Mercurial > repos > simple16
annotate src/cpu.c @ 28:c677507682e3
Untested controller implementation
author | Michael Pavone <pavone@retrodev.com> |
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date | Sun, 03 Apr 2016 00:33:54 -0700 |
parents | 083347ccd508 |
children | 5683d9ba9acc |
rev | line source |
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0
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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1 #include <stdint.h> |
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2 #include <stdlib.h> |
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3 #include <string.h> |
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4 #include <stdio.h> |
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5 #include "cpu.h" |
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6 |
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7 enum { |
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8 EXCEPTION_INTERRUPT_0, |
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9 EXCEPTION_INTERRUPT_1, |
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10 EXCEPTION_UNALIGNED_READ, |
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11 EXCEPTION_INVALID_INSTRUCTION |
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12 }; |
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13 |
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14 enum { |
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15 STATE_NEED_FETCH, |
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16 STATE_NORMAL, |
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17 STATE_EXCEPTION_START |
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18 }; |
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19 |
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20 #define STATUS_INT0_ENABLE 1 |
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21 #define STATUS_INT1_ENABLE 2 |
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22 #define FLAG_Z 4 |
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23 #define FLAG_C 8 |
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24 #define FLAG_N 16 |
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25 |
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26 cpu* alloc_cpu(uint32_t clock_divider, uint32_t num_regions, memory_region *regions) |
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27 { |
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28 size_t alloc_size = sizeof(cpu) + sizeof(memory_region) * num_regions; |
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29 cpu *context = malloc(alloc_size); |
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30 memset(context, 0, alloc_size); |
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31 context->clock_inc = clock_divider; |
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32 context->num_mem_regions = num_regions; |
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33 memcpy(context->mem_regions, regions, num_regions*sizeof(memory_region)); |
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34 |
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35 return context; |
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36 } |
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37 |
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38 uint16_t cpu_read_16(cpu *context, uint16_t address) |
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39 { |
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40 context->cycles += context->clock_inc; |
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41 if (address & 1) { |
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42 context->exception = EXCEPTION_UNALIGNED_READ; |
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43 context->state = STATE_EXCEPTION_START; |
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44 return 0xFFFF; |
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45 } |
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46 memory_region *cur = context->mem_regions; |
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47 for (memory_region *end = cur + context->num_mem_regions; cur < end; cur++) |
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48 { |
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49 if (address >= cur->start && address <= cur->end && (cur->flags & MEM_READ)) { |
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50 return cur->base[address - cur->start] << 8 | cur->base[address - cur->start + 1]; |
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51 } |
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52 } |
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53 return 0xFFFF; |
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54 } |
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55 |
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56 uint8_t cpu_read_8(cpu *context, uint16_t address) |
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57 { |
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58 context->cycles += context->clock_inc; |
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59 memory_region *cur = context->mem_regions; |
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60 for (memory_region *end = cur + context->num_mem_regions; cur < end; cur++) |
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61 { |
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62 if (address >= cur->start && address <= cur->end && (cur->flags & MEM_READ)) { |
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63 return cur->base[address - cur->start]; |
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64 } |
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65 } |
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66 return 0xFF; |
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67 } |
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68 |
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69 void cpu_write_16(cpu *context, uint16_t address, uint16_t value) |
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70 { |
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71 context->cycles += context->clock_inc; |
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72 if (address & 1) { |
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73 context->exception = EXCEPTION_UNALIGNED_READ; |
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74 context->state = STATE_EXCEPTION_START; |
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75 return; |
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76 } |
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77 memory_region *cur = context->mem_regions; |
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78 for (memory_region *end = cur + context->num_mem_regions; cur < end; cur++) |
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79 { |
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80 if (address >= cur->start && address <= cur->end && (cur->flags & MEM_WRITE)) { |
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81 cur->base[address - cur->start] = value >> 8; |
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82 cur->base[address - cur->start + 1] = value; |
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83 break; |
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84 } |
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85 } |
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86 } |
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87 |
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88 void cpu_write_8(cpu *context, uint16_t address, uint8_t value) |
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89 { |
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90 context->cycles += context->clock_inc; |
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91 memory_region *cur = context->mem_regions; |
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92 for (memory_region *end = cur + context->num_mem_regions; cur < end; cur++) |
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93 { |
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94 if (address >= cur->start && address <= cur->end && (cur->flags & MEM_WRITE)) { |
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95 cur->base[address - cur->start] = value; |
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96 break; |
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97 } |
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98 } |
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99 } |
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100 |
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101 uint16_t cpu_read_port(cpu *context, uint8_t port) |
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102 { |
20 | 103 context->cycles += context->clock_inc; |
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104 port &= 0xF; |
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105 if (context->port_handlers[port].read) { |
