-- FILE : accum.ads
-- DATE : 7/98
-- AUTHOR : Sy Wong
-- AIM : Specification of accumulator design

with HDL;
generic
  N: positive; -- total bits
package ACCUM is
  type device_state is limited private;
  type device is
  record
    carry_in:  HDL.input:= false;
    data_in, accumulator: HDL.bus(0..N-1):= (0..N-1 => FALSE);
    -- bit 0 is LS
    carry_out: HDL.output:= FALSE;
    add:  HDL.input:= FALSE;
    state: device_state;
  end record;
  procedure update (d: in out device);
private
  type device_state is
  record
    add: boolean:= FALSE;
  end record;
end ACCUM;