ATMega chip full datasheet - UCSD Department of Physics

More documents

Recommendations

Info

ATmega48A/PA/88A/PA/168A/PA/328/PCaution: An interrupt between step 5 and step 6 will make the write cycle fail, since theEEPROM Master Write Enable will time-out. If an interrupt routine accessing the EEPROM isinterrupting another EEPROM access, the EEAR or EEDR Register will be modified, causing theinterrupted EEPROM access to fail. It is recommended to have the Global Interrupt Flag clearedduring all the steps to avoid these problems.When the write access time has elapsed, the EEPE bit is cleared by hardware. The user softwarecan poll this bit and wait for a zero before writing the next byte. When EEPE has been set,the CPU is halted for two cycles before the next instruction is executed.• Bit 0 – EERE: EEPROM Read EnableThe EEPROM Read Enable Signal EERE is the read strobe to the EEPROM. When the correctaddress is set up in the EEAR Register, the EERE bit must be written to a logic one to trigger theEEPROM read. The EEPROM read access takes one instruction, and the requested data isavailable immediately. When the EEPROM is read, the CPU is halted for four cycles before thenext instruction is executed.The user should poll the EEPE bit before starting the read operation. If a write operation is inprogress, it is neither possible to read the EEPROM, nor to change the EEAR Register.The calibrated Oscillator is used to time the EEPROM accesses. Table 8-2 lists the typical programmingtime for EEPROM access from the CPU.Table 8-2.EEPROM Programming TimeSymbol Number of Calibrated RC Oscillator Cycles Typ Programming TimeEEPROM write(from CPU)26,368 3.3msThe following code examples show one assembly and one C function for writing to theEEPROM. The examples assume that interrupts are controlled (e.g. by disabling interrupts globally)so that no interrupts will occur during execution of these functions. The examples alsoassume that no Flash Boot Loader is present in the software. If such code is present, theEEPROM write function must also wait for any ongoing SPM command to finish.8271D–AVR–05/1124
ATmega48A/PA/88A/PA/168A/PA/328/PAssembly Code ExampleEEPROM_write:; Wait for completion of previous writesbic EECR,EEPErjmp EEPROM_write; Set up address (r18:r17) in address registerout EEARH, r18out EEARL, r17; Write data (r16) to Data Registerout EEDR,r16; Write logical one to EEMPEsbi EECR,EEMPE; Start eeprom write by setting EEPEsbi EECR,EEPEretC Code Examplevoid EEPROM_write(unsigned int uiAddress, unsigned char ucData){/* Wait for completion of previous write */while(EECR & (1
Page 1 and 2: Features• High Performance, Low P
Page 3: ATmega48A/PA/88A/PA/168A/PA/328/P1.
Page 7 and 8: ATmega48A/PA/88A/PA/168A/PA/328/PTa
Page 9 and 10: ATmega48A/PA/88A/PA/168A/PA/328/P7.
Page 11 and 12: ATmega48A/PA/88A/PA/168A/PA/328/Psp
Page 23: ATmega48A/PA/88A/PA/168A/PA/328/P
Page 29 and 30: ATmega48A/PA/88A/PA/168A/PA/328/Pse
Page 37 and 38: ATmega48A/PA/88A/PA/168A/PA/328/PWh
