Blocks are grouped together in Vitis Model Composer by using a Subsystem. Subsystems can also be used to group blocks within a clock domain. Clock settings for each subsystem can then be controlled by enabling multiple clocks on the HDL Settings tab of the Vitis Model Composer Hub block.
In the previous figure, a clock domain Subsystem called src_domain has been created. On the
HDL
Settings tab, the FPGA clock period has been
set to (1000/368) ns (368 MHz) and the Simulink system period to 1 sec. This implies that an
advance of 1 Simulink second corresponds
to (1000/368) ns of FPGA clock.
Similarly, another group of blocks representing another clock
domain is included in a Subsystem called dest_domain. This
Subsystem is configured to run at an FPGA clock period of 1000/245 ns (245
MHz). The Simulink system period is set to 368/245. This
is done because the Simulink system period of the
src_domain Subsystem is set to 1. Hence, you
normalize the System period from the faster src_domain.