Hendrik Lipka / 25LCxxx_SPI

A library to read and write all 25* serial SPI eeprom devices from Microchip (from 25xx010 to 25xx1024).

Dependents:   RobotRic VITI2_ihm_2

Ser25lcxxx.cpp@1:c29a67c7034d, 2011-02-03 (annotated)

Committer:
hlipka
Date:
Thu Feb 03 20:31:08 2011 +0000
Revision:
1:c29a67c7034d
Parent:
0:238ca4fdef8c
Child:
2:3a3404dbd3eb
bugfix: clearPage did hang with 25LC1024

Who changed what in which revision?

UserRevisionLine numberNew contents of line
hlipka 0:238ca4fdef8c 1 #include "Ser25lcxxx.h"
hlipka 0:238ca4fdef8c 2 #include "wait_api.h"
hlipka 0:238ca4fdef8c 3
hlipka 0:238ca4fdef8c 4 #define HIGH(x) ((x&0xff00)>>8)
hlipka 0:238ca4fdef8c 5 #define LOW(x) (x&0xff)
hlipka 0:238ca4fdef8c 6
hlipka 0:238ca4fdef8c 7 Ser25LCxxx::Ser25LCxxx(SPI *spi, PinName enable, int bytes, int pagesize) {
hlipka 0:238ca4fdef8c 8 _spi=spi;
hlipka 0:238ca4fdef8c 9 _enable=new DigitalOut(enable);
hlipka 0:238ca4fdef8c 10 _size=bytes;
hlipka 0:238ca4fdef8c 11 _pageSize=pagesize;
hlipka 0:238ca4fdef8c 12 _enable->write(1);
hlipka 0:238ca4fdef8c 13 }
hlipka 0:238ca4fdef8c 14
hlipka 0:238ca4fdef8c 15 Ser25LCxxx::~Ser25LCxxx() {
hlipka 0:238ca4fdef8c 16 delete _enable;
hlipka 0:238ca4fdef8c 17 }
hlipka 0:238ca4fdef8c 18
hlipka 0:238ca4fdef8c 19 char* Ser25LCxxx::read(unsigned int startAdr, unsigned int len) {
hlipka 0:238ca4fdef8c 20 // assertion
hlipka 0:238ca4fdef8c 21 if (startAdr+len>_size)
hlipka 0:238ca4fdef8c 22 return NULL;
hlipka 0:238ca4fdef8c 23 char* ret=(char*)malloc(len);
hlipka 0:238ca4fdef8c 24 _enable->write(0);
hlipka 0:238ca4fdef8c 25 wait_us(1);
hlipka 0:238ca4fdef8c 26 // send address
hlipka 0:238ca4fdef8c 27 if (_size<512) { // 256 and 128 bytes
hlipka 0:238ca4fdef8c 28 _spi->write(0x03);
hlipka 0:238ca4fdef8c 29 _spi->write(LOW(startAdr));
hlipka 0:238ca4fdef8c 30 } else if (512==_size) { // 4k variant adds 9th address bit to command
hlipka 0:238ca4fdef8c 31 _spi->write(startAdr>255?0xb:0x3);
hlipka 0:238ca4fdef8c 32 _spi->write(LOW(startAdr));
hlipka 0:238ca4fdef8c 33 } else if (_size<131072) { // everything up to 512k
hlipka 0:238ca4fdef8c 34 _spi->write(0x03);
hlipka 0:238ca4fdef8c 35 _spi->write(HIGH(startAdr));
hlipka 0:238ca4fdef8c 36 _spi->write(LOW(startAdr));
hlipka 0:238ca4fdef8c 37 } else { // 25xx1024, needs 3 byte address
hlipka 0:238ca4fdef8c 38 _spi->write(0x03);
hlipka 0:238ca4fdef8c 39 _spi->write(startAdr>>16);
hlipka 0:238ca4fdef8c 40 _spi->write(HIGH(startAdr));
hlipka 0:238ca4fdef8c 41 _spi->write(LOW(startAdr));
hlipka 0:238ca4fdef8c 42 }
hlipka 0:238ca4fdef8c 43 // read data into buffer
hlipka 0:238ca4fdef8c 44 for (int i=0;i<len;i++) {
hlipka 0:238ca4fdef8c 45 ret[i]=_spi->write(0);
hlipka 0:238ca4fdef8c 46 }
hlipka 0:238ca4fdef8c 47 wait_us(1);
hlipka 0:238ca4fdef8c 48 _enable->write(1);
hlipka 0:238ca4fdef8c 49 return ret;
hlipka 0:238ca4fdef8c 50 }
hlipka 0:238ca4fdef8c 51
hlipka 0:238ca4fdef8c 52 bool Ser25LCxxx::write(unsigned int startAdr, unsigned int len, const char* data) {
