VLSI Solution Oy Evaluation MP3 Player Source Code Documentation

00239 { 00240 unsigned char c; 00241 00242 //Switch off the MMC power supply 00243 MMC_OFF = YES; 00244 ConsoleWrite ("Init: MMC\r"); 00245 Delay(100); 00246 00247 //Switch on the MMC power supply 00248 MMC_OFF = NO; 00249 Delay(100); 00250 00251 /* Allow MMC some time and clock cycles to reset */ 00252 for (c=0; c<200; c++){ 00253 SPIPutCharWithoutWaiting(0xff); 00254 SPIWait(); 00255 } 00256 Delay(20); 00257 00258 if (RebootMMC()) return 1; //not able to powerup; 00259 //An existing MMC card should be able to respond now. 00260 00261 GetStorageInformation(); 00262 00263 /* Set Block Size of 512 bytes (2 == 512 << 8) */ 00264 if ((c=MmcCommand(0x50,0,0,2,0))) return c|0x80; /* blocksize error */ 00265 00266 /* Check if MMC supports interrupted data transfer */ 00267 /* This does a simple checksum check to see if interrupted and 00268 * non-interrupted read blocks are the same. */ 00269 /* This could be a function, so it is in braces for clarity purposes */ 00270 { 00271 if (SeekSector(0)) return 2; //Storage powerup failure 00272 if (ReadPhysicalSector()) return 2; //Storage powerup failure 00273 00274 temp.i = diskSect.raw.buf[511]; 00275 for (c=0; c<250; c++){ 00276 temp.i += diskSect.raw.buf[c]; 00277 } 00278 00279 if (SeekSector(0)) return 2;//Storage powerup failure 00280 00281 /* Send some extra SPI clocks */ 00282 MMC_XCS = MMC_NOT_SELECTED; 00283 SPIPutCharWithoutWaiting(0xff); 00284 for (c=0; c<100; c++){ 00285 SPIPutChar(0xff); 00286 } 00287 SPIWait(); 00288 00289 if (ReadPhysicalSector()){ 00290 ConsoleWrite("Interrupted read failed.\r"); 00291 ConsoleWrite("Using compatibility mode.\r"); 00292 return 0x0e; //ok but no support for seek-before-read 00293 00294 }else{ 00295 //Check if received data was same 00296 temp.i -= diskSect.raw.buf[511]; 00297 for (c=0; c<250; c++){ 00298 temp.i -= diskSect.raw.buf[c]; 00299 } 00300 } 00301 00302 if (temp.i) { /* Checksum does not match */ 00303 ConsoleWrite("This MMC has no support for interrupted read. "); 00304 ConsoleWrite("Using compatibility mode.\r"); 00305 return 0x0e; //ok but no support for seek-before-read 00306 } 00307 00308 ConsoleWrite("\rInitMMC ok.\r"); 00309 } 00310 00311 /* All OK return */ 00312 return 0; //ok and MMC supports seek-before-read 00313 00314 }

00464 { 00465 00466 RED_LED = LED_ON; /* Disk Read LED on */ 00467 00468 MMC_XCS = MMC_SELECTED; 00469 MmcWaitForData(); 00470 PerformBlockRead(); 00471 00472 /* generate SPI clock edges to finish up the command */ 00473 00474 SPI8Clocks(4); //Send 8*4=32 clocks (4 ff's) to MMC to be nice. 00475 MMC_XCS = MMC_NOT_SELECTED; 00476 SPI8Clocks(4); //Again, give the poor MMC some clocks, it likes them. 00477 00478 RED_LED = LED_OFF; /* Disk Read LED off */ 00479 00480 return 0; //ok return 00481 }

00418 { 00419 00420 unsigned char c; 00421 00422 #ifdef MMCDEBUG 00423 ConsoleWrite("{s"); //Seek called 00424 #endif 00425 00426 do{ 00427 sectorAddress.l = sectorN * 2; //convert to bytes (combined with 8bit shift) 00428 c=MmcCommand(0x51,sectorAddress.b.b2,sectorAddress.b.b1, 00429 sectorAddress.b.b0, 0); 00430 sectorAddress.l = sectorAddress.l >> 1; //convert back to blocks 00431 00432 //if MMC returs "nothing" (0xff) or 0x81(busy), 00433 //toggle chip select and retry 00434 if ((c==0xff)||(c==0x81)){ 00435 c=0xff; 00436 RebootMMC(); 00437 } 00438 if (c==0x01){ //MMC says "busy" 00439 c=0xff; //try again 00440 } 00441 00442 }while(c==0xff); //repeat until we get signal from MMC. 00443 00444 if ((c & 0xfe)){ //MMC returns something else than idle or busy signal 00445 ConsoleDecipherMMCResponse(c); 00446 MMC_XCS = MMC_NOT_SELECTED; 00447 00448 #ifdef MMCDEBUG 00449 ConsoleWrite("!s}"); 00450 #endif 00451 return 7; /* failed to execute mmc command */ 00452 } 00453 00454 MMC_XCS = MMC_NOT_SELECTED; 00455 00456 #ifdef MMCDEBUG 00457 ConsoleWrite("s}"); 00458 #endif 00459 return 0; //ok return 00460 }

00485 { 00486 unsigned char c; 00487 00488 #ifdef MMCDEBUG 00489 ConsoleWrite("<W"); 00490 #endif 00491 00492 RED_LED = LED_ON; 00493 sectorAddress.l = sectorAddress.l * 2; //convert to bytes (combined with 8bit shift) 00494 c=MmcCommand(24 | 0x40 ,sectorAddress.b.b2,sectorAddress.b.b1, 00495 sectorAddress.b.b0, 0); 00496 sectorAddress.l = sectorAddress.l >> 1; //convert back to blocks 00497 MMC_XCS = MMC_SELECTED; 00498 00499 00500 dataBufPtr = diskSect.raw.buf; 00501 SPIPutCharWithoutWaiting(0xFE); 00502 SPIWait(); 00503 00504 for (c=0;c<128;c++){ 00505 SPIPutCharWithoutWaiting(*dataBufPtr++); 00506 SPIWait(); 00507 SPIPutCharWithoutWaiting(*dataBufPtr++); 00508 SPIWait(); 00509 SPIPutCharWithoutWaiting(*dataBufPtr++); 00510 SPIWait(); 00511 SPIPutCharWithoutWaiting(*dataBufPtr++); 00512 SPIWait(); 00513 } 00514 00515 MmcWaitForData(); //Wait for 0xFE token 00516 while (SPIGetChar()==0) 00517 ; // Wait until MMC not busy. 00518 00519 #ifdef MMCDEBUG 00520 ConsoleWrite("W>"); 00521 #endif 00522 00523 00524 SPI8Clocks(16); 00525 MMC_XCS = MMC_NOT_SELECTED; 00526 SPI8Clocks(16); 00527 00528 RED_LED = LED_OFF; 00529 00530 }


Functions
unsigned char	InitMMC ()
	Start-up the MMC card.
unsigned char	SeekSector (unsigned long sectorN)
	Perform MMC Seek Command for offset sectorN*512.
unsigned char	ReadPhysicalSector ()
	Perform block read of previously sought sector to diskSect.
unsigned char	WritePhysicalSector ()
	Perform MMC block write from *dataBufPtr to sector sectorAddress.l.
Variables
xdata unsigned char	storageFlags
	Storage status flags.

mmc.h File Reference

Functions

Variables

Detailed Description

Function Documentation

Variable Documentation