Library to use 25LCxxx chips
Fork of 25LCxxx_SPI by
Ser25lcxxx.cpp
- Committer:
- hlipka
- Date:
- 2011-01-26
- Revision:
- 0:238ca4fdef8c
- Child:
- 1:c29a67c7034d
File content as of revision 0:238ca4fdef8c:
#include "Ser25lcxxx.h" #include "wait_api.h" #define HIGH(x) ((x&0xff00)>>8) #define LOW(x) (x&0xff) Ser25LCxxx::Ser25LCxxx(SPI *spi, PinName enable, int bytes, int pagesize) { _spi=spi; _enable=new DigitalOut(enable); _size=bytes; _pageSize=pagesize; _enable->write(1); } Ser25LCxxx::~Ser25LCxxx() { delete _enable; } char* Ser25LCxxx::read(unsigned int startAdr, unsigned int len) { // assertion if (startAdr+len>_size) return NULL; char* ret=(char*)malloc(len); _enable->write(0); wait_us(1); // send address if (_size<512) { // 256 and 128 bytes _spi->write(0x03); _spi->write(LOW(startAdr)); } else if (512==_size) { // 4k variant adds 9th address bit to command _spi->write(startAdr>255?0xb:0x3); _spi->write(LOW(startAdr)); } else if (_size<131072) { // everything up to 512k _spi->write(0x03); _spi->write(HIGH(startAdr)); _spi->write(LOW(startAdr)); } else { // 25xx1024, needs 3 byte address _spi->write(0x03); _spi->write(startAdr>>16); _spi->write(HIGH(startAdr)); _spi->write(LOW(startAdr)); } // read data into buffer for (int i=0;i<len;i++) { ret[i]=_spi->write(0); } wait_us(1); _enable->write(1); return ret; } bool Ser25LCxxx::write(unsigned int startAdr, unsigned int len, const char* data) { if (startAdr+len>_size) return -1; int ofs=0; while (ofs<len) { // calculate amount of data to write into current page int pageLen=_pageSize-((startAdr+ofs)%_pageSize); if (ofs+pageLen>len) pageLen=len-ofs; // write single page bool b=writePage(startAdr+ofs,pageLen,data+ofs); if (!b) return false; // and switch to next page ofs+=pageLen; } return true; } bool Ser25LCxxx::writePage(unsigned int startAdr, unsigned int len, const char* data) { enableWrite(); _enable->write(0); wait_us(1); if (_size<512) { // 256 and 128 bytes _spi->write(0x02); _spi->write(LOW(startAdr)); } else if (512==_size) { // 4k variant adds 9th address bit to command _spi->write(startAdr>255?0xa:0x2); _spi->write(LOW(startAdr)); } else if (_size<131072) { // everything up to 512k _spi->write(0x02); _spi->write(HIGH(startAdr)); _spi->write(LOW(startAdr)); } else { // 25xx1024, needs 3 byte address _spi->write(0x02); _spi->write(startAdr>>16); _spi->write(HIGH(startAdr)); _spi->write(LOW(startAdr)); } // do real write for (int i=0;i<len;i++) { _spi->write(data[i]); } wait_us(1); // disable to start physical write _enable->write(1); waitForWrite(); return true; } bool Ser25LCxxx::clearPage(unsigned int pageNum) { enableWrite(); if (_size<65535) { char* s=(char*)malloc(_pageSize); for (int i=0;i<_pageSize;i++) { s[i]=0xff; } bool b=writePage(_pageSize*pageNum,_pageSize,s); delete s; return b; } else { _enable->write(0); wait_us(1); _spi->write(0x42); _spi->write(HIGH(_pageSize*pageNum)); _spi->write(LOW(_pageSize*pageNum)); wait_us(1); _enable->write(1); waitForWrite(); } return true; } void Ser25LCxxx::clearMem() { enableWrite(); if (_size<65535) { for (int i=0;i<_size/_pageSize;i++) { if (!clearPage(i)) break; } } else { _enable->write(0); wait_us(1); _spi->write(0xc7); wait_us(1); _enable->write(1); waitForWrite(); } } int Ser25LCxxx::readStatus() { _enable->write(0); wait_us(1); _spi->write(0x5); int status=_spi->write(0x00); wait_us(1); _enable->write(1); return status; } void Ser25LCxxx::waitForWrite() { while (true) { if (0==readStatus()&1) break; wait_us(10); } } void Ser25LCxxx::enableWrite() { _enable->write(0); wait_us(1); _spi->write(0x06); wait_us(1); _enable->write(1); }