetting the design as needed. For designs that contain a Memory IP core, ensure that the primary onboard clock is connected to memory controller, and then use the user clock (
ui_clock or the
ui_addn_clk_x) as additional clock sources for the rest of the design.
For IP integrator designs with platform board flow, specific IP (for example, Memory IP and Clocking Wizard) support board-level clock configuration. For the rest of the system, clocking can be derived from the supported IP. Similarly, for driving reset signals, board-level reset configuration is supported by a specific reset IP (for example,
proc_sys_reset). You can use other IP that also require external reset but are not currently supported by the platform board flow.
The following sections describe the reset topologies for different types of designs.