Samuel Mokrani
USBMSD SD card Hello World for Mbed platforms
Dependencies: mbed USBMSD_SD USBDevice
Diff: USBDevice/USBMSD/AT45.cpp
- Revision:
- 3:0ffb2eee9e06
- Parent:
- 2:27a7e7f8d399
- Child:
- 4:980e6470dcce
--- a/USBDevice/USBMSD/AT45.cpp Fri Nov 11 15:22:53 2011 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,829 +0,0 @@
-#include "AT45.h"
-#include "mbed.h"
-
-/* mbed Library - AT45
- * (c)2007, cstyles
- */
-
-
-
-/*
- * Constructor
- */
-
-AT45::AT45(PinName mosi, PinName miso, PinName clk, PinName ncs)
- : _spi(mosi, miso, clk), _ncs(ncs) {
-
- _pages = -1; // number of pages
- _pagesize = -1; // size of pages 256/264, 512/528, 1024/1056
- _devicesize = -1; // In bytes
-
- _buffer1address = -1; // page address in buffer 1
- _buffer2address = -1; // page address in buffer 2
- _lru = -1; // leas recently used buffer (for eviction)
-
- _reset(); // Populate all this stuff
-
-}
-
-
-
-
-
-/*
- * This is the reset function of the constructor.
- * Interrogate the part and set up some variables.
- */
-
-void AT45::_reset() {
- int _id = 0;
- int _status = 0;
-
- _spi.format(8,0);
- _spi.frequency(5000000);
-
- _id = id();
- _status = status();
-
- if ( (_id & 0x1f) == 0x2) { // 1Mbit
- _devicesize = 131072; // size in bytes
- _pages = 512; // number of pages
- _blocks = 256; // Number of 512 byte blocks
- if (_status & 0x1) {
- _pagesize = 256;}
- else {
- _pagesize = 264;}
- }
-
- else if ( (_id & 0x1f) == 0x3) { // 2M
- _devicesize = 262144; // Size in bytes
- _pages = 1024; // Number of pages
- _blocks = 512; // Number of 512 byte blocks
- if (_status & 0x1) {
- _pagesize = 256;}
- else {
- _pagesize = 264;}
- }
-
- else if ( (_id & 0x1f) == 0x4) { // 4M
- _devicesize = 524288;
- _pages = 2048;
- _blocks = 1024; // Number of 512 byte blocks
- if (_status & 0x1) {
- _pagesize = 256;}
- else {
- _pagesize = 264;}
- }
-
- else if ( (_id & 0x1f) == 0x5) { // 8M
- _devicesize = 1048576;
- _pages = 4096;
- _blocks = 2048; // Number of 512 byte blocks
- if (_status & 0x1) {
- _pagesize = 256;}
- else {
- _pagesize = 264;}
- }
-
- else if ( (_id & 0x1f) == 0x6) { // 16M
- _devicesize = 2097152;
- _pages = 4096;
- _blocks = 4096; // Number of 512 byte blocks
- if (_status & 0x1) {
- _pagesize = 512;}
- else {
- _pagesize = 528;}
- }
-
- else if ( (_id & 0x1f) == 0x7) { // 32M
- _devicesize = 4194304;
- _pages = 8192;
- _blocks = 8192; // Number of 512 byte blocks
- if (_status & 0x1) {
- _pagesize = 512;}
- else {
- _pagesize = 528;}
- }
-
- else if ( (_id & 0x1f) == 0x8) { // 64M
- _devicesize = 8388608;
- _pages = 8192;
- _blocks = 16384;
- if (_status & 0x1) {
- _pagesize = 1024;}
- else {
- _pagesize = 1056;}
- }
-
- else {
- _devicesize = -1;
- _pages = -1;
- _pagesize = -1;
- }
-}
-
-
-
-
-
-/*
- * Select pulls nCS low, but also ensure SPI channel is formatted
- * This is so that another device sharing the same SPI pins
- * doenst leave it in an unknown state
- */
-
-void AT45::_select() {
- // ensure that the SPI port is set up correctly still
- // This allows SPI channel sharing
- _spi.format(8,0);
- _spi.frequency(5000000);
- _ncs = 0;
-}
-
-
-
-
-
-/*
- * Deselect simply returns nCS to high
- */
-void AT45::_deselect() {
- _ncs = 1;
-}
-
-
-
-
-
-/*
- * Work out the page address
- * If we have a 2^N page size, it is just the top N bits
- * If we have non-2^N, we use the shifted address
- */
-
-int AT45::_getpaddr(int address) {
-
- int paddr;
-
- if (_pagesize == 256) {
- paddr = address & 0xffffff00;}
- else if (_pagesize == 264) {
- paddr = (address << 1) & 0xfffffe00;}
- else if (_pagesize == 512) {
- paddr = address & 0xfffffe00;}
- else if (_pagesize == 528 ) {
- paddr = (address << 1) & 0xfffffc00;}
- else if (_pagesize == 1024) {
- paddr = address & 0xfffffc00;}
- else if (_pagesize == 1056 ) {
- paddr = (address << 1) & 0xfffff800;}
- else {
- paddr = 0xdeadbeef;}
-
