1 /*****************************************************************************/
5 /* Instruction encoding for the ca65 macroassembler */
9 /* (C) 1998-2003 Ullrich von Bassewitz */
10 /* Römerstrasse 52 */
11 /* D-70794 Filderstadt */
12 /* EMail: uz@cc65.org */
15 /* This software is provided 'as-is', without any expressed or implied */
16 /* warranty. In no event will the authors be held liable for any damages */
17 /* arising from the use of this software. */
19 /* Permission is granted to anyone to use this software for any purpose, */
20 /* including commercial applications, and to alter it and redistribute it */
21 /* freely, subject to the following restrictions: */
23 /* 1. The origin of this software must not be misrepresented; you must not */
24 /* claim that you wrote the original software. If you use this software */
25 /* in a product, an acknowledgment in the product documentation would be */
26 /* appreciated but is not required. */
27 /* 2. Altered source versions must be plainly marked as such, and must not */
28 /* be misrepresented as being the original software. */
29 /* 3. This notice may not be removed or altered from any source */
32 /*****************************************************************************/
46 /*****************************************************************************/
48 /*****************************************************************************/
52 /* Constants for the addressing mode. If an opcode is available in zero page
53 * and absolut adressing mode, both bits are set. When checking for valid
54 * modes, the zeropage bit is checked first. Similar, the implicit bit is set
55 * on accu adressing modes, so the 'A' for accu adressing is not needed (but
57 * When assembling for the 6502 or 65C02, all addressing modes that are not
58 * available on these CPUs are removed before doing any checks.
60 #define AM_IMPLICIT 0x00000003UL
61 #define AM_ACCU 0x00000002UL
62 #define AM_DIR 0x00000004UL
63 #define AM_ABS 0x00000008UL
64 #define AM_ABS_LONG 0x00000010UL
65 #define AM_DIR_X 0x00000020UL
66 #define AM_ABS_X 0x00000040UL
67 #define AM_ABS_LONG_X 0x00000080UL
68 #define AM_DIR_Y 0x00000100UL
69 #define AM_ABS_Y 0x00000200UL
70 #define AM_DIR_IND 0x00000400UL
71 #define AM_ABS_IND 0x00000800UL
72 #define AM_DIR_IND_LONG 0x00001000UL
73 #define AM_DIR_IND_Y 0x00002000UL
74 #define AM_DIR_IND_LONG_Y 0x00004000UL
75 #define AM_DIR_X_IND 0x00008000UL
76 #define AM_ABS_X_IND 0x00010000UL
77 #define AM_REL 0x00020000UL
78 #define AM_REL_LONG 0x00040000UL
79 #define AM_STACK_REL 0x00080000UL
80 #define AM_STACK_REL_IND_Y 0x00100000UL
81 #define AM_IMM_ACCU 0x00200000UL
82 #define AM_IMM_INDEX 0x00400000UL
83 #define AM_IMM_IMPLICIT 0x00800000UL
84 #define AM_IMM (AM_IMM_ACCU | AM_IMM_INDEX | AM_IMM_IMPLICIT)
85 #define AM_BLOCKMOVE 0x01000000UL
87 /* Bitmask for all ZP operations that have correspondent ABS ops */
88 #define AM_SET_ZP (AM_DIR | AM_DIR_X | AM_DIR_Y | AM_DIR_IND | AM_DIR_X_IND)
90 /* Bitmask for all ABS operations that have correspondent FAR ops */
91 #define AM_SET_ABS (AM_ABS | AM_ABS_X)
93 /* Bit numbers and count */
94 #define AMI_IMM_ACCU 21
95 #define AMI_IMM_INDEX 22
100 /* Description for one instruction */
101 typedef struct InsDesc InsDesc;
104 unsigned long AddrMode; /* Valid adressing modes */
105 unsigned char BaseCode; /* Base opcode */
106 unsigned char ExtCode; /* Number of ext code table */
107 void (*Emit) (const InsDesc*);/* Handler function */
110 /* An instruction table */
111 typedef struct InsTable InsTable;
113 unsigned Count; /* Number of intstructions */
114 InsDesc Ins[1]; /* Varying length */
117 /* The instruction table for the currently active CPU */
118 extern const InsTable* InsTab;
120 /* Table to build the effective opcode from a base opcode and an addressing
123 extern unsigned char EATab [9][AMI_COUNT];
125 /* Table that encodes the additional bytes for each instruction */
126 extern unsigned char ExtBytes [AMI_COUNT];
130 /*****************************************************************************/
132 /*****************************************************************************/
136 void SetCPU (cpu_t NewCPU);
140 /* Return the current CPU */
142 int FindInstruction (const char* Ident);
143 /* Check if Ident is a valid mnemonic. If so, return the index in the
144 * instruction table. If not, return -1.
147 void HandleInstruction (unsigned Index);
148 /* Handle the mnemonic with the given index */