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Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

code problem

Hi, I am wring a mermory code, but the waveform is not correct. There is no change of fin_add, only when add_en='1' then add_en_next change. I think probable it is coz the used(num) never become zero...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

I was just describing the situation why the "fin_add" never changes. At the beginning there is the code

--- Quote Start ---

process (init,add_en,num,used)

begin

fin_init<='0';

fin_add<='0';

--- Quote End ---

and logically there should be a change of the fin_add after something changed in the sensivity list.

But since the process exectution enters the IF branch - fin_add<='1' and only last assignment in the process takes place. Therefore he will not notice '0' assignment on the waveform.

Thats true

If his fin_add always = '1' this means that his process always enters to the branch there fin_add assigned '1'.

The problem can be in the testbench.