Error when using with-select-when in VHDL

Ayush K. (ayushkhemka) OP 2014-11-04 21:28 #3870274

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Can someone explain to me this error and how to solve it?

architecture xxx of yyy is
signal wrptr,rdptr: std_logic_vector(n-1 downto 0);
process(reset,clk)
end process;
with rdptr select
with wrptr select
process(we,dmuxout)
end process;
end xxx;


The errors are:

Illegal expression
xx.vhd, 40
  with rdptr select
  Expression must be the name of an object whose subtype is locally static, or
  it must be a qualified expression or type conversion whose type mark denotes
  a locally static subtype.
Illegal expression
xx.vhd, 40
  with wrptr select
  Expression must be the name of an object whose subtype is locally static, or
  it must be a qualified expression or type conversion whose type mark denotes
  a locally static subtype.

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Lothar M. (lkmiller) Moderator (Company: Titel) 2014-11-04 22:15 #3870360

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The with-select is a concurrent statement. It cannot be used inside a 
process. Use the case-when instead...

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Ayush Khemka Guest 2014-11-05 02:28 #3870590

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I did put it outside the process. It can be seen in the code clearly.

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Lothar M. (lkmiller) Moderator (Company: Titel) 2014-11-05 07:50 #3870649

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Ayush Khemka wrote:
> It can be seen in the code clearly.
Ok, I see. But then the problem is not in the posted code.

> signal wrptr,rdptr: std_logic_vector(n-1 downto 0);
> Expression must be the name of an object whose subtype is locally static
Where does n come from?