Constants in Verilog

[Altera_Forum]

Hi, 

 I have a IP coded in verilog. The simulator used in Modelsim and Synthesizer is Quartus II. This IP is going to Stratix FPGA with other IP's. I am confused about the usage of 'define and parameters in the IP.  There are some constants, few are defined as parameters and some are constants.  Please help to identify the basic difference between these two wrt simulation and synthesis. Is there any problem with 'define if the IP goes to SoC level.  Please guide me.  Regards, freak

[Altera_Forum]

Hi. 

There's an excellent paper explaining parameters, `defines and defparams: http://www.sunburst-design.com/papers/cummingshdlcon2002_parameters.pdf

[Altera_Forum]

That was a nice read. Thanks for the link. 

 I had to laugh every time he slammed authors of other books for what he deemed as "mis-information".   He was quite opinionated, but backed it up nicely with his explainations and examples.

[Altera_Forum]

--- Quote Start ---  He was quite opinionated, but backed it up nicely with his explainations and examples.  --- Quote End ---   Cliff Cummings is allowed to be opinionated because he is absolutely brilliant when it comes to HDL coding styles and practices. Almost every single paper he has written has won first/second place at various national HDL conferences. You should read _all_ of his papers - they will make you a much better HDL programmer - I keep all his papers on my bookshelf and reference them as I would HDL text books.