helm/software/matita/contribs/ng_assembly2/emulator/read_write/Freescale_fetch.ma

   1 (**************************************************************************)
   2 (*       ___                                                              *)
   3 (*      ||M||                                                             *)
   4 (*      ||A||       A project by Andrea Asperti                           *)
   5 (*      ||T||                                                             *)
   6 (*      ||I||       Developers:                                           *)
   7 (*      ||T||         The HELM team.                                      *)
   8 (*      ||A||         http://helm.cs.unibo.it                             *)
   9 (*      \   /                                                             *)
  10 (*       \ /        This file is distributed under the terms of the       *)
  11 (*        v         GNU General Public License Version 2                  *)
  12 (*                                                                        *)
  13 (**************************************************************************)
  14
  15 (* ********************************************************************** *)
  16 (*                          Progetto FreeScale                            *)
  17 (*                                                                        *)
  18 (*   Sviluppato da: Ing. Cosimo Oliboni, oliboni@cs.unibo.it              *)
  19 (*   Sviluppo: 2008-2010                                                  *)
  20 (*                                                                        *)
  21 (* ********************************************************************** *)
  22
  23 include "emulator/read_write/fetch_base.ma".
  24 include "emulator/status/status.ma".
  25
  26 (* opcode a byte : HC05 / RS08 *)
  27 (* caricamento solo da segmento 0 *)
  28 ndefinition fetch_byte ≝
  29 λm,t.λs:any_status m t.λpc:word16.
  30  match mem_read t (mem_desc … s) (chk_desc … s) o0 pc with
  31   [ None ⇒ FetchERR ? ILL_FETCH_AD
  32   | Some bh ⇒ fetch_byte_aux m (succc ? pc) bh ].
  33
  34 (* opcode a byte o 0x9E + byte : HC08 / HCS08 *)
  35 (* caricamento solo da segmento 0 *)
  36 ndefinition Freescale_fetch_byte_or_word ≝
  37 λm,t.λs:any_status m t.λpc:word16.
  38  match mem_read t (mem_desc … s) (chk_desc … s) o0 pc with
  39   [ None ⇒ FetchERR ? ILL_FETCH_AD
  40   | Some bh ⇒ match eqc ? bh 〈x9,xE〉 with
  41    [ true ⇒ match mem_read t (mem_desc … s) (chk_desc … s) o0 (succc ? pc) with
  42     [ None ⇒ FetchERR ? ILL_FETCH_AD
  43     | Some bl ⇒ fetch_word_aux m (succc ? (succc ? pc)) 〈bh:bl〉
  44     ]
  45    | false ⇒ fetch_byte_aux m (succc ? pc) bh
  46    ]
  47   ].