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106 return context->port_handlers[port].read(context, port); |
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107 } |
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108 return 0xFFFF; |
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109 } |
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110 |
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111 void cpu_write_port(cpu *context, uint8_t port, uint16_t value) |
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112 { |
20 | 113 context->cycles += context->clock_inc; |
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114 port &= 0xF; |
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115 if (context->port_handlers[port].write) { |
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116 context->port_handlers[port].write(context, port, value); |
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117 } |
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118 } |
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119 |
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120 void fetch_instruction(cpu *context) |
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121 { |
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122 context->prefetch = cpu_read_16(context, context->regs[REG_PC]); |
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123 context->regs[REG_PC] += 2; |
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124 context->state = STATE_NORMAL; |
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125 } |
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126 |
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127 void vector_fetch(cpu *context) |
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128 { |
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129 context->exception_pc = context->regs[REG_PC] - 2; |
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130 context->exception_sr = context->regs[REG_SR]; |
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131 context->regs[REG_SR] &= ~(STATUS_INT0_ENABLE | STATUS_INT1_ENABLE); |
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132 context->regs[REG_PC] = cpu_read_16(context, context->vector_base + context->exception * 2); |
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133 context->state = STATE_NEED_FETCH; |
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134 } |
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135 |
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136 uint16_t sign_extend(uint16_t val) |
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137 { |
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138 if (val & 0x80) { |
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139 return val | 0xFF00; |
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140 } |
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141 return val; |
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142 } |
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143 |
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144 void update_flags_arith(cpu *context, uint32_t result) |
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145 { |
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146 context->regs[REG_SR] &= ~(FLAG_N|FLAG_C|FLAG_Z); |
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147 if (!(result & 0xFFFF)) { |
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148 context->regs[REG_SR] |= FLAG_Z; |
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149 } |
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150 if (result & 0x8000) { |
0
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151 context->regs[REG_SR] |= FLAG_N; |
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152 } |
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153 if (result & 0x10000) { |
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154 context->regs[REG_SR] |= FLAG_C; |
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155 } |
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156 } |
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157 |
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158 void update_flags_bitwise(cpu *context, uint32_t result) |
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159 { |
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160 context->regs[REG_SR] &= ~(FLAG_N|FLAG_Z); |
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161 if (!(result & 0xFFFF)) { |
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162 context->regs[REG_SR] |= FLAG_Z; |
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163 } |
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164 if (result &= 0x8000) { |
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165 context->regs[REG_SR] |= FLAG_N; |
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166 } |
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167 } |
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168 |
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169 void run_bcc(cpu *context, uint8_t condition, uint8_t a, uint8_t b) |
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170 { |
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171 |
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172 uint8_t doit = 0; |
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173 switch (condition) |
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174 { |
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175 case COND_ALWAYS: |
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176 doit = 1; |
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177 break; |
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178 case COND_NEVER: |
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179 break; |
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180 case COND_ZERO: |
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181 doit = context->regs[REG_SR] & FLAG_Z; |
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182 break; |
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183 case COND_NZERO: |
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184 doit = !(context->regs[REG_SR] & FLAG_Z); |
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185 break; |
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186 case COND_NEG: |
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187 doit = context->regs[REG_SR] & FLAG_N; |
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188 break; |
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189 case COND_POS: |
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190 doit = !(context->regs[REG_SR] & FLAG_N); |
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191 break; |
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192 case COND_CARRY: |
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193 doit = context->regs[REG_SR] & FLAG_C; |
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194 break; |
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195 case COND_NCARRY: |
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196 doit = !(context->regs[REG_SR] & FLAG_C); |
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197 break; |
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198 case COND_GREATER: |
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199 //not zero and not carry |
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200 doit = !(context->regs[REG_SR] & FLAG_Z) && !(context->regs[REG_SR] & FLAG_C); |
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201 break; |
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202 case COND_LEQ: |
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203 //zero or carry |
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204 doit = (context->regs[REG_SR] & FLAG_Z) || (context->regs[REG_SR] & FLAG_C); |
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205 break; |
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206 default: |
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207 context->exception = EXCEPTION_INVALID_INSTRUCTION; |
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208 context->state = STATE_EXCEPTION_START; |
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209 return; |
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210 } |
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211 |
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212 if (doit) { |
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213 context->regs[REG_PC] += sign_extend(a << 4 | b) * 2; |
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214 context->state = STATE_NEED_FETCH; |
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215 } |
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216 } |
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217 |
2
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Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi.
