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The "enable write status" command has to be sent before "write status" command to unlock memory area.
Fork of SST25VF by
SST25VF.cpp
- Committer:
- emmibed
- Date:
- 2012-01-15
- Revision:
- 0:1633dfa4b768
- Child:
- 1:533050c756e0
File content as of revision 0:1633dfa4b768:
/* SST25VF - drive the Microchip SST25VF Serial Flash using SPI */ #include "mbed.h" #include "SST25VF.h" SST25VF::SST25VF(SPI& spi, PinName ncs) : _spi(spi), _ncs(ncs) { _spi.format(8,0); _spi.frequency(SPI_FREQ); deselect(); unlock(); chipErase(); } void SST25VF::select() { _ncs = 0; } void SST25VF::deselect() { _ncs = 1; } void SST25VF::wren() { select(); _spi.write(WREN); deselect(); waitShort(); } void SST25VF::wrdi() { select(); _spi.write(WRDI); deselect(); } void SST25VF::chipErase() { wren(); select(); _spi.write(CHIP_ERASE); deselect(); waitErase(); } void SST25VF::unlock() { select(); _spi.write(WRITE_STATUS); _spi.write(0); deselect(); waitShort(); } void SST25VF::writeStatus(char status) { select(); _spi.write(WRITE_STATUS); _spi.write(status); deselect(); waitShort(); } char SST25VF::readStatus() { select(); _spi.write(READ_STATUS); char result = (char) _spi.write(0); deselect(); return result; } void SST25VF::prepareCommand(char command, long int address) { select(); _spi.write(command); _spi.write((address & 0xFFFFFF) >> 16); _spi.write((address & 0xFFFF)>> 8); _spi.write(address & 0xFF); } // write or read a single byte void SST25VF::write(long int address, char byte) { wren(); prepareCommand(WRITE, address); _spi.write(byte); deselect(); waitShort(); } char SST25VF::read(long int address) { prepareCommand(READ, address); int result = _spi.write(0); deselect(); return (char) result; } // continuous write and read void SST25VF::write(long int address, char * buffer, int count) { wren(); // write frist two bytes for (int i = 0; i < count-1; i=i+2) { if (i==0) { prepareCommand(AAIWRITE, address); } else { select(); _spi.write(AAIWRITE); } _spi.write(buffer[i]); _spi.write(buffer[i+1]); deselect(); waitShort(); } if ((count % 2) == 1) { // odd number of bytes select(); _spi.write(AAIWRITE); _spi.write(buffer[count-1]); _spi.write(0); // odd number of bytes, so write dummy byte to flash deselect(); waitShort(); } wrdi(); waitShort(); } void SST25VF::read(long int address, char * buffer, int count) { prepareCommand(READ, address); // _spi.write(0); // dummy cycle, only necessary if READ is replaced by HSREAD for (int i = 0; i < count; i++) { buffer[i] = _spi.write(0); } deselect(); }