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Issue using loop in NIOS


Hey All,

I am using Cyclone 10LP device for my project and development on Quartus 18.0.

Some PIO lines are being used in NIOS II and same have been mapped to VHDL part.

While using any loop statement in NIOS, the updated value of PIO is not reflected in VHDL if we 'Run Configuration' or 'Debug' with Breakpoint.

However, if value of PIO_PTR is added to global watch list and observed at breakpoint, it gets updated in VHDL.

The portion of NIOS code reads like:

int Data[]={32,56,73,55,92}



for (i=0;i<5;i++)


The portion of VHDL code reads like:

if piobs=145 then



end if;

The VHDL part is running in State machine t read value 5 times but led is not glowing in this case.

However, if For loop is removed in NIOS, LED starts glowing.

If for loop is kept then we need to place a breakpoint at x=*piobs_ptr. and then add *piobs_ptr to global watch list and expand in watchlist. This makes LED glow.


Please help is somebody can explain this behavior.






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