set false path in VHDL

[AhmadZaklouta]

I want to write sdc constraint for two signals in VHDL but I am not being able to understand the syntax.

the signals are term_count_internal and time_cnt_wrap_dly

this what I tried but it wrong:

attribute altera_attribute of rtl : architecture is

"-name SDC_STATEMENT""set_false_path -to [get_registers *time_cnt_wrap_dly*]";

   "-name SDC_STATEMENT""set_false_path -from [get_registers *term_count_internal*]""";

can someone guide me on this?

[sstrell]

This seems to explain what you need to do to do this:

https://community.intel.com/t5/Programmable-Devices/Embed-sdc-constraint-in-vhdl-design-file-help-needed/m-p/143162#M43096%3Fwapkw=sdc_statement

[AhmadZaklouta]

I read this but I want to have two set_false_path for two different signal and I am not being able to figure out the syntax.

[SyafieqS]

Ahmad,

You may want to take a look at the KDB below related embed sdc hdl. Hopes it will help as your reference.

[SyafieqS]

How do I embed timing constraints in my HDL file?

https://www.intel.com/content/www/us/en/support/programmable/articles/000078356.html

[AhmadZaklouta]

The VHDL syntax is not clear!
I have tried all these and non work:

attribute altera_attribute of rtl : architecture is "-name SDC_STATEMENT ""set_false_path -to [get_registers *time_cnt_wrap_dly*]"";""-name SDC_STATEMENT ""set_false_path -from [get_registers *term_count_internal*]""";

attribute altera_attribute of rtl : architecture is (
"-name SDC_STATEMENT ""set_false_path -to [get_registers *time_cnt_wrap_dly*]"";" &
"-name SDC_STATEMENT ""set_false_path -from [get_registers *term_count_internal*]""
);

attribute altera_attribute of rtl : architecture is 
"-name SDC_STATEMENT ""set_false_path -to [get_registers *time_cnt_wrap_dly*]"";" &
"-name SDC_STATEMENT ""set_false_path -from [get_registers *term_count_internal*]""";

[sstrell]

No offense, but is there a reason why you don't just use a separate .sdc file?  It will make your life much easier.

[AhmadZaklouta]

We are designing a library that is used accros multiple projects. so we don't have to write constraint for each project when it is embedded in the rtl.

[SyafieqS]

Ahmad,

May I know what Quartus version are you using? Std,Pro?

If Std, there might be some limitation in term of HDL construct and support thus prevent you from to do so.

[AhmadZaklouta]

Quartus prime pro 21.4

[SyafieqS]

Ahmad,

Below are the syntax for altera_attribute package regarding the package for making assignments. Few restrictions of the implication which you can refer in below link for more details.

https://www.intel.com/content/www/us/en/programmable/quartushelp/17.0/hdl/vhdl/vhdl_file_dir_attribute.htm

Quartus only supports altera_attribute on entities, instances, ports, and registers. If applied to any other object, the synthesis attribute is ignored.

[SyafieqS]

Hi Ahmad,

May I know if there is any update?

Are you managed to work on the syntax?

[SyafieqS]

We do not receive any response from you to the previous reply that I have provided, thus I will put this case to close pending. Please post a response in the next 15 days to allow me to continue to support you. After 15 days, this thread will be transitioned to community support. The community users will be able to help you with your follow-up questions.