Generate dynamic bundle - chisel

Question

In my project, I have many different custom Bundle.
They can be completely different.
For example these ones:
class MyBundle extends Bundle {
val v1 = UInt(8.W)
val v2 = Bool()
val v3 = UInt(4.W)
}
class MyBundle2 extends Bundle {
val v4 = UInt(18.W)
val v5 = UInt(2.W)
}
...
Instead of manually creating new Bundle to perform each operation, I want to be able to generate for all of them the corresponding Bundle.
So for MyBundle, I want to do:
// Must be generated for each Bundle
class MyGenBundle extends Bundle {
val v1 = UInt(log2Ceil(8 + 1).W) // width = MyBundle.v1 width + 1
val v2 = UInt(log2Ceil(1 + 1).W) // width = MyBundle.v2 width + 1
val v3 = UInt(log2Ceil(4 + 1).W) // width = MyBundle.v3 width + 1
}
class MyModule extends Module {
...
...
val w_b = Wire(new MyBundle())
val w_gb = Wire(new MyGenBundle())
// Must be automated for each Bundle
w_gb.v1 := PopCount(w_b.v1)
w_gb.v2 := PopCount(w_b.v2)
w_gb.v3 := PopCount(w_b.v3)
}
My goal is to automatically generate MyGenBundle (or similar directly in MyModule) from MyBundle, and perform in MyModule the same operation to all signals.
It also means that I need to dynamically address all signals in each Bundle.
Finally, I think the solution can have the following form:
val w_b = Wire(new MyBundle())
val w_gb = Wire(new AutoGenBundle(new MyBundle())) // AutoGenBundle generates a Bundle from parameter
val v_sig = Seq(v1, v1, v3) // Can be recovered automatically
// from w_b.elements I think
foreach (s <- v_sig) {
w_gb."s" := PopCount(w_b."s") // Here "s" the dynamic name of the signal
} // But how in the real case ?
Is this working technically possible in Chisel/Scala?
If so, do you have any ideas for implementing it?

Answer 1

Basic solution is to use the MixedVec chisel type for GenericBundle
class MyBundle extends Bundle {
val v1 = UInt(8.W)
val v2 = Bool()
val v3 = UInt(4.W)
}
class GenericBundle[T <: Bundle](data: T) extends Bundle {
val v = MixedVec(data.elements.values.map(x => UInt(log2Ceil(x.getWidth + 1).W)).toList)
def popCount(data: T): Unit = {
data.elements.values.zip(v).foreach { case (left, right) =>
right := PopCount(left.asUInt())
}
}
}
class MyModule extends MultiIOModule {
val w_b = IO(Input(new MyBundle))
val w_gb = IO(Output(new GenericBundle(w_b)))
w_gb.popCount(w_b)
}