Question about generics in VHDL

[Fatherc0stas]

Hello everyone, I am currently in the middle of a VHDL project in my university and iw anted to ask a few questions on some ideas i have in ways to improve my design. The design is a generic type of decoder (in this case, 7/4 and 15/11 are included in the errorcorrection parts fo the program)

The program i have looks like this(and it works fine in both functions, 7/4 and 15/11):



My question is: Is there a way to be able to change the generic values from a pin assigned in my entity section? i intend to use the pin named "func" for that purpose. for example, when "func" is 1 then IPbits = 7 and OPbits = 4 and when "func" =0 then IPbits = 15 and OP bits = 11.

I am wondering if its possible to achieve this sort of function from within vhdl.

Thanks alot for your time

 

[TrickyDicky]

No, you cannot change generic values in real time. That would be like changing the number of pins on a chip while the chip is running.

Generics are for initial set up purposes.

 

[Fatherc0stas]

No, you cannot change generic values in real time. That would be like changing the number of pins on a chip while the chip is running.

Generics are for initial set up purposes.

Thanks for the quick reply TrickyDicky, is there any other way of making this happen? maybe use a type of variable (if possible) to replace the generics? My VHDL knowledge is fairly limited as i have only started to study it 3 months ago and im wondering if there is any way to implement this.

 

[FvM]

First comment, you need to learn how to post code at ebaboard. It's really annoying to read it as a blurred screen shot....

Secondly, please consider on your own what you want to achieve hardware-wise.

There are cases where a common logic design is used for product variants with different functionality, controlled by a configuration pin. You either need to implement both logic functions separately and have multiplexers switching between both. Or if one is a superset of the other, implement the larger function and disable part of it conditionally, possibly switching some functional details.