- return (paddr);
-
-}
-
-
-
-
-
-/*
- * Clean the buffer address. This is the 8/9/10 LSBs
- */
-
-int AT45::_getbaddr(int address) {
-
- int baddr;
-
- if ((_pagesize == 256) || (_pagesize == 264 )) {
- baddr = address & 0xff;}
- else if ((_pagesize == 512) || (_pagesize == 528 )) {
- baddr = address & 0x1ff;}
- else if ((_pagesize == 1024) || (_pagesize == 1056 )) {
- baddr = address & 0x3ff;}
- else {
- baddr = 0xcafebabe;}
-
- return (baddr);
-}
-
-
-
-
-
-/*
- * Return the Id of the part
- */
-
-int AT45::id() {
- int id = 0;
- _select();
- _spi.write(0x9f);
- id = (_spi.write(0x00) << 8);
- id |= _spi.write(0x00);
- _deselect();
- return id;
-}
-
-
-
-
-
-/*
- * return the Status
- */
-
-int AT45::status() {
- int status = 0;
- _select();
- _spi.write(0xd7);
- status = (_spi.write(0x00) << 8 );
- status |= _spi.write(0x00);
- _deselect();
- return status;
-}
-
-
-
-
-
-/*
- * Erase the entire chip
- */
-
-void AT45::erase() {
-
- _pollbusy(); // make sure flash isnt already in busy.
-
- // There are errata on this. For now, do itthe long way :-(
- _select();
- // 4 byte command sequence
- _spi.write(0xc7);
- _spi.write(0x94);
- _spi.write(0x80);
- _spi.write(0x9a);
- _deselect();
-
- _pollbusy(); // Make erase a blocking function
-
-}
-
-
-
-
-
-/*
- * return the size of the part in bytes
- */
-
-int AT45::size() {
- return _devicesize;
-}
-
-
-
-
-
-/*
- * return the page size of the part in bytes
- */
-
-int AT45::pagesize() {
- return _pagesize;
-}
-
-
-
-
-
-/*
- * return the numbers of pages
- */
-
-int AT45::pages() {
- return _pages;
-}
-
-
-
-
-
-/*
- * Make sure the Flash isnt already doing something
- */
-void AT45::_pollbusy() {
- volatile int busy = 1;
- while (busy) {
- // if bit 7 is set, we can proceed
- if ( status() & 0x80 ) {
- busy = 0;}
- }
-}
-
-
-
-
-
-/*
- * Make sure the Flash isnt already doing something
- */
-
-void AT45::pollbusy() {
- _pollbusy();
-}
-
-
-
-
-
-/*
- * This function returns the char
- */
-
-char AT45::read(int address) {
- // return byte from address
- return (_memread( address ));
-}
-
-
-
-
-
-/*
- * This function writes the char to the address supplied
- * Note : We pass the raw address to the underlying functions
- */
-
-void AT45::write(int address, char data) {
-
- _pollbusy();
- _flashread(1,address); // read the Flash page into SRAM buffer
- _pollbusy(); // wait for the read to complete
- _sramwrite(1,address,data); // Write new data into SRAM
- _pollbusy(); // Make sure flash isnt busy
- _flashwrite(1,address); // Write back to the page address
-}
-
-
-
-
-
-/*
- * Read from an SRAM buffer
- * Note : We create buffer and page addresses in _sram and _flash
- */
-
-int AT45::_sramread(int buffer, int address) {
-
- int cmd = 0;
- int baddr = 0;
-
- baddr = _getbaddr(address);
-
- _select();
-
- if(buffer == 1)
- {cmd = 0xd4;}
- else
- {cmd = 0xd6;}
-
- _spi.write(cmd);
- _sendaddr (baddr);
- _spi.write (0x0); // dont care byte
- cmd = _spi.write (0x0);
-
- _deselect();
-
- return (cmd);
-}
-
-
-
-
-
-
-/*
- * Write to an SRAM buffer
- * Note : We create buffer and page addresses in _sram and _flash
- */
-
-void AT45::_sramwrite(int buffer, int address, int data) {
-
- int cmd = 0;
- int baddr = 0;
-
- baddr = _getbaddr(address);
-
- _pollbusy();
-
- _select();
-
- if (buffer == 1)
- {cmd = 0x84;}
- else
- {cmd = 0x87;}
-
- _spi.write(cmd);
- _sendaddr (baddr);
- _spi.write (data);
-
- _deselect();
-}
-
-
-
-
-
-/*
- * Read from Flash memory into SRAM buffer
- */
-
-void AT45::_flashread (int buffer, int address) {
-
- int cmd = 0;
- int paddr = _getpaddr(address); // calculate page address
-
- _pollbusy(); // Check flash is not busy
- _select();
-
- if (buffer == 1)
- {cmd = 0x53;}
- else
- {cmd = 0x55;}
-
- _spi.write (cmd);
- _sendaddr (paddr);
- _deselect();
-
-}
-
-
-
-
-
-/*
- * Write and SRAM buffer back to main memory
- */
-
