How synthesizer implement operation synthesis?

[vaf20]

operation synthesis

hi
i have a basic problem regarding to above issue.for a simple example,suppose "+"operation.
as u know there is many structure and algorithm for add -area usage or speed aside-
i want to add two signal or variable in my HDL code.how synthesizer implement my add operation.the fastest algorithm and high area usage or low speed one with little area usage?
which algorithm?how can i interfere other algorithm?note that synthesizer may be used fast one and high area usage accordingly but i did not speed in my design so i need infer low speed one .
plz help me and comment more about other operation such as muliplication and so on .
tnx in advance

 

[wadaye]

Re: operation synthesis

Hi vaf20:

The tool will determine which adder structure it use if you don't infer the

type you need according the timing you specifed.

If you wanna the tool use the strcuture you wanna, you can instiantiae

it or you can describe the structure use the basic gates.

wang1

 

[vaf20]

Re: operation synthesis

tnx wang1
yes i know,in the case of addition i found synthesiser use carry look ahead ADDER - the fastest alg. - but i want to change synthesizer to get my addition as ripple carry adder .
does anyone know which algorithm synthesizer use when reach '*'?
tnx