Diff b/w if statement & 'ifdef directive

[dinesh.4126]

hi,
can somebody tell me difference b/w if statement and 'ifdef.
When should we go for 'ifdef compile directive.

 

[muni123]

Hi Dinesh,
if-else satement is used to implement a sequential or combinatorial logic within a begin-end block

`ifdef compiler directive is used to specify the simulator to compile certain lines of code b/n `ifdef and `endif statements.

Hope you have got the required answer.
Thanks.

 

[dinesh.4126]

It means if statement is synthesize into gate level but 'ifdef is used in test bench.

 

[muni123]

`ifdef directive not only specifies the simulator tool it also specifies the synthesis tool to synthesize the code b/n `ifdef and `endif if the particular Macro is defined.
So we can implement `ifdef compiler directive in the design code.
it may be utilized for the testbench code too...

 

[shitansh]

Hi,

Go to below topic and see my reply, also take a look at TOP.v file, you will get your answer.



HTH
--
Shitansh Vaghela