下面的vhdl写法是否合法？

只看该作者 · 2007-5-11 15:20

我的疑问是when的分支是否可以加上begin和end？

case key is
    when ''11111110'' =>
    begin
         p <= 0 ;
         q <= 1 ;
    end
    when ''11111101'' =>
    begin
         p <= 1 ;
         q <= 2 ;
    end
    when ''11111011'' =>
    begin
         p <= 2 ;
         q <= 3 ;
    end
    when ''11110111'' =>
    begin
         p <= 3 ;
         q <= 4 ;
    end
    when ''11101111'' =>
    begin
         p <= 4 ;
         q <= 5 ;
    end
    when ''11011111'' =>
    begin
         p <= 5 ;
         q <= 6 ;
    end
    when ''10111111'' =>
    begin
         p <= 6 ;
         q <= 7 ;
    end
    when ''01111111'' =>
    begin
         p <= 7 ;
         q <= 0 ;
    end
    when others =>
         spken <= '0';