Initial public version of Manchester SSEM for SIMH

Initial public version of Manchester University Small Scale Experimental
Machine (SSEM) for SIMH

SSEM/ssem_defs.h

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+/* ssem_defs.h: SSEM (Small Scale Experimental Machine) simulator definitions 
+
+   Based on the SIMH package written by Robert M Supnik
+ 
+   Copyright (c) 2006-2008 Gerardo Ospina
+
+   Permission is hereby granted, free of charge, to any person obtaining a
+   copy of this software and associated documentation files (the "Software"),
+   to deal in the Software without restriction, including without limitation
+   the rights to use, copy, modify, merge, publish, distribute, sublicense,
+   and/or sell copies of the Software, and to permit persons to whom the
+   Software is furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+   THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+   IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+   Except as contained in this notice, the name of the author shall not be
+   used in advertising or otherwise to promote the sale, use or other dealings
+   in this Software without prior written authorization from the author.
+
+   This is not a supported product, but the author welcomes bug reports and fixes.
+   Mail to ngospina@panix.com
+*/
+
+#ifndef _SSEM_DEFS_H_
+#define _SSEM_DEFS_H_    0
+
+#include "sim_defs.h"                                   /* simulator defns */
+
+/* Simulator stop codes */
+
+#define STOP_STOP       1                               /* STOP */
+#define STOP_IBKPT      2                               /* breakpoint */
+
+/* Memory */
+
+#define MEMSIZE         32                              /* memory size */
+#define AMASK           0x1F                            /* addr mask */
+
+/* Architectural constants */
+
+#define MMASK           0xFFFFFFFF                      /* memory mask */
+#define IMASK           0x0000E01F                      /* instruction mask */
+#define UMASK           0xFFFF1FE0                      /* unused bits mask */   
+#define SMASK           0x80000000                      /* sign mask */   
+
+/* Instruction format */
+
+#define I_M_OP          0x07                             /* opcode */
+#define I_V_OP          13
+#define I_OP            (I_M_OP << I_V_OP)
+#define I_GETOP(x)      (((x) >> I_V_OP) & I_M_OP)
+#define I_M_EA          AMASK                           /* address */
+#define I_V_EA          0
+#define I_EA            (I_M_EA)
+#define I_GETEA(x)      ((x) & I_M_EA)
+
+/* Unit flags */
+
+#define UNIT_V_SSEM    (UNIT_V_UF + 0)
+#define UNIT_SSEM      (1u << UNIT_V_SSEM)
+
+/* Instructions */
+
+enum opcodes {
+    OP_JUMP_INDIRECT, OP_JUMP_INDIRECT_RELATIVE, OP_LOAD_NEGATED, OP_STORE,
+    OP_SUBSTRACT, OP_UNDOCUMENTED, OP_TEST, OP_STOP
+    };
+
+/* Prototypes */
+
+uint32 Read (uint32 ea);
+void Write (uint32 ea, uint32 dat);
+
+#endif