Page 39 and 40: ATmega48A/PA/88A/PA/168A/PA/328/PTh
Page 41 and 42: ATmega48A/PA/88A/PA/168A/PA/328/P10
Page 47 and 48: ATmega48A/PA/88A/PA/168A/PA/328/P
Page 49 and 50: ATmega48A/PA/88A/PA/168A/PA/328/PFi
Page 51 and 52: ATmega48A/PA/88A/PA/168A/PA/328/PFi
Page 53 and 54: ATmega48A/PA/88A/PA/168A/PA/328/Pmo
Page 55 and 56: ATmega48A/PA/88A/PA/168A/PA/328/PTh
Page 57 and 58: ATmega48A/PA/88A/PA/168A/PA/328/PWa
Page 63 and 64: ATmega48A/PA/88A/PA/168A/PA/328/PWh
Page 67 and 68: ATmega48A/PA/88A/PA/168A/PA/328/PAd
Page 69 and 70: ATmega48A/PA/88A/PA/168A/PA/328/P0x
Page 71 and 72: ATmega48A/PA/88A/PA/168A/PA/328/Pa.
Page 75 and 76:
ATmega48A/PA/88A/PA/168A/PA/328/P13
Page 77 and 78:
Page 79 and 80:
ATmega48A/PA/88A/PA/168A/PA/328/PIf
Page 81 and 82:
ATmega48A/PA/88A/PA/168A/PA/328/PAs
Page 83 and 84:
ATmega48A/PA/88A/PA/168A/PA/328/PTa
Page 85 and 86:
ATmega48A/PA/88A/PA/168A/PA/328/PAS
Page 87 and 88:
Page 89 and 90:
ATmega48A/PA/88A/PA/168A/PA/328/P
Page 91 and 92:
ATmega48A/PA/88A/PA/168A/PA/328/PTh
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
ATmega48A/PA/88A/PA/168A/PA/328/PFi
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
ATmega48A/PA/88A/PA/168A/PA/328/Pth
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
ATmega48A/PA/88A/PA/168A/PA/328/Ppu
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
ATmega48A/PA/88A/PA/168A/PA/328/Pti
Page 125 and 126:
ATmega48A/PA/88A/PA/168A/PA/328/Ppr
Page 127 and 128:
ATmega48A/PA/88A/PA/168A/PA/328/Pno
Page 129 and 130:
Page 131 and 132:
ATmega48A/PA/88A/PA/168A/PA/328/P0x
Page 133 and 134:
ATmega48A/PA/88A/PA/168A/PA/328/Pth
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
ATmega48A/PA/88A/PA/168A/PA/328/PWh
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
ATmega48A/PA/88A/PA/168A/PA/328/PIn
Page 155 and 156:
ATmega48A/PA/88A/PA/168A/PA/328/Pou
Page 157 and 158:
Page 159 and 160:
ATmega48A/PA/88A/PA/168A/PA/328/P(R
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
ATmega48A/PA/88A/PA/168A/PA/328/PA
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
ATmega48A/PA/88A/PA/168A/PA/328/Pta
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
ATmega48A/PA/88A/PA/168A/PA/328/Pbe
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217 and 218:
Page 219 and 220:
Page 221 and 222:
ATmega48A/PA/88A/PA/168A/PA/328/Pma
Page 223 and 224:
Page 225 and 226:
Page 227 and 228:
Page 229 and 230:
Page 231 and 232:
ATmega48A/PA/88A/PA/168A/PA/328/PAf
Page 233 and 234:
Page 235 and 236:
Page 237 and 238:
Page 239 and 240:
ATmega48A/PA/88A/PA/168A/PA/328/PTo
Page 241 and 242:
Page 243 and 244:
Page 245 and 246:
Page 247 and 248:
Page 249 and 250:
Page 251 and 252:
Page 253 and 254:
Page 255 and 256:
ATmega48A/PA/88A/PA/168A/PA/328/PIf
Page 257 and 258:
Page 259 and 260:
Page 261 and 262:
Page 263 and 264:
Page 265 and 266:
Page 267 and 268:
Page 269 and 270:
Page 271 and 272:
Page 273 and 274:
Page 275 and 276:
Page 277 and 278:
ATmega48A/PA/88A/PA/168A/PA/328/Psb
