How to Initialize a Register of Vectors?

Question

I have defined a register of vectors like this

val my_reg = Reg(Vec(n, Bits(32.W)))

and I access the elements of this register in a for loop using my_reg(i).

Now, I like to initialize this register to zero, so I change the variable definition to this

val my_reg = Reg(Vec(n, Bits(32.W)), init = UInt(0))

However, I get the following compilation error when I want to access the elements of this register

chisel3.core.Data does not take parameters
my_reg(i) := io.a(i)

How can I define a register of vectors and properly initialize them synchronously?

Answer 1

Use RegInit instead. I believe the following statement will do what you want

    val my_reg = RegInit(Vec(Seq.fill(n)(0.U(32.W))))

The Vector is initialized by a Seq of UInt zeros that are 32 bits wide

Answer 2

Looks like in Chisel 3 this should be VecInit instead of Vec:

val initRegOfVec = RegInit(VecInit(Seq.fill(4)(0.U(32.W))))

Source: https://github.com/freechipsproject/chisel3/wiki/Cookbook#how-do-i-create-a-reg-of-type-vec