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+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||M||                                                             *)
+(*      ||A||       A project by Andrea Asperti                           *)
+(*      ||T||                                                             *)
+(*      ||I||       Developers:                                           *)
+(*      ||T||         The HELM team.                                      *)
+(*      ||A||         http://helm.cs.unibo.it                             *)
+(*      \   /                                                             *)
+(*       \ /        This file is distributed under the terms of the       *)
+(*        v         GNU General Public License Version 2                  *)
+(*                                                                        *)
+(**************************************************************************)
+
+(* ********************************************************************** *)
+(*                          Progetto FreeScale                            *)
+(*                                                                        *)
+(*   Sviluppato da: Ing. Cosimo Oliboni, oliboni@cs.unibo.it              *)
+(*   Sviluppo: 2008-2010                                                  *)
+(*                                                                        *)
+(* ********************************************************************** *)
+
+include "emulator/memory/memory_abs.ma".
+include "emulator/translation/translation.ma".
+include "emulator/status/status_getter.ma".
+
+(* errori possibili nel fetch OPCODE / ILLEGAL ADDRESS *)
+ninductive error_type : Type ≝
+  ILL_OP: error_type
+| ILL_FETCH_AD: error_type
+.
+
+(* - errore: interessa solo l'errore
+   - ok: interessa info, nuovo pc *)
+ninductive fetch_result (A:Type) : Type ≝
+  FetchERR : error_type → fetch_result A
+| FetchOK  : A → word16 → fetch_result A.
+
+ndefinition fetch_byte_aux ≝
+λm:mcu_type.λcur_pc:word16.λbh:byte8.
+ match full_info_of_word16 m (Byte bh) with
+  [ None ⇒ FetchERR ? ILL_FETCH_AD
+  | Some info ⇒ FetchOK ? info cur_pc
+  ].
+
+ndefinition fetch_word_aux ≝
+λm:mcu_type.λcur_pc:word16.λw:word16.
+ match full_info_of_word16 m (Word w) with
+  [ None ⇒ FetchERR ? ILL_FETCH_AD
+  | Some info ⇒ FetchOK ? info cur_pc
+  ].
+
+(* opcode a byte : HC05 / RS08 *)
+ndefinition fetch_byte ≝
+λm:mcu_type.λfR:word32 → option byte8.λpc:word16.
+ match fR (extu_w32 pc) with
+  [ None ⇒ FetchERR ? ILL_FETCH_AD
+  | Some bh ⇒ fetch_byte_aux m (succ_w16 pc) bh ].
+
+(* opcode a byte o 0x9E + byte : HC08 / HCS08 *)
+ndefinition Freescale_fetch_byte_or_word ≝
+λm:mcu_type.λfR:word32 → option byte8.λpc:word16.
+ match fR (extu_w32 pc) with
+  [ None ⇒ FetchERR ? ILL_FETCH_AD
+  | Some bh ⇒ match eq_b8 bh 〈x9,xE〉 with
+   [ true ⇒ match fR (extu_w32 (succ_w16 pc)) with
+    [ None ⇒ FetchERR ? ILL_FETCH_AD
+    | Some bl ⇒ fetch_word_aux m (succ_w16 (succ_w16 pc)) 〈bh:bl〉
+    ]
+   | false ⇒ fetch_byte_aux m (succ_w16 pc) bh
+   ]
+  ].
+
+(* opcode a byte o 0x00 + byte : IP2022 *)
+(* opcode + operando a dimensione fissa 16bit *)
+(* pc word aligned, mappato in 0x02000000-0x0201FFFF *)
+ndefinition IP2022_fetch_byte_or_word ≝
+λm:mcu_type.λfR:word32 → option byte8.λpc:word16.
+ match fR (rol_w32 〈〈〈x0,x1〉:〈x0,x0〉〉.pc〉) with
+  [ None ⇒ FetchERR ? ILL_FETCH_AD
+  | Some bh ⇒ match eq_b8 bh 〈x0,x0〉 with
+   [ true ⇒ match fR (rol_w32 〈〈〈x8,x1〉:〈x0,x0〉〉.pc〉) with
+    [ None ⇒ FetchERR ? ILL_FETCH_AD
+    | Some bl ⇒ fetch_word_aux m (succ_w16 pc) 〈bh:bl〉
+    ]
+   | false ⇒ fetch_byte_aux m (succ_w16 pc) bh
+   ]
+  ].
+
+ndefinition fetch ≝
+λm:mcu_type.λt:memory_impl.λs:any_status m t.
+ match m with
+  [ HC05 ⇒ fetch_byte
+  | HC08 ⇒ Freescale_fetch_byte_or_word
+  | HCS08 ⇒ Freescale_fetch_byte_or_word
+  | RS08 ⇒ fetch_byte
+  | IP2022 ⇒ IP2022_fetch_byte_or_word
+  ] m (mem_read t (mem_desc … s) (chk_desc … s)) (get_pc_reg … s).