Ser25lcxxx.h

00001 /*
00002 * Ser25lcxxx library
00003 * Copyright (c) 2010 Hendrik Lipka
00004 * 
00005 * Permission is hereby granted, free of charge, to any person obtaining a copy
00006 * of this software and associated documentation files (the "Software"), to deal
00007 * in the Software without restriction, including without limitation the rights
00008 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00009 * copies of the Software, and to permit persons to whom the Software is
00010 * furnished to do so, subject to the following conditions:
00011 * 
00012 * The above copyright notice and this permission notice shall be included in
00013 * all copies or substantial portions of the Software.
00014 * 
00015 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00016 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00017 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00018 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00019 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00020 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00021 * THE SOFTWARE.
00022 */
00023 
00024 #ifndef __SER25LCXXX_H__
00025 #define __SER25LCXXX_H__
00026 
00027 #include "mbed.h"
00028 
00029 
00030 #define EEPROM_CMD_READ     0x03
00031 #define EEPROM_CMD_WRITE    0x02
00032 #define EEPROM_CMD_WRDI     0x04
00033 #define EEPROM_CMD_WREN     0x06
00034 #define EEPROM_CMD_RDSR     0x05
00035 #define EEPROM_CMD_WRSR     0x01
00036 
00037 
00038 #define EEPROM_SPI_SPEED    1000000
00039 
00040 #define EEPROM_CLEAN_BYTE   0xff
00041 
00042 
00043 /**
00044 A class to read and write all 25* serial SPI eeprom devices from Microchip
00045 (from 25xx010 to 25xx1024).
00046 
00047 One needs to provide total size and page size, since this cannot be read from
00048 the devices, and the page size differs even by constant size (look up the data
00049 sheet for your part!)
00050 */
00051 class Ser25LCxxx
00052 {
00053     public:
00054     
00055         /**
00056             Create the handler class
00057             
00058             @param sck clock pin of the spi where the eeprom is connected
00059             @param si input pin of the spi where the eeprom is connected
00060             @param so output pin of the spi where the eeprom is connected
00061             @param enable the pin name for the port where /CS is connected
00062             @param pagenumber number of pages
00063             @param pagesize the size of each page
00064         */
00065         Ser25LCxxx(PinName sck, PinName si, PinName so, PinName enable,
00066                                                 int pagenumber, int pagesize);
00067         
00068         /**
00069             Destroy the handler
00070         */
00071         ~Ser25LCxxx() {};
00072         
00073         /**
00074             Read from the eeprom memory
00075             
00076             @param startAdr the adress where to start reading
00077             @param len the number of bytes to read
00078             @param buf destination buffer
00079             @return number of read bytes
00080         */
00081         unsigned int read(unsigned int startAdr, unsigned int len,
00082                                                         unsigned char* buf);
00083         
00084         /**
00085             Writes the give buffer into the eeprom memory
00086 
00087             @param startAdr the eeprom adress where to start writing (it 
00088                                         doesn't have to match a page boundary)
00089             @param len number of bytes to write
00090             @param data data to write
00091             @return the number of written bytes
00092         */
00093         unsigned int write(unsigned int startAdr, unsigned int len,
00094                                                     const unsigned char* data);
00095         
00096         /**
00097             Fills the given page with EEPROM_CLEAN_BYTE
00098 
00099             @param pageNum the page to clear
00100             @return the number of written bytes (it should be the page size)
00101         */
00102         unsigned int clearPage(unsigned int pageNum);
00103         
00104         /**
00105             Fills the whole eeprom with EEPROM_CLEAN_BYTE
00106             
00107             @return the number of written bytes (it should be the eeprom size)
00108         */
00109         unsigned int clearMem();
00110 
00111         /**
00112             Return TRUE if a write is performing
00113         */
00114         bool isWriteInProgress() {
00115             return (readStatus()&0x01)!=0x00;
00116         }
00117 
00118         /**
00119             Return TRUE if the entire eeprom memory is writable
00120         */
00121         bool isFullyWritable() {
00122             return (readStatus()&0x0C)==0x00;
00123         }
00124 
00125         /**
00126             Return TRUE if only the first half of the eeprom memory is writable
00127         */
00128         bool isHalfWritable() {
00129             return (readStatus()&0x0C)==0x08;
00130         }
00131 
00132         /**
00133             Return TRUE if the eeprom memory is not writable
00134         */
00135         bool isNotWritable() {
00136             return (readStatus()&0x0C)==0x0C;
00137         }
00138 
00139         /**
00140             Set the eeprom memory not writable
00141         */
00142         void setNotWritable () {
00143             writeStatus(0x0C);
00144         }
00145 
00146         /**
00147             Set the eeprom memory fully writable
00148         */
00149         void setFullyWritable () {
00150             writeStatus(0x00);
00151         }
00152         
00153         /**
00154             Set only the first half of the eeprom memory as writable
00155         */
00156         void setHalfWritable() {
00157             writeStatus(0x08);
00158         }
00159 
00160     private:
00161     
00162         /**
00163             Write data within an eeprom page
00164             
00165             @param startAdr destination address of the eeprm memory
00166             @param len number of bytes to write
00167             @param data data to be written in the eeprom memory
00168             @return number of written bytes
00169         */
00170         unsigned int writePage(unsigned int startAdr, unsigned int len,
00171                                                     const unsigned char* data);
00172                                                     
00173         /**
00174             Read the status register of the eeprom memory
00175             
00176             @return status register
00177         */
00178         int readStatus();
00179         
00180         /**
00181             Write the status register
00182             
00183             @param val status register
00184         */
00185         void writeStatus(unsigned char val);
00186 
00187         /**
00188             Wait until a write procedure ends or an interval of 5ms is expired
00189             
00190             @return TRUE if the write procedure has successfully terminated,
00191                 FALSE if the interval is expired
00192         */
00193         bool waitForWrite();
00194         
00195         /**
00196             Enable the write procedure
00197         */
00198         void enableWrite();
00199 
00200         SPI spi;
00201         DigitalOut cs;
00202         int size;
00203         int pageSize;
00204         int pageNumber;
00205 };
00206 
00207 #endif