Intel® Quartus® Prime Software
Intel® Quartus® Prime Design Software, Design Entry, Synthesis, Simulation, Verification, Timing Analysis, System Design (Platform Designer, formerly Qsys)
Announcements
Intel Support hours are Monday-Fridays, 8am-5pm PST, except Holidays. Thanks to our community members who provide support during our down time or before we get to your questions. We appreciate you!

Need Forum Guidance? Click here
Search our FPGA Knowledge Articles here.
15332 Discussions

Concatenation operator in a port assignment ?

RHerm1
Beginner
279 Views

I'm using Quartus 18.1.1 / Build 646 and have observed a strange behavior with the following VHDL code:

meta_data_ram : altsyncram generic map ( ....... ) port map ( address_a => md_upper_reg & channel_inreg; ..... );

The issue concerns the port "address_a": With Signal Tap I see the following values:

md_upper_reg = '1' and channel_inreg = "00000"

==> address_a is "000001" instead of "100000" as expected

 

When I change the code like this...

md_wr_addr <= md_upper_reg & channel_inreg;   meta_data_ram : altsyncram generic map ( ... ) port map ( address_a => md_wr_addr, .........

everything works fine !!

 

If the compiler can't handle the concatenation operator in a port assignment I would expect that there is either an error or the signal assignment is done correctly!

Did I miss something or is this a Quartus issue?

0 Kudos
3 Replies
MEIYAN_L_Intel
Employee
78 Views

Hi,

 

I had found out that it might be due to the VHDL version used in Quartus.

For an example here:

In VHDL 2008:

comp_inst : comp

port map(

thing => "000" & sig

);

 

In VHDL 93:

tempsig <= "000" & sig;

comp_inst : comp

port map(

thing => tempsig

);

 

You may check your VHDL version in by clicking assignment >settings>VHDL input.

 

Thanks

 

 

 

RHerm1
Beginner
78 Views

Thanks for your reply,

 

I'm using VDHL 2008 and the issue is that a wrong value is assigned to the port "address_a". When I assign the same expression to a signal first and then this signal to a port it works!!

MEIYAN_L_Intel
Employee
78 Views

Hi,

May I know any new issue facing?

Thanks.

 

Reply