-void AT45::_flashwrite (int buffer, int address) {
-
- int cmd = 0;
- int paddr = _getpaddr(address);
-
- _pollbusy(); // Check flash is not busy
-
- _select();
-
- if (buffer == 1)
- {cmd = 0x83;}
- else
- {cmd = 0x86;}
-
- _spi.write (cmd);
- _sendaddr (paddr);
- _deselect();
-
- _pollbusy(); // Check flash is not busy
-
-}
-
-
-
-
-
-/*
- * Read directly from main memory
- */
-
-int AT45::_memread (int address) {
-
- int data = 0;
- int addr;
-
- addr = _getpaddr(address) | _getbaddr(address);
-
- _pollbusy();
-
- _select();
-
- _spi.write (0xd2); // Direct read command
- _sendaddr (addr);
-
- // 4 dont care bytes
- _spi.write (0x00);
- _spi.write (0x00);
- _spi.write (0x00);
- _spi.write (0x00);
-
- // this one clocks the data
- data = _spi.write (0x00);
- _deselect();
-
- _pollbusy();
-
- return data;
-}
-
-
-
-
-
-/*
- * Sends the three lest significant bytes of the supplied address
- */
-
-void AT45::_sendaddr (int address) {
- _spi.write(address >> 16);
- _spi.write(address >> 8);
- _spi.write(address);
-}
-
-
-
-
-
-/*
- * Return the number of 512 byte blocks in this device
- */
-
-int AT45::blocks(void) {
- return _blocks;
-}
-
-
-
-
-
-/*
- * Read the numbered block into the data array supplied
- */
-
-int AT45::blockread (char* data, int block) {
-
- // For 256 byte pages, we read two pages
- if((_pagesize == 256) || (_pagesize == 264)) {
-
- int address = block * 512; // This is the start address of the 512 byte block
-
- _flashread(1,address); // read the first page of the block into SRAM buffer 1
- _pollbusy(); // Wait until First page has loaded into buffer 1
-
- // I'll do this directly as we are reading back an entire buffer, and this can be done more optimally
- // than using _sramread
- _select();
- _spi.write(0xd4);
- _sendaddr (0x0);
- _spi.write (0x0); // dont care byte
-
- for(int i=0;i<256;i++) {
- data[i] = _spi.write (0x0);
- }
- _deselect();
-
- _flashread(1,address+256); // read the second page of the block into SRAM buffer 2
- _pollbusy(); // Wait until second page has loaded into buffer 2
-
- // Now the second page is loaded, pull this out into the second half of the data buffer
- // I'll do this directly as we are reading back an entire buffer, and this can be done more optimally
- // than using _sramread
- _select();
- _spi.write(0xd4);
- _sendaddr (0x0);
- _spi.write (0x0); // dont care byte
-
- for(int i=0;i<256;i++) {
- data[256+i] = _spi.write (0x0);
- }
- _deselect();
- return (0);
- }
-
-
- // For 512 byte pages, we read just the single page, transfer it
- else if((_pagesize == 512) || (_pagesize == 528)) {
-
- int address = block * 512; // This is the start address of the 512 byte block
-
- _pollbusy(); // Wait until First page has loaded into buffer 1
- _flashread(1,address); // read the first page of the block into SRAM buffer 1
- _pollbusy(); // Wait until First page has loaded into buffer 1
-
- // Now the page has loaded, simply transfer it from the sram buffer to the data array
- // I'll do this directly as we are reading back an entire buffer, and this can be done more optimally
- // than using _sramread
- _select();
- _spi.write(0xd4);
- _sendaddr (0x0);
- _spi.write (0x0); // dont care byte
-
- for(int i=0;i<512;i++) {
- data[i] = _spi.write (0x0);
- }
- _deselect();
- return (0);
- }
-
-
- // For 1024 byte pages, we read just a single page, transfer half of it
- else if((_pagesize == 1024) || (_pagesize == 1056)) {
- int address = _getpaddr(block * 512); // This is the start address of the 512 byte block
-
- _pollbusy(); // Wait until First page has loaded into buffer 1
-
- _flashread(1,address); // read the first page of the block into SRAM buffer 1
-
- _pollbusy(); // Wait until First page has loaded into buffer 1
-
- // Now the page has loaded, simply transfer it from the sram buffer to the data array
