AR# 8940

説明

General Description: 

When I compile a VHDL program using Synplicity's Synplify 5.3.0, the following error is reported:  

"Process must contain at least one wait."  

What does this error mean, and how do I avoid it?

ソリューション

This error occurs when a user compiles a VHDL design using a process statement that does not include any incoming signals in the sensitivity list of the process. 

For example, the following code would cause the error: 

process 

if ( CLK = '1' and CLK'event ) then 

DATA_OUT <= DATA_IN; 

end if; 

end process; 

The correct way to specify a process is to include all the signals in the sensitivity list, as shown below: 

process ( CLK, DATA_IN ) 

if ( CLK = '1' and CLK'event ) then 

DATA_OUT <= DATA_IN; 

end if; 

end process;