Glitch warnings in Modelsim with Lattice ispLever 7.0

Dec 18, 2007 0 Replies

Hi all,



I'm having trouble trying to figure out why this VHDL synthesizes to something which generates glitches when post-route simulated in Modelsim.



Regardless of what I do, I always get tons of warnings from VitalGlitch in Modelsim about glitches on slices involving "count". I am using Precision to synthesize. These tools are all part of Lattice ispLever v7.0. The clock is 1MHz. This is supposed to be a simple divide by 100 counter.



I don't actually see any glitches as written (although they are reported by modelsim). However, if I remove the range restriction on count, I do see some glitches (this is all in sim...I have not checked for glitches in the actual HW).



Please help!



Thanks,



Sean


Here's the code:



library ieee; use ieee.std_logic_1164.all; use ieee.std_logic_arith.all; use ieee.std_logic_unsigned.all;



entity Tester is PORT (



CLK: IN std_logic; RESET: IN std_logic; CS: IN std_logic; OUTP: OUT std_logic; QA0_d: OUT std_logic; QA1_d: OUT std_logic); end;



architecture RTL of Tester is



COMPONENT clock IS --Divides 1MHz clock down to 10KHz PORT (



--Inputs CLK1M: IN std_logic; --1MHz clock RESET: IN std_logic; --Active Low



--Outputs CLK10K: OUT std_logic); --10KHz clock END COMPONENT; begin div: clock PORT MAP ( CLK1M => CLK, RESET => RESET, CLK10K => OUTP); QA0_d


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