Using --freqhz for Clock Management - 2024.2 English - UG1700

Data Center Acceleration Using Vitis User Guide (UG1700)

Document ID
UG1700
Release Date
2025-01-15
Version
2024.2 English

Resource Identifier

The value of clock directive --freqhz supports either no units or MHz. For example, to connect clock frequency 100 MHz to any kernel in v++ command, --freqhz can be given as: --freqhz=100000000 or --freqhz=100MHz. The unit MHz is case insensitive and supports values using up to 6 decimals. Example, --freqhz=312.005MHz is supported whereas --freqhz=312.0000005MHz is not supported.

The process for managing clock frequencies is specified below:

Default Values

The default clock is derived from the platform, which is passed to the v++ option and can be overridden using the ----freqhz option.

v++ -c --mode hls

The default clock is derived from the platform, and can be overridden using the --freqhz option. Specifying a different --hls.clock frequency will result in an error during the v++ --mode hls option.

--freqhzcan be specified in v++ -c --mode hls as:

v++ -c --mode hls –platform <pfm_name> --freqhz=150000000 -–config hls.cfg
--freqhz can be specified in the configuration file as:
v++ -c --mode aie --platform  <pfm_name> --config hls.cfg
In hls.cfg, --freqhz can be given as:
[clock]
freqhz=200000000 OR freqhz=200MHz

v++ --link

--platform
The default clock is derived from the platform, and can be overridden using the --freqhz option.
v++ -l -t hw –platform <pfm_name> --freqhz=200000000:mm2s \
--freqhz=200MHz:s2mm –config system.cfg
In system.cfg, --freqhz can be given as:
[clock]
freqhz=200000000:vadd.clk OR freqhz=200MHz:vadd.clk