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annotate code_part1/OSTC_code_asm_part1/i2c_eeprom.asm @ 198:1d98f30ed44e
minor comment translation into English
| author | heinrichsweikamp |
|---|---|
| date | Sun, 13 Feb 2011 19:46:42 +0100 |
| parents | 055977afc2f9 |
| children | dee88c962653 |
| rev | line source |
|---|---|
| 0 | 1 |
| 2 ; OSTC - diving computer code | |
| 3 ; Copyright (C) 2008 HeinrichsWeikamp GbR | |
| 4 ; This program is free software: you can redistribute it and/or modify | |
| 5 ; it under the terms of the GNU General Public License as published by | |
| 6 ; the Free Software Foundation, either version 3 of the License, or | |
| 7 ; (at your option) any later version. | |
| 8 ; This program is distributed in the hope that it will be useful, | |
| 9 ; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 10 ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 11 ; GNU General Public License for more details. | |
| 12 ; You should have received a copy of the GNU General Public License | |
| 13 ; along with this program. If not, see <http://www.gnu.org/licenses/>. | |
| 14 ; provides routines for external EEPROM via I2C | |
| 15 ; written by: Matthias Heinrichs, info@heinrichsweikamp.com | |
| 16 ; written: 10/30/05 | |
| 17 ; last updated: 08/21/06 | |
| 18 ; known bugs: | |
| 19 ; ToDo: use 2nd 32KB from external EEPROM for something | |
| 20 | |
| 21 incf_eeprom_address macro ext_ee_temp1 ; Will increase eeprom_address:2 with the 8Bit value "ext_ee_temp1" and takes | |
| 148 | 22 movlw ext_ee_temp1 ; care of bank switching at 0x8000 |
| 23 call incf_eeprom_address0 | |
| 0 | 24 endm |
| 25 | |
| 26 incf_eeprom_address0: | |
| 148 | 27 addwf eeprom_address+0,F ; increase address |
| 28 movlw d'0' | |
| 29 addwfc eeprom_address+1,F | |
| 0 | 30 |
| 148 | 31 btfss eeprom_address+1,7 ; at address 8000? |
| 32 return ; No, continue | |
| 33 | |
| 34 ; Yes, clear eeprom_address:2 | |
| 35 clrf eeprom_address+0 ; Clear eeprom address | |
| 36 clrf eeprom_address+1 | |
| 37 return ; Done. | |
| 38 | |
| 39 ;============================================================================= | |
| 40 ; Will decrease eeprom_address:2 with the 8Bit value "ext_ee_temp1" and takes | |
| 41 ; care of bank switching at 0x8000 | |
| 42 | |
| 43 decf_eeprom_address macro ext_ee_temp1 | |
| 44 movlw ext_ee_temp1 | |
| 45 call decf_eeprom_address0 | |
| 46 endm | |
| 0 | 47 |
| 48 decf_eeprom_address0: | |
| 148 | 49 subwf eeprom_address+0,F ; decrease address: do a 16-8bits substract. |
| 50 movlw d'0' | |
| 51 subwfb eeprom_address+1,F | |
| 0 | 52 |
| 148 | 53 btfss eeprom_address+1,7 ; at address 8000? |
| 54 return ; No, done. | |
| 0 | 55 |
| 148 | 56 movlw b'01111111' ; yes, reset highbyte |
| 57 movwf eeprom_address+1 | |
| 58 return ; Done. | |
| 59 | |
| 60 ;============================================================================= | |
| 0 | 61 |
| 62 write_external_eeprom: ; data in WREG | |
