Re: [myhdl-list] enums and non-local

[Henry G. <he...@ca...>]

On 11/02/15 15:47, Jose M. Gomez Cama wrote:
> This is a piece of code that does not work. I think it is more or less equivalent to yours.
>
>
> from myhdl import *
>
> def test(clk, reset, a, b):
>      t_state = enum("WAIT", "CALC")
>      state = Signal(t_state.WAIT)
>      @always_seq(clk.posedge, reset)
>      def fsm():
>          if state == t_state.WAIT:
>              b.next = 0
>              state.next = t_state.CALC
>          elif state == t_state.CALC:
>              a.next = b
>              state = t_state.WAIT
>      return fsm
>
> clk = Signal(intbv(0)[1:])
> reset = ResetSignal(1, active=1, async=False)
> a = Signal(intbv(0)[1:])
> b = Signal(intbv(0)[1:])
>
> toVHDL(test, clk, reset, a, b)
>
> The error is:
>
> Local variable may be referenced before assignment: state

You're trying to assign state here:

         elif state == t_state.CALC:
             a.next = b
             state = t_state.WAIT

Perhaps you want `state.next = t_state.WAIT`?

Henry