[BUG] <Wrong assignment of X_NUM_RS>

[AyoubJalali]

Is there an existing CVA6 bug for this?

• [X] I have searched the existing bug issues

Bug Description

Hello, I notice that in the cvxif.pkg, the X_NUM_RS is assign by NR_RGPR_PORTS (a constant in the ariane_pkg.sv), hence the X_NUM_RS, can't change only if it changed in the ariane_pg.sv. So what do you think about this ?

[Gchauvon]

Hello, I don't think it is a bug. It is a choice I made when implementing CVXIF in order to not increase size of the register file when cvxif does not need NR_RGPR_PORTS=3. Like a lot of parameters in ariane_pkg.sv, you can modify it. It takes 2 or 3 for value. and both parameters together to avoid miss combination. Maybe it is not the best of implementation, feel free to recommend a better one if you think it is necessary.

[AyoubJalali]

The problem is that if I wanna execute a test with 3 source registers, i should change in the araine_pkg, it's like i change in the RTL, and i don't think it's practical.

[Gchauvon]

Yes if you want to use 3 source registers, you have to change the RTL because it is not the default configuration of CVA6.

[MikeOpenHWGroup]

Hi @Gchauvon, what is the proper value of NR_RGPR_PORTS for the CV32A6 v5.0.0?

[Gchauvon]

It's NR_RGPR_PORTS=2

[Gchauvon]

We could add this parameters in the config_pkg. It can be part of CVA6 parametrization.