Often designs have multiple paths sharing the NoC, but without all paths needing maximum bandwidth simultaneously. Rather, some paths might be active during one phase of activity, while others are idle. During another phase, the original paths might require less bandwidth, while the paths that had been idle might require more bandwidth. If the design assumes that all paths require their maximum possible bandwidth at all times, the NoC compiler might not be able to find a solution that satisfies all the bandwidth requirements simultaneously. In these cases, it can be beneficial to define different traffic phases.
To enable Multiphase NoC Mode, after creating the project, define the different phases
with set_property NOC_PHASES. For example, the following command
defines three traffic phases.
set_property NOC_PHASES “boot_phase, config_phase, end_phase” [current_project]This command only needs to be run once and is applied to all NoC IP instances in the
design. It adds a new Multiphase Mode column to
the QoS tab. By checking the
Multiphase Mode check box next to a path,
you can specify read and write bandwidth on a per-phase basis. In this example, the path
from S00_AXI to M00_AXI has different bandwidths
specified for boot_phase, config_phase, and
end_phase. Paths without multiphase checked are assumed to have the
same bandwidth for all phases.