hlipka 0:238ca4fdef8c 53 if (startAdr+len>_size)
hlipka 0:238ca4fdef8c 54 return -1;
hlipka 0:238ca4fdef8c 55
hlipka 0:238ca4fdef8c 56 int ofs=0;
hlipka 0:238ca4fdef8c 57 while (ofs<len) {
hlipka 0:238ca4fdef8c 58 // calculate amount of data to write into current page
hlipka 0:238ca4fdef8c 59 int pageLen=_pageSize-((startAdr+ofs)%_pageSize);
hlipka 0:238ca4fdef8c 60 if (ofs+pageLen>len)
hlipka 0:238ca4fdef8c 61 pageLen=len-ofs;
hlipka 0:238ca4fdef8c 62 // write single page
hlipka 0:238ca4fdef8c 63 bool b=writePage(startAdr+ofs,pageLen,data+ofs);
hlipka 0:238ca4fdef8c 64 if (!b)
hlipka 0:238ca4fdef8c 65 return false;
hlipka 0:238ca4fdef8c 66 // and switch to next page
hlipka 0:238ca4fdef8c 67 ofs+=pageLen;
hlipka 0:238ca4fdef8c 68 }
hlipka 0:238ca4fdef8c 69 return true;
hlipka 0:238ca4fdef8c 70 }
hlipka 0:238ca4fdef8c 71
hlipka 0:238ca4fdef8c 72 bool Ser25LCxxx::writePage(unsigned int startAdr, unsigned int len, const char* data) {
hlipka 0:238ca4fdef8c 73 enableWrite();
hlipka 0:238ca4fdef8c 74
hlipka 0:238ca4fdef8c 75 _enable->write(0);
hlipka 0:238ca4fdef8c 76 wait_us(1);
hlipka 0:238ca4fdef8c 77
hlipka 0:238ca4fdef8c 78 if (_size<512) { // 256 and 128 bytes
hlipka 0:238ca4fdef8c 79 _spi->write(0x02);
hlipka 0:238ca4fdef8c 80 _spi->write(LOW(startAdr));
hlipka 0:238ca4fdef8c 81 } else if (512==_size) { // 4k variant adds 9th address bit to command
hlipka 0:238ca4fdef8c 82 _spi->write(startAdr>255?0xa:0x2);
hlipka 0:238ca4fdef8c 83 _spi->write(LOW(startAdr));
hlipka 0:238ca4fdef8c 84 } else if (_size<131072) { // everything up to 512k
hlipka 0:238ca4fdef8c 85 _spi->write(0x02);
hlipka 0:238ca4fdef8c 86 _spi->write(HIGH(startAdr));
hlipka 0:238ca4fdef8c 87 _spi->write(LOW(startAdr));
hlipka 0:238ca4fdef8c 88 } else { // 25xx1024, needs 3 byte address
hlipka 0:238ca4fdef8c 89 _spi->write(0x02);
hlipka 0:238ca4fdef8c 90 _spi->write(startAdr>>16);
hlipka 0:238ca4fdef8c 91 _spi->write(HIGH(startAdr));
hlipka 0:238ca4fdef8c 92 _spi->write(LOW(startAdr));
hlipka 0:238ca4fdef8c 93 }
hlipka 0:238ca4fdef8c 94
hlipka 0:238ca4fdef8c 95 // do real write
hlipka 0:238ca4fdef8c 96 for (int i=0;i<len;i++) {
hlipka 0:238ca4fdef8c 97 _spi->write(data[i]);
hlipka 0:238ca4fdef8c 98 }
hlipka 0:238ca4fdef8c 99 wait_us(1);
hlipka 0:238ca4fdef8c 100 // disable to start physical write
hlipka 0:238ca4fdef8c 101 _enable->write(1);
hlipka 0:238ca4fdef8c 102
hlipka 0:238ca4fdef8c 103 waitForWrite();
hlipka 0:238ca4fdef8c 104
hlipka 0:238ca4fdef8c 105 return true;
hlipka 0:238ca4fdef8c 106 }
hlipka 0:238ca4fdef8c 107
hlipka 0:238ca4fdef8c 108 bool Ser25LCxxx::clearPage(unsigned int pageNum) {
hlipka 0:238ca4fdef8c 109 enableWrite();
hlipka 0:238ca4fdef8c 110 if (_size<65535) {
hlipka 0:238ca4fdef8c 111 char* s=(char*)malloc(_pageSize);
hlipka 0:238ca4fdef8c 112 for (int i=0;i<_pageSize;i++) {
hlipka 0:238ca4fdef8c 113 s[i]=0xff;
hlipka 0:238ca4fdef8c 114 }
hlipka 0:238ca4fdef8c 115 bool b=writePage(_pageSize*pageNum,_pageSize,s);
hlipka 0:238ca4fdef8c 116 delete s;
hlipka 0:238ca4fdef8c 117 return b;
