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ARuss12's avatar
ARuss12
Icon for New Contributor rankNew Contributor
6 years ago
Solved

Modelsim 10.1d and UNDEFINED entities internal signals

Good morning all, This is my first post in this forum, so i apologize in advance if the section is not completely correct. I started recently wih FPGA design, and i am doing some homeworks from my ...
  • Vicky1's avatar
    Vicky1
    6 years ago

    Hi,

    Thanks for the project file.

    Please initialize the all the I/os in test bench like below, then Add the internal signals like 'FF1' & 'FF2' in wave window & try to 'run simulation'.

    please find the attachment for screenshot. 

    SIGNAL STOP : STD_LOGIC := '0';
SIGNAL EnDig1 : STD_LOGIC:= '0';
SIGNAL EnDig3 : STD_LOGIC:= '0';
SIGNAL START : STD_LOGIC:= '0';
SIGNAL LED : STD_LOGIC:= '0';
SIGNAL EnDig0 : STD_LOGIC:= '0';
SIGNAL Digits : STD_LOGIC_VECTOR(6 DOWNTO 0):= "0000000";
SIGNAL EnDig2 : STD_LOGIC := '0';
SIGNAL CLK : STD_LOGIC:= '0';

    Regards,

    Vicky

ARuss12's avatar
ARuss12
Icon for New Contributor rankNew Contributor
6 years ago

Thanks for your answer! My bad, the pic is too zoomed and the clock looks still, but it's actually toggling. I am attaching the .qar file as requested.

I corrected some things but i still see a behavior that i can't understand. In particular, it looks like the internal signals of my entites are not correct if not brought "outside" as output of the top entity simulated in the testbench. For example, the signal "enableFromFF" is istantiated in the top entity "ReactionTimer.vhd". If selected in the object menu and plotted in the waveform, it has a (wrong) behavior. If i put this signal as an output of the entity "ReactionTimer.vhd" and visualize it directly from the testbench entity, it has a different (and correct, as expected) behavior. The only difference is that i acces to this signal INSIDE the entity "ReactionTimer", or as an output from it. See the newly attached pictures that describe this behavior.

Comparison of the two EnableFromFF signals, seen in the entity and in the testbench (extracted as output)

TestBench vs top entity "ReactionTimer"