Page 279 and 280:
ATmega48A/PA/88A/PA/168A/PA/328/PPa
Page 281 and 282:
Page 283 and 284:
Page 285 and 286:
ATmega48A/PA/88A/PA/168A/PA/328/PNo
Page 287 and 288:
Page 289 and 290:
Page 291 and 292:
ATmega48A/PA/88A/PA/168A/PA/328/P;
Page 293 and 294:
Page 295 and 296:
Page 297 and 298:
Page 299 and 300:
Page 301 and 302:
Page 303 and 304:
Page 305 and 306:
Page 307 and 308:
ATmega48A/PA/88A/PA/168A/PA/328/PWh
Page 309 and 310:
Page 311 and 312:
Page 313 and 314:
Page 315 and 316:
Page 317 and 318:
Page 319 and 320:
Page 321 and 322:
Page 323 and 324:
Page 325 and 326:
Page 327 and 328:
Page 329 and 330:
Page 331 and 332:
Page 333 and 334:
Page 335 and 336:
Page 337 and 338:
Page 339 and 340:
Page 341 and 342:
Page 343 and 344:
Page 345 and 346:
Page 347 and 348:
Page 349 and 350:
Page 351 and 352:
Page 353 and 354:
Page 355 and 356:
Page 357 and 358:
Page 359 and 360:
Page 361 and 362:
Page 363 and 364:
Page 365 and 366:
Page 367 and 368:
Page 369 and 370:
Page 371 and 372:
Page 373 and 374:
Page 375 and 376:
Page 377 and 378:
Page 379 and 380:
Page 381 and 382:
Page 383 and 384:
Page 385 and 386:
Page 387 and 388:
Page 389 and 390:
Page 391 and 392:
Page 393 and 394:
Page 395 and 396:
Page 397 and 398:
Page 399 and 400:
Page 401 and 402:
Page 403 and 404:
Page 405 and 406:
Page 407 and 408:
Page 409 and 410:
Page 411 and 412:
Page 413 and 414:
Page 415 and 416:
Page 417 and 418:
Page 419 and 420:
Page 421 and 422:
Page 423 and 424:
Page 425 and 426:
Page 427 and 428:
Page 429 and 430:
Page 431 and 432:
Page 433 and 434:
Page 435 and 436:
Page 437 and 438:
Page 439 and 440:
Page 441 and 442:
Page 443 and 444:
Page 445 and 446:
Page 447 and 448:
Page 449 and 450:
Page 451 and 452:
Page 453 and 454:
Page 455 and 456:
Page 457 and 458:
Page 459 and 460:
Page 461 and 462:
Page 463 and 464:
Page 465 and 466:
Page 467 and 468:
Page 469 and 470:
Page 471 and 472:
Page 473 and 474:
Page 475 and 476:
Page 477 and 478:
Page 479 and 480:
Page 481 and 482:
Page 483 and 484:
Page 485 and 486:
Page 487 and 488:
Page 489 and 490:
Page 491 and 492:
Page 493 and 494:
Page 495 and 496:
Page 497 and 498:
Page 499 and 500:
Page 501 and 502:
Page 503 and 504:
Page 505 and 506:
Page 507 and 508:
Page 509 and 510:
Page 511 and 512:
Page 513 and 514:
Page 515 and 516:
Page 517 and 518:
Page 519 and 520:
Page 521 and 522:
Page 523 and 524:
Page 525 and 526:
Page 527 and 528:
Page 529 and 530:
Page 531 and 532:
Page 533 and 534:
Page 535 and 536:
ATmega48A/PA/88A/PA/168A/PA/328/PAd
Page 537 and 538:
Page 539 and 540:
ATmega48A/PA/88A/PA/168A/PA/328/PMn
Page 541 and 542:
Page 543 and 544:
Page 545 and 546:
Page 547 and 548:
Page 549 and 550:
Page 551 and 552:
Page 553 and 554:
Page 555 and 556:
Page 557 and 558:
Page 559 and 560:
Page 561 and 562:
Page 563 and 564:
Page 565 and 566:
Page 567:
Atmel Corporation2325 Orchard Parkw
show all

ATMega chip full datasheet - UCSD Department of Physics

Create successful ePaper yourself

Delete template?

Save as template?