| 63 ; increase address eeprom_address+0:eeprom_address+1 after write | |
| 64 ; with banking after 7FFF | |
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65 #ifdef TESTING |
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66 ; When Simulating with MPLabSIM, there is no way to emulate external EEPROM... |
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67 return |
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68 #endif |
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69 |
| 0 | 70 rcall I2CWRITE ; writes WREG into EEPROM@eeprom_address |
| 71 movlw d'1' ; increase address | |
| 72 addwf eeprom_address+0,F | |
| 73 movlw d'0' | |
| 74 addwfc eeprom_address+1,F | |
| 75 bcf eeprom_overflow | |
| 76 btfss eeprom_address+1,7 ; at address 8000? | |
| 77 return ; no, return | |
| 78 | |
| 79 clrf eeprom_address+0 ; Clear eeprom address | |
| 80 clrf eeprom_address+1 | |
| 81 bsf eeprom_overflow ; and set overflow bit | |
| 82 return | |
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83
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83 |
| 0 | 84 write_external_eeprom_block: ; Writes a block of 64Byte (one page in external EEPROM without stop condition |
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85 #ifdef TESTING |
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86 ; When Simulating with MPLabSIM, there is no way to emulate external EEPROM... |
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87 return |
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88 #endif |
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89 |
| 0 | 90 btfsc eeprom_blockwrite ; Blockwrite continue? |
| 91 rcall I2CWRITE_BLOCK2 | |
| 92 btfss eeprom_blockwrite ; Blockwrite start? | |
| 93 rcall I2CWRITE_BLOCK | |
| 94 bsf eeprom_blockwrite ; After the start, do blockwriting for the next 63Bytes! | |
| 95 | |
| 96 movlw d'0' ; increase address | |
| 97 incf eeprom_address+0,F | |
| 98 addwfc eeprom_address+1,F | |
| 99 bcf eeprom_overflow | |
| 100 | |
| 101 btfss eeprom_address+1,7 ; at address 8000 | |
| 102 return ; no, return | |
| 103 | |
| 104 clrf eeprom_address+0 ; Clear eeprom address | |
| 105 clrf eeprom_address+1 | |
| 106 bsf eeprom_overflow ; and set overflow bit | |
| 107 return | |
| 108 I2CWRITE_BLOCK: | |
| 109 movwf ext_ee_temp1 ; Data byte in WREG | |
| 110 bsf SSPCON2,SEN ; Start condition | |
| 111 rcall WaitMSSP | |
| 112 movlw b'10100110' ; Bit0=0: WRITE, Bit0=1: READ | |
| 113 movwf SSPBUF ; control byte | |
| 114 rcall WaitMSSP | |
| 115 rcall I2C_WaitforACK | |
| 116 movff eeprom_address+1,SSPBUF ; High Address byte | |
| 117 rcall WaitMSSP | |
| 118 rcall I2C_WaitforACK | |
| 119 movff eeprom_address+0,SSPBUF ; Low Address byte | |
| 120 rcall WaitMSSP | |
| 121 rcall I2C_WaitforACK | |
| 122 I2CWRITE_BLOCK2: | |
| 123 movff ext_ee_temp1, SSPBUF ; Data Byte | |
| 124 rcall WaitMSSP | |
| 125 rcall I2C_WaitforACK | |
| 126 return | |
| 127 | |
| 128 | |
