fork for Matita version B

[helm.git] / matitaB / matita / contribs / ng_assembly2 / emulator / read_write / IP2022_fetch.ma

diff --git a/matitaB/matita/contribs/ng_assembly2/emulator/read_write/IP2022_fetch.ma b/matitaB/matita/contribs/ng_assembly2/emulator/read_write/IP2022_fetch.ma
new file mode 100755 (executable)
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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/read_write/fetch_base.ma".
+include "emulator/status/status.ma".
+
+(* PC word aligned *)
+(* PC < 0x8000 → segmento 1 program ram *)
+(*else         → segmento 2 program flash *)
+ndefinition IP2022_pc_flashtest ≝
+λpc:word16.getMSBc ? pc.
+
+ndefinition IP2022_pc_translation ≝
+λpc:word16.match shlc ? pc with
+ [ pair msb pc' ⇒ pair …
+  match msb with [ true ⇒ o2 | false ⇒ o1 ] pc' ].
+
+(* opcode a byte o 0x00 + byte : IP2022 *)
+(* opcode + operando a dimensione fissa 16bit *)
+ndefinition IP2022_fetch_byte_or_word ≝
+λm,t.λs:any_status m t.λpc:word16.
+ match mem_read t (mem_desc … s) (chk_desc … s)
+                (fst … (IP2022_pc_translation pc))
+                (snd … (IP2022_pc_translation pc)) with
+  [ None ⇒ FetchERR ? ILL_FETCH_AD
+  | Some bh ⇒ match eqc ? bh 〈x0,x0〉 with
+   [ true ⇒ match mem_read t (mem_desc … s) (chk_desc … s)
+                             (fst … (IP2022_pc_translation pc))
+                             (succc ? (snd … (IP2022_pc_translation pc))) with
+    [ None ⇒ FetchERR ? ILL_FETCH_AD
+    | Some bl ⇒ fetch_word_aux m (succc ? pc) 〈bh:bl〉
+    ]
+   | false ⇒ fetch_byte_aux m (succc ? pc) bh
+   ]
+  ].