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218 uint16_t format_immediate(uint16_t val) |
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219 { |
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220 if (val & 8) { |
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221 val |= 0xFFF0; |
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222 } |
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223 if (!val) { |
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224 val = 8; |
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225 } |
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226 return val; |
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227 } |
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228 |
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229 void run_single_reg(cpu *context, uint8_t dst, uint8_t op) |
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230 { |
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231 switch(op) |
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232 { |
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233 case RETI: |
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234 context->regs[dst] = context->exception_ur; |
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235 context->regs[REG_PC] = context->exception_pc; |
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236 context->regs[REG_SR] = context->exception_sr; |
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237 context->state = STATE_NEED_FETCH; |
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238 return; |
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239 case TRAP: |
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240 context->state = STATE_EXCEPTION_START; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
|
241 context->exception = context->regs[dst]; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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242 return; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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243 case TRAPI: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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244 context->state = STATE_EXCEPTION_START; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
|
245 context->exception = dst; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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246 return; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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247 case GETEPC: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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changeset
|
248 context->regs[dst] = context->exception_pc; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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249 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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250 case SETEPC: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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251 context->exception_pc = context->regs[dst]; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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252 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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253 case GETESR: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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changeset
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254 context->regs[dst] = context->exception_sr; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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255 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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256 case SETESR: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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257 context->exception_sr = context->regs[dst]; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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changeset
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258 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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259 case GETEUR: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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260 context->regs[dst] = context->exception_ur; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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261 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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262 case SETEUR: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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changeset
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263 context->exception_ur = context->regs[dst]; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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changeset
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264 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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265 case GETENUM: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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changeset
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266 context->regs[dst] = context->exception; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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changeset
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267 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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268 case SETENUM: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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changeset
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269 context->exception = context->regs[dst]; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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270 break; |
25
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
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parents:
20
diff
changeset
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271 case GETVBR: |
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Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
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parents:
20
diff
changeset
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272 context->regs[dst] = context->vector_base; |
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Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
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parents:
20
diff
changeset
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273 break; |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
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parents:
20
diff
changeset
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274 case SETVBR: |
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Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
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parents:
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diff
changeset
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275 context->vector_base = context->regs[dst]; |
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parents:
20
diff
changeset
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276 break; |
0
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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277 default: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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changeset
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278 context->state = STATE_EXCEPTION_START; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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279 context->exception = EXCEPTION_INVALID_INSTRUCTION; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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changeset
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280 return; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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281 } |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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282 if (dst == REG_PC) { |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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283 context->state = STATE_NEED_FETCH; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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284 } |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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285 } |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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286 |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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287 void run_single_source(cpu *context, uint8_t dst, uint8_t a, uint8_t op) |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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288 { |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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289 uint32_t tmp; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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290 uint8_t shift; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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291 switch(op) |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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292 { |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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293 case MOVE: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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294 context->regs[dst] = context->regs[a]; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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changeset
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295 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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296 case NEG: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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297 tmp = -context->regs[a]; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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298 context->regs[dst] = tmp; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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299 update_flags_arith(context, tmp); |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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300 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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301 case NOT: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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302 context->regs[dst] = ~context->regs[a]; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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303 update_flags_bitwise(context, context->regs[dst]); |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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304 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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305 case CMP: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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306 tmp = context->regs[dst] - context->regs[a]; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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307 update_flags_arith(context, tmp); |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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308 return; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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309 case CALL: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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310 context->regs[dst] = context->regs[REG_PC] - 2; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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311 context->regs[REG_PC] = context->regs[a]; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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312 context->state = STATE_NEED_FETCH; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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313 return; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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314 case SWAP: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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315 tmp = context->regs[dst]; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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316 context->regs[dst] = context->regs[a]; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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317 context->regs[a] = tmp; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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318 if (a == REG_PC) { |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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319 context->state = STATE_NEED_FETCH; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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320 return; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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321 } |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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322 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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323 case IN: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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324 context->regs[dst] = cpu_read_port(context, context->regs[a]); |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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325 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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326 case OUT: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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327 cpu_write_port(context, context->regs[a], context->regs[dst]); |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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328 return; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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329 case INI: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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330 context->regs[dst] = cpu_read_port(context, a); |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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331 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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changeset
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332 case OUTI: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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333 cpu_write_port(context, a, context->regs[dst]); |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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334 return; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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335 case ADDI: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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336 tmp = context->regs[dst] + format_immediate(a); |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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337 context->regs[dst] = tmp; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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338 update_flags_arith(context, tmp); |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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339 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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340 case ANDI: |
2
6204c81e2933
Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi.