| 129 get_free_EEPROM_location: ; Searches 0xFD, 0xFD, 0xFE and sets Pointer to 0xFE | |
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130 |
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131 #ifdef TESTING |
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132 ; In testing mode, find 0x100 (internal EEPROM) as the first free location... |
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133 clrf eeprom_address+0 ; Not found in entire EEPROM, set to address 0 |
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134 movlw 0x1 |
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135 movwf eeprom_address+1 |
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136 return |
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137 #endif |
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138 |
| 0 | 139 clrf ext_ee_temp1 ; low address counter |
| 140 clrf ext_ee_temp2 ; high address counter | |
| 141 bcf second_FD ; clear flags | |
| 142 bcf first_FD | |
| 143 get_free_EEPROM_location3: | |
| 144 bsf SSPCON2, PEN ; Stop condition | |
| 145 rcall WaitMSSP | |
| 146 bsf SSPCON2,SEN ; Start condition | |
| 147 rcall WaitMSSP | |
| 148 movlw b'10100110' ; Bit0=0: WRITE, Bit0=1: READ | |
| 149 movwf SSPBUF ; control byte | |
| 150 rcall WaitMSSP | |
| 151 btfsc SSPCON2,ACKSTAT | |
| 152 bra get_free_EEPROM_location3 ; EEPROM NOT acknowledged, retry! | |
| 153 | |
| 154 movff ext_ee_temp2,SSPBUF ; High Address byte | |
| 155 rcall WaitMSSP | |
| 156 rcall I2C_WaitforACK | |
| 157 movff ext_ee_temp1,SSPBUF ; Low Address byte | |
| 158 rcall WaitMSSP | |
| 159 rcall I2C_WaitforACK | |
| 160 | |
| 161 bsf SSPCON2,RSEN ; Start condition | |
| 162 rcall WaitMSSP | |
| 163 movlw b'10100111' ; Bit0=0: WRITE, Bit0=1: READ | |
| 164 movwf SSPBUF ; control byte | |
| 165 rcall WaitMSSP | |
| 166 rcall I2C_WaitforACK | |
| 167 | |
| 168 get_free_EEPROM_location2: | |
| 169 bsf SSPCON2, RCEN ; Enable recieve mode | |
| 170 rcall WaitMSSP | |
| 171 btfsc first_FD | |
| 172 bra test_2nd_FD | |
| 173 bsf first_FD ; found first 0xFD? | |
| 174 movlw 0xFD | |
| 175 cpfseq SSPBUF | |
| 176 bcf first_FD ; No | |
| 177 bra get_free_EEPROM_location2c | |
| 178 | |
| 179 test_2nd_FD: | |
| 180 btfsc second_FD | |
| 181 bra test_FE | |
| 182 bsf second_FD ; found second 0xFD? | |
| 183 movlw 0xFD | |
| 184 cpfseq SSPBUF | |
| 185 bra get_free_EEPROM_location2b ;No, clear both flags | |
| 186 bra get_free_EEPROM_location2c | |
| 187 test_FE: | |
| 188 movlw 0xFE ; found the final 0xFE? | |
| 189 cpfseq SSPBUF | |
| 190 bra get_free_EEPROM_location2b ;No, clear both flags | |
| 191 movff ext_ee_temp1,eeprom_address+0 ;Yes, copy ext_ee_temp1->eeprom_address+0 and | |
| 192 movff ext_ee_temp2,eeprom_address+1 ;ext_ee_temp2->eeprom_address+1 | |
| 193 bra get_free_EEPROM_location4 ; Done. | |
| 194 | |
| 195 get_free_EEPROM_location2b: | |
| 196 bcf second_FD ; clear both flags! | |
| 197 bcf first_FD | |
| 198 get_free_EEPROM_location2c: | |
| 199 movlw d'1' ; and increase search address | |
