Hello, Suppose we have 4 buffer, each has a single bit which indicates if the buffer is empty and we connect this pin to the bellow signal. signal buffer_empty : std_logic_vector (3 downto 0); Each bit of the above signal indicates whether the corresponding buffer is empty or not and the below signal indicates whether we have an empty buffer al all. signal any_buffer_empty : std_logic; The second signal can be assigned as follows: any_buffer_empty <= buffer_empty (0) and buffer_empty (1) and buffer_empty (2) and buffer_empty (3); Now the problem gets difficult for me if the number of buffers is parameterized (by a generic or constant like NR_BUFF) and I cannot figure out how to calculate the second signal in this case. Thanks in advance, Hamid
Hamidreza A. wrote: > and I cannot figure out how to calculate the second signal in this case. Check out the package reduce_pack and in there the functions or_reduce() as well as and_reduce(). See this also: http://www.edaboard.com/thread253196.html
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Edited by Moderator
You can also use the following
1 | -- bit-wise or
|
2 | any_buffer_empty <= '0' when buffer_empty=(buffer_empty'range=>'0') else |
3 | '1'; |
4 | --bit-wise and
|
5 | all_buffer_empty <= '1' when buffer_empty=(buffer_empty'range=>'1') else |
6 | '0'; |
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