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Altera_Forum's avatar
Altera_Forum
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15 years ago

Using multiple LPMs of same type but different characteristics

Hi all, I was trying to find a way to use the sam LPM Megafunction but with different settings. For example, the lpm_add_sub function, I would like to have both an adder and subtractor but can...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

At some point the compiler will search for the entity "lpm_sub", which you probably haven't created as you want to invoke an existing LPM function. Hence the error.

LPM_TYPE is to be seen as a constant rather than a parameter. LPM functions go back a long time, at some point it was an industry standard.

You could do it like this 


library lpm ;
  use lpm.lpm_components.all ;
- - -
lpm_sub_component1 : lpm_add_sub
  generic map (
    lpm_direction : STRING := "ADD";
    . . . 
    )
  port map ( 
     . . .
     ) ;
lpm_sub_component2 : lpm_add_sub
  generic map (
    lpm_direction : STRING := "SUB";
    . . . 
    )
  port map ( 
     . . .
     ) ;