| 200 addwf ext_ee_temp1,F | |
| 201 movlw d'0' | |
| 202 addwfc ext_ee_temp2,F | |
| 203 | |
| 42 | 204 btfsc ext_ee_temp2,7 ; 0x8000 reached? |
| 0 | 205 bra get_free_EEPROM_location3b ; yes |
| 206 | |
| 207 bsf SSPCON2, ACKEN ; no, send Ack | |
| 208 rcall WaitMSSP | |
| 209 bra get_free_EEPROM_location2 ; and continue search | |
| 210 get_free_EEPROM_location3b: | |
| 211 clrf eeprom_address+0 ; Not found in entire EEPROM, set to address 0 | |
| 212 clrf eeprom_address+1 | |
| 213 get_free_EEPROM_location4: | |
| 214 bsf SSPCON2, PEN ; Stop | |
| 215 rcall WaitMSSP | |
| 216 | |
| 217 bcf second_FD ; clear flags | |
| 218 bcf first_FD | |
| 219 return ; return | |
| 220 | |
| 221 | |
| 222 I2CREAD: | |
| 223 bsf SSPCON2, PEN ; Stop | |
| 224 rcall WaitMSSP | |
| 225 bsf SSPCON2,SEN ; Start condition | |
| 226 rcall WaitMSSP | |
| 227 movlw b'10100110' ; Bit0=0: WRITE, Bit0=1: READ | |
| 228 movwf SSPBUF ; control byte | |
| 229 rcall WaitMSSP | |
| 230 btfsc SSPCON2,ACKSTAT | |
| 231 bra I2CREAD ; EEPROM NOT acknowledged, retry! | |
| 232 movff eeprom_address+1,SSPBUF ; High Address byte | |
| 233 rcall WaitMSSP | |
| 234 rcall I2C_WaitforACK | |
| 235 movff eeprom_address+0,SSPBUF ; Low Address byte | |
| 236 rcall WaitMSSP | |
| 237 rcall I2C_WaitforACK | |
| 238 | |
| 239 bsf SSPCON2,RSEN ; Start condition | |
| 240 rcall WaitMSSP | |
| 241 movlw b'10100111' ; Bit0=0: WRITE, Bit0=1: READ | |
| 242 movwf SSPBUF ; control byte | |
| 243 rcall WaitMSSP | |
| 244 rcall I2C_WaitforACK | |
| 245 | |
| 246 bsf SSPCON2, RCEN ; Enable recieve mode | |
| 247 rcall WaitMSSP | |
| 248 movf SSPBUF,W ; copy read byte into WREG | |
| 249 bsf SSPCON2, PEN ; Stop | |
| 250 rcall WaitMSSP | |
| 251 return | |
| 252 | |
| 253 I2CREAD2: ; same as I2CREAD but with automatic address increase | |
| 254 rcall I2CREAD | |
| 255 movlw d'1' | |
| 256 addwf eeprom_address+0,F | |
| 257 movlw d'0' | |
| 258 addwfc eeprom_address+1,F | |
| 259 bcf eeprom_overflow | |
| 260 btfss eeprom_address+1,7 ; at 0x8000? | |
| 261 return ; no, return | |
| 262 | |
| 263 clrf eeprom_address+0 ; Yes, clear address | |
| 264 clrf eeprom_address+1 | |
| 265 bsf eeprom_overflow ; and set overflow bit | |
| 266 return | |
| 267 | |
| 268 I2CWRITE: | |
| 269 movwf ext_ee_temp1 ; Data byte | |
| 270 bsf SSPCON2,SEN ; Start condition | |
| 271 rcall WaitMSSP | |
| 272 movlw b'10100110' ; Bit0=0: WRITE, Bit0=1: READ | |
| 273 movwf SSPBUF ; control byte | |
| 274 rcall WaitMSSP | |
| 275 rcall I2C_WaitforACK | |
| 276 movff eeprom_address+1,SSPBUF ; High Address byte | |
| 277 rcall WaitMSSP | |
| 278 rcall I2C_WaitforACK | |
| 279 movff eeprom_address+0,SSPBUF ; Low Address byte | |
| 280 rcall WaitMSSP | |
| 281 rcall I2C_WaitforACK | |
| 282 movff ext_ee_temp1, SSPBUF ; Data Byte | |
| 283 rcall WaitMSSP | |
| 284 rcall I2C_WaitforACK | |
| 285 bsf SSPCON2,PEN ; Stop condition | |
| 286 rcall WaitMSSP | |
| 287 WAITMS d'6' ; Write delay | |
| 288 return | |
| 289 | |