hlipka 1:c29a67c7034d 118 } else if (_size<131072) { // everything up to 512k
hlipka 0:238ca4fdef8c 119 _enable->write(0);
hlipka 0:238ca4fdef8c 120 wait_us(1);
hlipka 0:238ca4fdef8c 121 _spi->write(0x42);
hlipka 0:238ca4fdef8c 122 _spi->write(HIGH(_pageSize*pageNum));
hlipka 0:238ca4fdef8c 123 _spi->write(LOW(_pageSize*pageNum));
hlipka 0:238ca4fdef8c 124 wait_us(1);
hlipka 0:238ca4fdef8c 125 _enable->write(1);
hlipka 0:238ca4fdef8c 126
hlipka 0:238ca4fdef8c 127 waitForWrite();
hlipka 1:c29a67c7034d 128 } else { // 25xx1024, needs 3 byte address
hlipka 1:c29a67c7034d 129 _enable->write(0);
hlipka 1:c29a67c7034d 130 wait_us(1);
hlipka 1:c29a67c7034d 131 _spi->write(0x42);
hlipka 1:c29a67c7034d 132 _spi->write((_pageSize*pageNum)>>16);
hlipka 1:c29a67c7034d 133 _spi->write(HIGH(_pageSize*pageNum));
hlipka 1:c29a67c7034d 134 _spi->write(LOW(_pageSize*pageNum));
hlipka 1:c29a67c7034d 135 wait_us(1);
hlipka 1:c29a67c7034d 136 _enable->write(1);
hlipka 1:c29a67c7034d 137
hlipka 1:c29a67c7034d 138 waitForWrite();
hlipka 0:238ca4fdef8c 139 }
hlipka 1:c29a67c7034d 140
hlipka 1:c29a67c7034d 141
hlipka 0:238ca4fdef8c 142 return true;
hlipka 0:238ca4fdef8c 143 }
hlipka 0:238ca4fdef8c 144
hlipka 0:238ca4fdef8c 145 void Ser25LCxxx::clearMem() {
hlipka 0:238ca4fdef8c 146 enableWrite();
hlipka 0:238ca4fdef8c 147 if (_size<65535) {
hlipka 0:238ca4fdef8c 148 for (int i=0;i<_size/_pageSize;i++) {
hlipka 0:238ca4fdef8c 149 if (!clearPage(i))
hlipka 0:238ca4fdef8c 150 break;
hlipka 0:238ca4fdef8c 151 }
hlipka 0:238ca4fdef8c 152 }
hlipka 0:238ca4fdef8c 153 else
hlipka 0:238ca4fdef8c 154 {
hlipka 0:238ca4fdef8c 155 _enable->write(0);
hlipka 0:238ca4fdef8c 156 wait_us(1);
hlipka 0:238ca4fdef8c 157 _spi->write(0xc7);
hlipka 0:238ca4fdef8c 158 wait_us(1);
hlipka 0:238ca4fdef8c 159 _enable->write(1);
hlipka 0:238ca4fdef8c 160
hlipka 0:238ca4fdef8c 161 waitForWrite();
hlipka 0:238ca4fdef8c 162 }
hlipka 0:238ca4fdef8c 163 }
hlipka 0:238ca4fdef8c 164
hlipka 0:238ca4fdef8c 165 int Ser25LCxxx::readStatus() {
hlipka 0:238ca4fdef8c 166 _enable->write(0);
hlipka 0:238ca4fdef8c 167 wait_us(1);
hlipka 0:238ca4fdef8c 168 _spi->write(0x5);
hlipka 0:238ca4fdef8c 169 int status=_spi->write(0x00);
hlipka 0:238ca4fdef8c 170 wait_us(1);
hlipka 0:238ca4fdef8c 171 _enable->write(1);
hlipka 0:238ca4fdef8c 172 return status;
hlipka 0:238ca4fdef8c 173 }
hlipka 0:238ca4fdef8c 174
hlipka 0:238ca4fdef8c 175 void Ser25LCxxx::waitForWrite() {
hlipka 0:238ca4fdef8c 176 while (true) {
hlipka 0:238ca4fdef8c 177 if (0==readStatus()&1)
hlipka 0:238ca4fdef8c 178 break;
hlipka 0:238ca4fdef8c 179 wait_us(10);
hlipka 0:238ca4fdef8c 180 }
hlipka 0:238ca4fdef8c 181 }
hlipka 0:238ca4fdef8c 182
hlipka 0:238ca4fdef8c 183 void Ser25LCxxx::enableWrite()
hlipka 0:238ca4fdef8c 184 {
hlipka 0:238ca4fdef8c 185 _enable->write(0);
hlipka 0:238ca4fdef8c 186 wait_us(1);
hlipka 0:238ca4fdef8c 187 _spi->write(0x06);
hlipka 0:238ca4fdef8c 188 wait_us(1);
hlipka 0:238ca4fdef8c 189 _enable->write(1);
hlipka 0:238ca4fdef8c 190 }