helm/software/matita/contribs/ng_assembly/emulator/read_write/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/memory/memory_abs.ma".
  24 include "emulator/translation/translation.ma".
  25 include "emulator/status/status_getter.ma".
  26
  27 (* errori possibili nel fetch OPCODE / ILLEGAL ADDRESS *)
  28 ninductive error_type : Type ≝
  29   ILL_OP: error_type
  30 | ILL_FETCH_AD: error_type
  31 .
  32
  33 (* - errore: interessa solo l'errore
  34    - ok: interessa info, nuovo pc *)
  35 ninductive fetch_result (A:Type) : Type ≝
  36   FetchERR : error_type → fetch_result A
  37 | FetchOK  : A → word16 → fetch_result A.
  38
  39 ndefinition fetch_byte_aux ≝
  40 λm:mcu_type.λcur_pc:word16.λbh:byte8.
  41  match full_info_of_word16 m (Byte bh) with
  42   [ None ⇒ FetchERR ? ILL_FETCH_AD
  43   | Some info ⇒ FetchOK ? info cur_pc
  44   ].
  45
  46 ndefinition fetch_word_aux ≝
  47 λm:mcu_type.λcur_pc:word16.λw:word16.
  48  match full_info_of_word16 m (Word w) with
  49   [ None ⇒ FetchERR ? ILL_FETCH_AD
  50   | Some info ⇒ FetchOK ? info cur_pc
  51   ].
  52
  53 (* opcode a byte : HC05 / RS08 *)
  54 ndefinition fetch_byte ≝
  55 λm:mcu_type.λfR:word32 → option byte8.λpc:word16.
  56  match fR (extu_w32 pc) with
  57   [ None ⇒ FetchERR ? ILL_FETCH_AD
  58   | Some bh ⇒ fetch_byte_aux m (succ_w16 pc) bh ].
  59
  60 (* opcode a byte o 0x9E + byte : HC08 / HCS08 *)
  61 ndefinition Freescale_fetch_byte_or_word ≝
  62 λm:mcu_type.λfR:word32 → option byte8.λpc:word16.
  63  match fR (extu_w32 pc) with
  64   [ None ⇒ FetchERR ? ILL_FETCH_AD
  65   | Some bh ⇒ match eq_b8 bh 〈x9,xE〉 with
  66    [ true ⇒ match fR (extu_w32 (succ_w16 pc)) with
  67     [ None ⇒ FetchERR ? ILL_FETCH_AD
  68     | Some bl ⇒ fetch_word_aux m (succ_w16 (succ_w16 pc)) 〈bh:bl〉
  69     ]
  70    | false ⇒ fetch_byte_aux m (succ_w16 pc) bh
  71    ]
  72   ].
  73
  74 (* opcode a byte o 0x00 + byte : IP2022 *)
  75 (* opcode + operando a dimensione fissa 16bit *)
  76 (* pc word aligned, mappato in 0x02000000-0x0201FFFF *)
  77 ndefinition IP2022_fetch_byte_or_word ≝
  78 λm:mcu_type.λfR:word32 → option byte8.λpc:word16.
  79  match fR (rol_w32 〈〈〈x0,x1〉:〈x0,x0〉〉.pc〉) with
  80   [ None ⇒ FetchERR ? ILL_FETCH_AD
  81   | Some bh ⇒ match eq_b8 bh 〈x0,x0〉 with
  82    [ true ⇒ match fR (rol_w32 〈〈〈x8,x1〉:〈x0,x0〉〉.pc〉) with
  83     [ None ⇒ FetchERR ? ILL_FETCH_AD
  84     | Some bl ⇒ fetch_word_aux m (succ_w16 pc) 〈bh:bl〉
  85     ]
  86    | false ⇒ fetch_byte_aux m (succ_w16 pc) bh
  87    ]
  88   ].
  89
  90 ndefinition fetch ≝
  91 λm:mcu_type.λt:memory_impl.λs:any_status m t.
  92  match m with
  93   [ HC05 ⇒ fetch_byte
  94   | HC08 ⇒ Freescale_fetch_byte_or_word
  95   | HCS08 ⇒ Freescale_fetch_byte_or_word
  96   | RS08 ⇒ fetch_byte
  97   | IP2022 ⇒ IP2022_fetch_byte_or_word
  98   ] m (mem_read t (mem_desc … s) (chk_desc … s)) (get_pc_reg … s).