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Altera_Forum
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8 years ago

Bit memorisation in if statement

Hi everyone, First i'm sorry because i'm french, so my english may be bad. My project consists to control many servo-motors via the DE0 Nano Board via UART. In order to do that, i send s...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
8 years ago

Looking at other people's code is never very easy without the whole code and a testbench and some time. But then its usually much easier to debug it yourself. Altera provide modelsim for free. Have you tried using that?

Notes on your code: 


if((rx_buffer(d_width DOWNTO 1) = "00101100") and block_state = '1') then
    compteur <= compteur + 1;
    block_state <= '0';
else

If d_width is NOT 8, then this statement will always be FALSE. Comparing two vectors of different lengths always returns false without any warnings. The same with the /= comparisons. If DWIDTH /= 8 then all of the /= compares will always be TRUE.