Pierre Emmibed
Library for the SST25VF016B serial flash from Microchip (16Mbit Serial Flash).
SST25VF.cpp@0:1633dfa4b768, 2012-01-15 (annotated)
- Committer:
- emmibed
- Date:
- Sun Jan 15 13:51:16 2012 +0000
- Revision:
- 0:1633dfa4b768
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| emmibed | 0:1633dfa4b768 | 1 | /* SST25VF - drive the Microchip SST25VF Serial Flash using SPI |
| emmibed | 0:1633dfa4b768 | 2 | */ |
| emmibed | 0:1633dfa4b768 | 3 | |
| emmibed | 0:1633dfa4b768 | 4 | #include "mbed.h" |
| emmibed | 0:1633dfa4b768 | 5 | #include "SST25VF.h" |
| emmibed | 0:1633dfa4b768 | 6 | |
| emmibed | 0:1633dfa4b768 | 7 | SST25VF::SST25VF(SPI& spi, PinName ncs) : _spi(spi), _ncs(ncs) { |
| emmibed | 0:1633dfa4b768 | 8 | |
| emmibed | 0:1633dfa4b768 | 9 | _spi.format(8,0); |
| emmibed | 0:1633dfa4b768 | 10 | _spi.frequency(SPI_FREQ); |
| emmibed | 0:1633dfa4b768 | 11 | deselect(); |
| emmibed | 0:1633dfa4b768 | 12 | unlock(); |
| emmibed | 0:1633dfa4b768 | 13 | chipErase(); |
| emmibed | 0:1633dfa4b768 | 14 | |
| emmibed | 0:1633dfa4b768 | 15 | } |
| emmibed | 0:1633dfa4b768 | 16 | |
| emmibed | 0:1633dfa4b768 | 17 | void SST25VF::select() { |
| emmibed | 0:1633dfa4b768 | 18 | _ncs = 0; |
| emmibed | 0:1633dfa4b768 | 19 | } |
| emmibed | 0:1633dfa4b768 | 20 | |
| emmibed | 0:1633dfa4b768 | 21 | void SST25VF::deselect() { |
| emmibed | 0:1633dfa4b768 | 22 | _ncs = 1; |
| emmibed | 0:1633dfa4b768 | 23 | } |
| emmibed | 0:1633dfa4b768 | 24 | |
| emmibed | 0:1633dfa4b768 | 25 | void SST25VF::wren() { |
| emmibed | 0:1633dfa4b768 | 26 | select(); |
| emmibed | 0:1633dfa4b768 | 27 | _spi.write(WREN); |
| emmibed | 0:1633dfa4b768 | 28 | deselect(); |
| emmibed | 0:1633dfa4b768 | 29 | waitShort(); |
| emmibed | 0:1633dfa4b768 | 30 | } |
| emmibed | 0:1633dfa4b768 | 31 | |
| emmibed | 0:1633dfa4b768 | 32 | void SST25VF::wrdi() { |
| emmibed | 0:1633dfa4b768 | 33 | select(); |
| emmibed | 0:1633dfa4b768 | 34 | _spi.write(WRDI); |
| emmibed | 0:1633dfa4b768 | 35 | deselect(); |
| emmibed | 0:1633dfa4b768 | 36 | } |
| emmibed | 0:1633dfa4b768 | 37 | |
| emmibed | 0:1633dfa4b768 | 38 | void SST25VF::chipErase() { |
| emmibed | 0:1633dfa4b768 | 39 | wren(); |
| emmibed | 0:1633dfa4b768 | 40 | select(); |
| emmibed | 0:1633dfa4b768 | 41 | _spi.write(CHIP_ERASE); |
| emmibed | 0:1633dfa4b768 | 42 | deselect(); |
| emmibed | 0:1633dfa4b768 | 43 | waitErase(); |
| emmibed | 0:1633dfa4b768 | 44 | } |
| emmibed | 0:1633dfa4b768 | 45 | |
| emmibed | 0:1633dfa4b768 | 46 | void SST25VF::unlock() { |
| emmibed | 0:1633dfa4b768 | 47 | select(); |
| emmibed | 0:1633dfa4b768 | 48 | _spi.write(WRITE_STATUS); |
| emmibed | 0:1633dfa4b768 | 49 | _spi.write(0); |
| emmibed | 0:1633dfa4b768 | 50 | deselect(); |
| emmibed | 0:1633dfa4b768 | 51 | waitShort(); |
| emmibed | 0:1633dfa4b768 | 52 | } |
| emmibed | 0:1633dfa4b768 | 53 | |
| emmibed | 0:1633dfa4b768 | 54 | void SST25VF::writeStatus(char status) { |
| emmibed | 0:1633dfa4b768 | 55 | select(); |
| emmibed | 0:1633dfa4b768 | 56 | _spi.write(WRITE_STATUS); |
| emmibed | 0:1633dfa4b768 | 57 | _spi.write(status); |
| emmibed | 0:1633dfa4b768 | 58 | deselect(); |
| emmibed | 0:1633dfa4b768 | 59 | waitShort(); |
| emmibed | 0:1633dfa4b768 | 60 | } |
| emmibed | 0:1633dfa4b768 | 61 | |
| emmibed | 0:1633dfa4b768 | 62 | char SST25VF::readStatus() { |
| emmibed | 0:1633dfa4b768 | 63 | select(); |
| emmibed | 0:1633dfa4b768 | 64 | _spi.write(READ_STATUS); |
| emmibed | 0:1633dfa4b768 | 65 | char result = (char) _spi.write(0); |
| emmibed | 0:1633dfa4b768 | 66 | deselect(); |
| emmibed | 0:1633dfa4b768 | 67 | return result; |
