4 /* ======================================================================== */
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5 /* ========================= LICENSING & COPYRIGHT ======================== */
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6 /* ======================================================================== */
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11 * A portable Motorola M680x0 processor emulation engine.
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12 * Copyright 1998-2007 Karl Stenerud. All rights reserved.
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14 * This code may be freely used for non-commercial purposes as long as this
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15 * copyright notice remains unaltered in the source code and any binary files
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16 * containing this code in compiled form.
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18 * All other lisencing terms must be negotiated with the author
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21 * The latest version of this code can be obtained at:
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22 * http://kstenerud.cjb.net
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25 /* ======================================================================== */
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26 /* ============================= CONFIGURATION ============================ */
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27 /* ======================================================================== */
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29 /* Import the configuration for this build */
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30 #include "m68kconf.h"
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33 /* ======================================================================== */
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34 /* ============================ GENERAL DEFINES =========================== */
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36 /* ======================================================================== */
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38 /* There are 7 levels of interrupt to the 68K.
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39 * A transition from < 7 to 7 will cause a non-maskable interrupt (NMI).
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41 #define M68K_IRQ_NONE 0
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42 #define M68K_IRQ_1 1
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43 #define M68K_IRQ_2 2
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44 #define M68K_IRQ_3 3
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45 #define M68K_IRQ_4 4
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46 #define M68K_IRQ_5 5
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47 #define M68K_IRQ_6 6
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48 #define M68K_IRQ_7 7
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51 /* Special interrupt acknowledge values.
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52 * Use these as special returns from the interrupt acknowledge callback
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53 * (specified later in this header).
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56 /* Causes an interrupt autovector (0x18 + interrupt level) to be taken.
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57 * This happens in a real 68K if VPA or AVEC is asserted during an interrupt
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58 * acknowledge cycle instead of DTACK.
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60 #define M68K_INT_ACK_AUTOVECTOR 0xffffffff
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62 /* Causes the spurious interrupt vector (0x18) to be taken
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63 * This happens in a real 68K if BERR is asserted during the interrupt
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64 * acknowledge cycle (i.e. no devices responded to the acknowledge).
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66 #define M68K_INT_ACK_SPURIOUS 0xfffffffe
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69 /* CPU types for use in m68k_set_cpu_type() */
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72 M68K_CPU_TYPE_INVALID,
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73 M68K_CPU_TYPE_68000,
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74 M68K_CPU_TYPE_68008,
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75 M68K_CPU_TYPE_68010,
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76 M68K_CPU_TYPE_68EC020,
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77 M68K_CPU_TYPE_68020,
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78 M68K_CPU_TYPE_68030, /* Supported by disassembler ONLY */
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79 M68K_CPU_TYPE_68040 /* Supported by disassembler ONLY */
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82 /* Registers used by m68k_get_reg() and m68k_set_reg() */
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85 /* Real registers */
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86 M68K_REG_D0, /* Data registers */
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94 M68K_REG_A0, /* Address registers */
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102 M68K_REG_PC, /* Program Counter */
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103 M68K_REG_SR, /* Status Register */
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104 M68K_REG_SP, /* The current Stack Pointer (located in A7) */
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105 M68K_REG_USP, /* User Stack Pointer */
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106 M68K_REG_ISP, /* Interrupt Stack Pointer */
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107 M68K_REG_MSP, /* Master Stack Pointer */
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108 M68K_REG_SFC, /* Source Function Code */
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109 M68K_REG_DFC, /* Destination Function Code */
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110 M68K_REG_VBR, /* Vector Base Register */
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111 M68K_REG_CACR, /* Cache Control Register */
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112 M68K_REG_CAAR, /* Cache Address Register */
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114 /* Assumed registers */
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115 /* These are cheat registers which emulate the 1-longword prefetch
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116 * present in the 68000 and 68010.
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118 M68K_REG_PREF_ADDR, /* Last prefetch address */
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119 M68K_REG_PREF_DATA, /* Last prefetch data */
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121 /* Convenience registers */
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122 M68K_REG_PPC, /* Previous value in the program counter */
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123 M68K_REG_IR, /* Instruction register */
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124 M68K_REG_CPU_TYPE /* Type of CPU being run */
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127 /* ======================================================================== */
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128 /* ====================== FUNCTIONS CALLED BY THE CPU ===================== */
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129 /* ======================================================================== */
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131 /* You will have to implement these functions */
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133 /* read/write functions called by the CPU to access memory.
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134 * while values used are 32 bits, only the appropriate number
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135 * of bits are relevant (i.e. in write_memory_8, only the lower 8 bits
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136 * of value should be written to memory).
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138 * NOTE: I have separated the immediate and PC-relative memory fetches
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139 * from the other memory fetches because some systems require
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140 * differentiation between PROGRAM and DATA fetches (usually
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141 * for security setups such as encryption).
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142 * This separation can either be achieved by setting
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143 * M68K_SEPARATE_READS in m68kconf.h and defining
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144 * the read functions, or by setting M68K_EMULATE_FC and
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145 * making a function code callback function.