- // I'll do this directly as we are reading back an entire buffer, and this can be done more optimally
- // than using _sramread
-
- _select();
- _spi.write(0xd4);
-
- if (block %2) { // odd numbered block, read from adress 0x200
- _sendaddr (0x200);
- }
- else {// even numbered block, then we are reading from sram buffer 0x0
- _sendaddr (0x0);
- }
-
-
- _spi.write (0x0); // dont care byte
-
- for(int i=0;i<512;i++) {
- data[i] = _spi.write (0x0);
- }
- _deselect();
- return (0);
- }
-
- else {
- return (-1); // something isnt configured right
- }
-}
-
-
-
-
-
-/*
- * Write the buffer to the numbered block
- */
-
-int AT45::blockwrite(char* data, int block) {
-
- // For 256 byte pages, we overwrite two pages
- if((_pagesize == 256) || (_pagesize == 264)) {
-
- // fill the first buffer with the first half of the block
- // do this directly, for better performance
- _select();
- _spi.write(0x84); // writing to buffer #1
- _sendaddr (0); // we are writing to the entire buffer
-
- for(int i=0;i<256;i++) {
- _spi.write (data[i]);
- }
- _deselect();
-
- _flashwrite(1,(block*512));
-
- // fill the buffer with the second half of the block
- // do this directly, for better performance
- _select();
- _spi.write(0x84); // writing to buffer #1
- _sendaddr (0); // we are writing to the entire buffer
-
- for(int i=0;i<256;i++) {
- _spi.write (data[256+i]);
- }
- _deselect();
-
- _flashwrite(1,((block*512)+256));
- }
-
-
- // For 512 byte pages, we overwrite a single page
- else if((_pagesize == 512) || (_pagesize == 528)) {
-
- // fill the first buffer with the block data
- // do this directly, for better performance
- _select();
- _spi.write(0x84); // writing to buffer #1
- _sendaddr (0); // we are writing to the entire buffer
-
- for(int i=0;i<512;i++) {
- _spi.write (data[i]);
- }
- _deselect();
-
- _pollbusy(); // make sure the Flahs isnt busy
-
- // issue command to write buffer 1 to the appropraite flash page
- _select();
- _spi.write (0x83);
- _sendaddr (_getpaddr(block * 512));
- _deselect();
- _pollbusy(); // make sure the Flahs isnt busy
- }
-
-
- // For 1024 byte pages, we do a read modify write
- // must make sure we overwrite the right half of the page!
- else if((_pagesize == 1024) || (_pagesize == 1056)) {
-
- _pollbusy(); // make sure the flash isnt busy
-
- int address = _getpaddr(block*512);
-
- // Read the page into sram
- _flashread(1,address);
-
- // wait for this operation to complete
- _pollbusy();
-
- // Overwrite the appropriate half
- // do this directly, for better performance
- _select();
- _spi.write(0x84); // writing to buffer #1
-
- if(block%2) { // this is an odd block number, overwrite second half of buffer
- _sendaddr (0x200); // we are writing to the entire buffer
- }
- else { // this is an even block, overwrite the first half
- _sendaddr (0x0); // we are writing to the entire buffer
- }
-
- for(int i=0;i<512;i++) {
- _spi.write (data[i]);
- }
- _deselect();
-
- // Write the page back
- _pollbusy();
- _flashwrite(1,address);
-
- }
-
-
- // Something has gone wrong
- else {
- return (-1);
- }
-
- return (0);
-}
-
-
-/*
- * Return the number of 512 byte blocks in this device
- */
-void blockerase (int block) {}
-
-
-
-/*
- * returns the number of buffer to use
- * If page is already open, use it
- * If one of the buffers is unused, use it
- * else evict the least recently used.
-
- */
-int _allocatebuffer (int address) {
-
- int buf = 0;
- // is page already open in buffer 1?
- // is page already open in buffer 2
- // is buffer 1 unusued?
- // is buffer 2 unused
- // evict LRU
-
- return (buf);
-
-}
-
-
-
-/*
- * write the buffer back to flash
- * set it as LRU
- * make _bufferNaddress = -1
- */
-void _flushbuffer (int buffer) {
-
- // is page already open in buffer 1?
- // is page already open in buffer 2
- // is buffer 1 unusued?
- // is buffer 2 unused
- // evict LRU
-
-}
-
-
-
-
-
-
-
\ No newline at end of file