| emmibed | 0:1633dfa4b768 | 68 | } |
| emmibed | 0:1633dfa4b768 | 69 | |
| emmibed | 0:1633dfa4b768 | 70 | void SST25VF::prepareCommand(char command, long int address) { |
| emmibed | 0:1633dfa4b768 | 71 | select(); |
| emmibed | 0:1633dfa4b768 | 72 | _spi.write(command); |
| emmibed | 0:1633dfa4b768 | 73 | _spi.write((address & 0xFFFFFF) >> 16); |
| emmibed | 0:1633dfa4b768 | 74 | _spi.write((address & 0xFFFF)>> 8); |
| emmibed | 0:1633dfa4b768 | 75 | _spi.write(address & 0xFF); |
| emmibed | 0:1633dfa4b768 | 76 | } |
| emmibed | 0:1633dfa4b768 | 77 | |
| emmibed | 0:1633dfa4b768 | 78 | // write or read a single byte |
| emmibed | 0:1633dfa4b768 | 79 | |
| emmibed | 0:1633dfa4b768 | 80 | void SST25VF::write(long int address, char byte) { |
| emmibed | 0:1633dfa4b768 | 81 | wren(); |
| emmibed | 0:1633dfa4b768 | 82 | prepareCommand(WRITE, address); |
| emmibed | 0:1633dfa4b768 | 83 | _spi.write(byte); |
| emmibed | 0:1633dfa4b768 | 84 | deselect(); |
| emmibed | 0:1633dfa4b768 | 85 | waitShort(); |
| emmibed | 0:1633dfa4b768 | 86 | } |
| emmibed | 0:1633dfa4b768 | 87 | |
| emmibed | 0:1633dfa4b768 | 88 | char SST25VF::read(long int address) { |
| emmibed | 0:1633dfa4b768 | 89 | prepareCommand(READ, address); |
| emmibed | 0:1633dfa4b768 | 90 | int result = _spi.write(0); |
| emmibed | 0:1633dfa4b768 | 91 | deselect(); |
| emmibed | 0:1633dfa4b768 | 92 | return (char) result; |
| emmibed | 0:1633dfa4b768 | 93 | } |
| emmibed | 0:1633dfa4b768 | 94 | |
| emmibed | 0:1633dfa4b768 | 95 | // continuous write and read |
| emmibed | 0:1633dfa4b768 | 96 | |
| emmibed | 0:1633dfa4b768 | 97 | void SST25VF::write(long int address, char * buffer, int count) { |
| emmibed | 0:1633dfa4b768 | 98 | wren(); |
| emmibed | 0:1633dfa4b768 | 99 | // write frist two bytes |
| emmibed | 0:1633dfa4b768 | 100 | for (int i = 0; i < count-1; i=i+2) { |
| emmibed | 0:1633dfa4b768 | 101 | if (i==0) { |
| emmibed | 0:1633dfa4b768 | 102 | prepareCommand(AAIWRITE, address); |
| emmibed | 0:1633dfa4b768 | 103 | } else { |
| emmibed | 0:1633dfa4b768 | 104 | select(); |
| emmibed | 0:1633dfa4b768 | 105 | _spi.write(AAIWRITE); |
| emmibed | 0:1633dfa4b768 | 106 | } |
| emmibed | 0:1633dfa4b768 | 107 | _spi.write(buffer[i]); |
| emmibed | 0:1633dfa4b768 | 108 | _spi.write(buffer[i+1]); |
| emmibed | 0:1633dfa4b768 | 109 | deselect(); |
| emmibed | 0:1633dfa4b768 | 110 | waitShort(); |
| emmibed | 0:1633dfa4b768 | 111 | } |
| emmibed | 0:1633dfa4b768 | 112 | if ((count % 2) == 1) { // odd number of bytes |
| emmibed | 0:1633dfa4b768 | 113 | select(); |
| emmibed | 0:1633dfa4b768 | 114 | _spi.write(AAIWRITE); |
| emmibed | 0:1633dfa4b768 | 115 | _spi.write(buffer[count-1]); |
| emmibed | 0:1633dfa4b768 | 116 | _spi.write(0); // odd number of bytes, so write dummy byte to flash |
| emmibed | 0:1633dfa4b768 | 117 | deselect(); |
| emmibed | 0:1633dfa4b768 | 118 | waitShort(); |
| emmibed | 0:1633dfa4b768 | 119 | } |
| emmibed | 0:1633dfa4b768 | 120 | wrdi(); |
| emmibed | 0:1633dfa4b768 | 121 | waitShort(); |
| emmibed | 0:1633dfa4b768 | 122 | } |
| emmibed | 0:1633dfa4b768 | 123 | |
| emmibed | 0:1633dfa4b768 | 124 | void SST25VF::read(long int address, char * buffer, int count) { |
| emmibed | 0:1633dfa4b768 | 125 | prepareCommand(READ, address); |
| emmibed | 0:1633dfa4b768 | 126 | // _spi.write(0); // dummy cycle, only necessary if READ is replaced by HSREAD |
| emmibed | 0:1633dfa4b768 | 127 | for (int i = 0; i < count; i++) { |
| emmibed | 0:1633dfa4b768 | 128 | buffer[i] = _spi.write(0); |
| emmibed | 0:1633dfa4b768 | 129 | } |
| emmibed | 0:1633dfa4b768 | 130 | deselect(); |
| emmibed | 0:1633dfa4b768 | 131 | } |