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146 * Using the callback offers better emulation coverage
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147 * because you can also monitor whether the CPU is in SYSTEM or
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148 * USER mode, but it is also slower.
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151 /* Read from anywhere */
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152 unsigned int m68k_read_memory_8(unsigned int address);
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153 unsigned int m68k_read_memory_16(unsigned int address);
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154 unsigned int m68k_read_memory_32(unsigned int address);
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156 /* Read data immediately following the PC */
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157 unsigned int m68k_read_immediate_16(unsigned int address);
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158 unsigned int m68k_read_immediate_32(unsigned int address);
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160 /* Read data relative to the PC */
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161 unsigned int m68k_read_pcrelative_8(unsigned int address);
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162 unsigned int m68k_read_pcrelative_16(unsigned int address);
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163 unsigned int m68k_read_pcrelative_32(unsigned int address);
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165 /* Memory access for the disassembler */
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166 unsigned int m68k_read_disassembler_8 (unsigned int address);
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167 unsigned int m68k_read_disassembler_16 (unsigned int address);
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168 unsigned int m68k_read_disassembler_32 (unsigned int address);
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170 /* Write to anywhere */
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171 void m68k_write_memory_8(unsigned int address, unsigned int value);
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172 void m68k_write_memory_16(unsigned int address, unsigned int value);
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173 void m68k_write_memory_32(unsigned int address, unsigned int value);
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175 /* Special call to simulate undocumented 68k behavior when move.l with a
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176 * predecrement destination mode is executed.
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177 * To simulate real 68k behavior, first write the high word to
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178 * [address+2], and then write the low word to [address].
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180 * Enable this functionality with M68K_SIMULATE_PD_WRITES in m68kconf.h.
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182 void m68k_write_memory_32_pd(unsigned int address, unsigned int value);
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186 /* ======================================================================== */
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187 /* ============================== CALLBACKS =============================== */
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188 /* ======================================================================== */
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190 /* These functions allow you to set callbacks to the host when specific events
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191 * occur. Note that you must enable the corresponding value in m68kconf.h
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192 * in order for these to do anything useful.
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193 * Note: I have defined default callbacks which are used if you have enabled
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194 * the corresponding #define in m68kconf.h but either haven't assigned a
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195 * callback or have assigned a callback of NULL.
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198 /* Set the callback for an interrupt acknowledge.
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199 * You must enable M68K_EMULATE_INT_ACK in m68kconf.h.
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200 * The CPU will call the callback with the interrupt level being acknowledged.
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201 * The host program must return either a vector from 0x02-0xff, or one of the
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202 * special interrupt acknowledge values specified earlier in this header.
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203 * If this is not implemented, the CPU will always assume an autovectored
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204 * interrupt, and will automatically clear the interrupt request when it
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205 * services the interrupt.
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206 * Default behavior: return M68K_INT_ACK_AUTOVECTOR.
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208 void m68k_set_int_ack_callback(int (*callback)(int int_level));
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211 /* Set the callback for a breakpoint acknowledge (68010+).
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212 * You must enable M68K_EMULATE_BKPT_ACK in m68kconf.h.
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213 * The CPU will call the callback with whatever was in the data field of the
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214 * BKPT instruction for 68020+, or 0 for 68010.
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215 * Default behavior: do nothing.
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217 void m68k_set_bkpt_ack_callback(void (*callback)(unsigned int data));
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220 /* Set the callback for the RESET instruction.
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221 * You must enable M68K_EMULATE_RESET in m68kconf.h.
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222 * The CPU calls this callback every time it encounters a RESET instruction.
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223 * Default behavior: do nothing.
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225 void m68k_set_reset_instr_callback(void (*callback)(void));
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228 /* Set the callback for the CMPI.L #v, Dn instruction.
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229 * You must enable M68K_CMPILD_HAS_CALLBACK in m68kconf.h.
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230 * The CPU calls this callback every time it encounters a CMPI.L #v, Dn instruction.
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231 * Default behavior: do nothing.
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233 void m68k_set_cmpild_instr_callback(void (*callback)(unsigned int val, int reg));
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236 /* Set the callback for the RTE instruction.
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237 * You must enable M68K_RTE_HAS_CALLBACK in m68kconf.h.
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238 * The CPU calls this callback every time it encounters a RTE instruction.
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239 * Default behavior: do nothing.
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241 void m68k_set_rte_instr_callback(void (*callback)(void));
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243 /* Set the callback for the TAS instruction.
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244 * You must enable M68K_TAS_HAS_CALLBACK in m68kconf.h.
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245 * The CPU calls this callback every time it encounters a TAS instruction.
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246 * Default behavior: return 1, allow writeback.
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248 void m68k_set_tas_instr_callback(int (*callback)(void));
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252 /* Set the callback for informing of a large PC change.
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253 * You must enable M68K_MONITOR_PC in m68kconf.h.
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254 * The CPU calls this callback with the new PC value every time the PC changes
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255 * by a large value (currently set for changes by longwords).