Michael Pavone <pavone@retrodev.com>
parents:
0
diff
changeset
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341 context->regs[dst] = context->regs[dst] & format_immediate(a); |
0
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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342 update_flags_bitwise(context, context->regs[dst]); |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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343 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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344 case ORI: |
2
6204c81e2933
Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi.
Michael Pavone <pavone@retrodev.com>
parents:
0
diff
changeset
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345 context->regs[dst] = context->regs[dst] | format_immediate(a); |
0
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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346 update_flags_bitwise(context, context->regs[dst]); |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
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347 break; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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348 case LSI: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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349 shift = a & 7; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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350 if (!shift) { |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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351 shift = 8; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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352 } |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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353 if (a & 8) { |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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354 tmp = context->regs[dst] >> shift; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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355 tmp |= (context->regs[dst] >> (shift - 1)) << 16 & 0x10000; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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356 } else { |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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357 tmp = context->regs[dst] << (a & 7); |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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358 } |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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359 context->regs[dst] = tmp; |
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Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
360 update_flags_arith(context, tmp); |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
|
361 break; |
2
6204c81e2933
Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi.
Michael Pavone <pavone@retrodev.com>
parents:
0
diff
changeset
|
362 case CMPI: |
6204c81e2933
Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi.
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parents:
0
diff
changeset
|
363 tmp = a; |
6204c81e2933
Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi.
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parents:
0
diff
changeset
|
364 if (a & 8) { |
6204c81e2933
Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi.
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parents:
0
diff
changeset
|
365 a |= 0xFFF0; |
0
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
|
366 } |
2
6204c81e2933
Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi.
Michael Pavone <pavone@retrodev.com>
parents:
0
diff
changeset
|
367 tmp = context->regs[dst] - a; |
0
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
|
368 update_flags_arith(context, tmp); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
|
369 break; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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370 case SINGLE_REG: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
371 run_single_reg(context, dst, a); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
372 return; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
373 } |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
374 if (dst == REG_PC) { |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
|
375 context->state = STATE_NEED_FETCH; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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376 } |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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377 } |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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378 |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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379 void run_instruction(cpu *context) |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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380 { |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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381 uint16_t instruction = context->prefetch; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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382 fetch_instruction(context); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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383 uint8_t dst = instruction >> 12; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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384 uint8_t a = instruction >> 8 & 0xF; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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385 uint8_t b = instruction >> 4 & 0xF; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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386 uint8_t op = instruction & 0xF; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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387 uint32_t tmp; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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388 switch (op) |
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Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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389 { |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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390 case LDIM: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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391 context->regs[dst] = sign_extend(a << 4 | b); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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392 break; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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393 case LDIMH: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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394 context->regs[dst] &= 0xFF; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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395 context->regs[dst] |= a << 12 | b << 8; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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396 break; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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397 case LD8: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
398 context->regs[dst] = cpu_read_8(context, context->regs[a] + context->regs[b]); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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399 break; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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400 case LD16: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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401 context->regs[dst] = cpu_read_16(context, context->regs[a] + context->regs[b]); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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402 break; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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403 case STR8: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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404 cpu_write_8(context, context->regs[a] + context->regs[b], context->regs[dst]); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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405 return; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
406 case STR16: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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407 cpu_write_16(context, context->regs[a] + context->regs[b], context->regs[dst]); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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408 return; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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409 case ADD: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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410 tmp = context->regs[a] + context->regs[b]; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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411 context->regs[dst] = tmp; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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412 update_flags_arith(context, tmp); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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413 break; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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414 case ADC: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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415 tmp = context->regs[a] + context->regs[b] + (context->regs[REG_SR] & FLAG_C ? 1 : 0); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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416 context->regs[dst] = tmp; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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417 update_flags_arith(context, tmp); |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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418 break; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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419 case AND: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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420 context->regs[dst] = context->regs[a] & context->regs[b]; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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421 update_flags_bitwise(context, context->regs[dst]); |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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422 break; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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423 case OR: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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424 context->regs[dst] = context->regs[a] | context->regs[b]; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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425 update_flags_bitwise(context, context->regs[dst]); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