| 290 I2C_WaitforACK: | |
| 291 btfsc SSPCON2,ACKSTAT ; checks for ACK bit from slave | |
| 292 rcall I2CFail | |
| 293 return | |
| 294 | |
| 295 I2CFail: | |
| 296 ostc_debug 'M' ; Sends debug-information to screen if debugmode active | |
| 21 | 297 bsf LED_red |
| 0 | 298 rcall I2CReset ; I2C Reset |
| 299 bcf PIR1,SSPIF | |
| 300 clrf i2c_temp | |
| 301 return | |
| 302 | |
| 303 WaitMSSP: | |
| 304 decfsz i2c_temp,F ; check for timeout during I2C action | |
| 305 bra WaitMSSP2 | |
| 306 bra I2CFail ; timeout occured | |
| 307 WaitMSSP2: | |
| 308 btfss PIR1,SSPIF | |
| 309 bra WaitMSSP | |
| 310 clrf i2c_temp | |
| 311 bcf PIR1,SSPIF | |
| 312 return | |
| 313 | |
| 314 I2CReset: ; Something went wrong (Slave holds SDA low?) | |
| 315 clrf SSPCON1 ; wake-up slave and reset entire module | |
| 316 ostc_debug 'N' ; Sends debug-information to screen if debugmode active | |
| 317 clrf SSPCON2 | |
| 318 clrf SSPSTAT | |
| 319 bcf TRISC,3 ; SCL OUTPUT | |
| 320 bsf TRISC,4 ; SDA Input | |
| 321 bcf PORTC,3 | |
| 322 movlw d'9' | |
| 323 movwf i2c_temp ; clock-out 9 clock cycles manually | |
| 324 I2CReset_1: | |
| 325 bsf PORTC,3 ; SCL=1 | |
| 326 nop | |
| 327 btfsc PORTC,4 ; SDA=1? | |
| 328 bra I2CReset_2 ; =1, SDA has been released from slave | |
| 329 bcf PORTC,3 ; SCL=0 | |
| 330 bcf PORTC,3 | |
| 331 decfsz i2c_temp,F | |
| 332 bra I2CReset_1 ; check for nine clock cycles | |
| 333 I2CReset_2: | |
| 334 bsf TRISC,3 ; SCL Input | |
| 335 clrf SSPCON1 ; set I²C Mode | |
| 336 WAITMS d'10' ; Reset-Timeout for I2C devices | |
| 337 movlw b'00000000' | |
| 338 movwf SSPSTAT | |
| 339 movlw b'00101000' | |
| 340 movwf SSPCON1 | |
| 341 movlw b'00000000' | |
| 342 movwf SSPCON2 | |
| 343 movlw d'8' ; 400kHz I2C clock @ 16MHz Fcy | |
| 344 movwf SSPADD | |
| 21 | 345 bcf LED_red |
| 0 | 346 ostc_debug 'O' ; Sends debug-information to screen if debugmode active |
| 347 return | |
| 53 | 348 |
| 349 ;I2C_TX: | |
| 350 ; movwf i2c_temp2 ; Data byte | |
| 351 ; bsf SSPCON2,SEN ; Start condition | |
| 352 ; rcall WaitMSSP | |
| 353 ; movlw b'10010000' ; Bit0=0: WRITE, Bit0=1: READ | |
| 354 ; movwf SSPBUF ; control byte | |
| 355 ; rcall WaitMSSP | |
| 356 ; rcall I2C_WaitforACK | |
| 357 ; movff i2c_temp2, SSPBUF ; Data Byte | |
| 358 ; rcall WaitMSSP | |
| 359 ; rcall I2C_WaitforACK | |
| 360 ; bsf SSPCON2,PEN ; Stop condition | |
| 361 ; rcall WaitMSSP | |
| 362 ; return | |
| 363 ;I2C_RX: | |
| 364 ; bcf PIR1,SSPIF | |
| 365 ; bsf SSPCON2,SEN ; Start condition | |
| 366 ; rcall WaitMSSP | |
| 367 ; movlw b'10010001' ; Bit0=0: WRITE, Bit0=1: READ | |
| 368 ; movwf SSPBUF ; control byte | |
| 369 ; rcall WaitMSSP | |
| 370 ; rcall I2C_WaitforACK | |
| 371 ; bsf SSPCON2, RCEN ; Enable recieve mode | |
| 372 ; rcall WaitMSSP | |
| 373 ; movff SSPBUF,i2c_temp2 ; Data Byte | |
| 374 ; bsf SSPCON2,ACKEN ; Master acknowlegde | |
| 375 ; rcall WaitMSSP | |
| 376 ; bsf SSPCON2,PEN ; Stop condition | |
| 377 ; rcall WaitMSSP | |
| 378 ; return |