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256 * Default behavior: do nothing.
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258 void m68k_set_pc_changed_callback(void (*callback)(unsigned int new_pc));
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261 /* Set the callback for CPU function code changes.
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262 * You must enable M68K_EMULATE_FC in m68kconf.h.
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263 * The CPU calls this callback with the function code before every memory
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264 * access to set the CPU's function code according to what kind of memory
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265 * access it is (supervisor/user, program/data and such).
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266 * Default behavior: do nothing.
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268 void m68k_set_fc_callback(void (*callback)(unsigned int new_fc));
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271 /* Set a callback for the instruction cycle of the CPU.
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272 * You must enable M68K_INSTRUCTION_HOOK in m68kconf.h.
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273 * The CPU calls this callback just before fetching the opcode in the
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274 * instruction cycle.
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275 * Default behavior: do nothing.
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277 void m68k_set_instr_hook_callback(void (*callback)(void));
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281 /* ======================================================================== */
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282 /* ====================== FUNCTIONS TO ACCESS THE CPU ===================== */
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283 /* ======================================================================== */
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285 /* Use this function to set the CPU type you want to emulate.
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286 * Currently supported types are: M68K_CPU_TYPE_68000, M68K_CPU_TYPE_68008,
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287 * M68K_CPU_TYPE_68010, M68K_CPU_TYPE_EC020, and M68K_CPU_TYPE_68020.
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289 void m68k_set_cpu_type(unsigned int cpu_type);
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291 /* Do whatever initialisations the core requires. Should be called
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292 * at least once at init time.
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294 void m68k_init(void);
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296 /* Pulse the RESET pin on the CPU.
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297 * You *MUST* reset the CPU at least once to initialize the emulation
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298 * Note: If you didn't call m68k_set_cpu_type() before resetting
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299 * the CPU for the first time, the CPU will be set to
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300 * M68K_CPU_TYPE_68000.
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302 void m68k_pulse_reset(void);
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304 /* execute num_cycles worth of instructions. returns number of cycles used */
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305 int m68k_execute(int num_cycles);
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307 /* These functions let you read/write/modify the number of cycles left to run
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308 * while m68k_execute() is running.
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309 * These are useful if the 68k accesses a memory-mapped port on another device
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310 * that requires immediate processing by another CPU.
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312 int m68k_cycles_run(void); /* Number of cycles run so far */
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313 int m68k_cycles_remaining(void); /* Number of cycles left */
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314 void m68k_modify_timeslice(int cycles); /* Modify cycles left */
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315 void m68k_end_timeslice(void); /* End timeslice now */
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317 /* Set the IPL0-IPL2 pins on the CPU (IRQ).
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318 * A transition from < 7 to 7 will cause a non-maskable interrupt (NMI).
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319 * Setting IRQ to 0 will clear an interrupt request.
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321 void m68k_set_irq(unsigned int int_level);
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324 /* Halt the CPU as if you pulsed the HALT pin. */
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325 void m68k_pulse_halt(void);
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328 /* Context switching to allow multiple CPUs */
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330 /* Get the size of the cpu context in bytes */
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331 unsigned int m68k_context_size(void);
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333 /* Get a cpu context */
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334 unsigned int m68k_get_context(void* dst);
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336 /* set the current cpu context */
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337 void m68k_set_context(void* dst);
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339 /* Register the CPU state information */
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340 void m68k_state_register(const char *type, int index);
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343 /* Peek at the internals of a CPU context. This can either be a context
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344 * retrieved using m68k_get_context() or the currently running context.
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345 * If context is NULL, the currently running CPU context will be used.
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347 unsigned int m68k_get_reg(void* context, m68k_register_t reg);
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349 /* Poke values into the internals of the currently running CPU context */
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350 void m68k_set_reg(m68k_register_t reg, unsigned int value);
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352 /* Check if an instruction is valid for the specified CPU type */
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353 unsigned int m68k_is_valid_instruction(unsigned int instruction, unsigned int cpu_type);
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355 /* Disassemble 1 instruction using the epecified CPU type at pc. Stores
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356 * disassembly in str_buff and returns the size of the instruction in bytes.
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358 unsigned int m68k_disassemble(char* str_buff, unsigned int pc, unsigned int cpu_type);
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360 /* Same as above but accepts raw opcode data directly rather than fetching
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361 * via the read/write interfaces.
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363 unsigned int m68k_disassemble_raw(char* str_buff, unsigned int pc, const unsigned char* opdata, const unsigned char* argdata, unsigned int cpu_type);
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366 /* ======================================================================== */
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367 /* ============================== MAME STUFF ============================== */
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368 /* ======================================================================== */
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370 #if M68K_COMPILE_FOR_MAME == OPT_ON
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371 #include "m68kmame.h"
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372 #endif /* M68K_COMPILE_FOR_MAME */
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375 /* ======================================================================== */
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376 /* ============================== END OF FILE ============================= */
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377 /* ======================================================================== */
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379 #endif /* M68K__HEADER */
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