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426 break; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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427 case XOR: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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428 context->regs[dst] = context->regs[a] ^ context->regs[b]; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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429 update_flags_bitwise(context, context->regs[dst]); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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430 break; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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431 case LSL: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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432 tmp = context->regs[a] << context->regs[b]; |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
|
433 context->regs[dst] = tmp; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
|
434 update_flags_arith(context, tmp); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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435 break; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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436 case LSR: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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437 tmp = context->regs[a] >> context->regs[b]; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
438 tmp |= (context->regs[a] >> (context->regs[b] - 1)) << 16 & 0x10000; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
439 context->regs[dst] = tmp; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
440 update_flags_arith(context, tmp); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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441 break; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
442 case ASR: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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443 tmp = context->regs[a]; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
444 if (tmp & 0x8000) { |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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445 tmp |= 0xFFFF0000; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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446 } |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
447 tmp = tmp >> context->regs[b] & 0xFFFF; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
448 tmp |= (context->regs[a] >> (context->regs[b] - 1)) << 16 & 0x10000; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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449 context->regs[dst] = tmp; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
450 update_flags_arith(context, tmp); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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451 break; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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452 case BCC: |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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453 run_bcc(context, dst, a, b); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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454 return; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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455 case SINGLE_SOURCE: |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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456 run_single_source(context, dst, a, b); |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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457 return; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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458 } |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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459 if (dst == REG_PC) { |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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460 context->state = STATE_NEED_FETCH; |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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461 } |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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462 } |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
463 |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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464 void run_cpu(cpu *context, uint32_t target_cycle) |
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Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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465 { |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
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466 while (context->cycles < target_cycle) |
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Initial commit. CPU working well enough for simple hello world program.
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parents:
diff
changeset
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467 { |
25
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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468 context->current_target = target_cycle; |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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469 context->pending_interrupts = get_current_interrupts(context); |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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470 uint32_t int_cycle = next_interrupt_cycle(context, (~context->pending_interrupts) & 0x3); |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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471 if (int_cycle < context->current_target) { |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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472 context->current_target = int_cycle; |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
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473 } |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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474 while (context->cycles < context->current_target) |
0
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
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475 { |
25
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
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changeset
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476 switch (context->state) |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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477 { |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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478 case STATE_NEED_FETCH: |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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479 fetch_instruction(context); |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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480 break; |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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481 case STATE_NORMAL: |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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482 if (context->regs[REG_SR] & context->pending_interrupts) { |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
|
483 context->state = STATE_EXCEPTION_START; |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
|
484 context->exception = context->pending_interrupts & 1 ? EXCEPTION_INTERRUPT_0 : EXCEPTION_INTERRUPT_1; |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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485 context->pending_interrupts &= ~(1 << context->exception); |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
|
486 ack_interrupt(context, context->exception); |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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487 } else { |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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488 run_instruction(context); |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
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489 } |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
|
490 break; |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
|
491 case STATE_EXCEPTION_START: |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
|
492 vector_fetch(context); |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
|
493 break; |
fb14515266f4
Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file
Michael Pavone <pavone@retrodev.com>
parents:
20
diff
changeset
|
494 } |
0
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
495 } |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
496 } |
7e44f7d5810b
Initial commit. CPU working well enough for simple hello world program.
Michael Pavone <pavone@retrodev.com>
parents:
diff
changeset
|
497 } |