Diff: SST25VF.h

Revision:

0:1633dfa4b768

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SST25VF.h	Sun Jan 15 13:51:16 2012 +0000
@@ -0,0 +1,88 @@
+/** SST25VF - drive the Microchip SST25VF Serial Flash using SPI
+*
+* Assumes spi mode is default (8,0).
+*
+* You can clock the SST25VF at up to >20MHz, so it supports the mbed's maximum SPI frequency of 12MHz.
+*/
+
+#include "mbed.h"
+
+/* ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+*  ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+*    Caution: Do not write to adresses where data != 0xFF
+*    Data in selected adress range MUST be 0xFF (See datasheet)
+*  ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+*  ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+*/
+
+#ifndef SST25VF_H
+#define SST25VF_H
+
+#define SPI_FREQ        12000000    // 12Mhz is mbed max (one eight of periph. clock)
+
+#define waitShort() wait_us(10)
+#define waitErase() wait_ms(50)
+
+// command codes for SST25VF
+#define WRITE_STATUS    0x01 // called WRSR in datasheet
+#define WRITE           0x02 // Byte-Program
+#define READ            0x03
+#define WRDI            0x04
+#define READ_STATUS     0x05 // called RDSR 
+#define WREN            0x06
+//#define HSREAD          0x0B // High-Speed-Read
+#define EWSR            0x50 // Enable-Write-Status-Register
+#define CHIP_ERASE      0x60
+#define AAIWRITE        0xAD // word based write
+
+class SST25VF {
+public:
+    /** Create an interface
+    *
+    *
+    * @param spi   An SPI object
+    * @param ncs   Not chip select pin - any free Digital pin will do
+    */
+    SST25VF(SPI& spi, PinName ncs);
+    /** read a byte from SRAM
+    * @param address    The address to read from
+    * @return the character at that address
+    */
+    char read(long int address);
+
+    /** read multiple bytes from SRAM into a buffer
+    * @param address    The SRAM address to read from
+    * @param buffer     The buffer to read into (must be big enough!)
+    * @param count      The number of bytes to read
+    */
+    void read(long int address, char * buffer, int count);
+    /** write a byte to SRAM
+    * @param address    The address SRAM to write to
+    * @param byte       The byte to write there
+    */
+    void write(long int address, char byte);
+    /** write multiple bytes to SRAM from a buffer
+    * @param address    The SRAM address write to
+    * @param buffer     The buffer to write from
+    * @param count      The number of bytes to write
+    */
+    void write(long int address, char * buffer, int count);
+
+
+    void chipErase();
+    char readStatus();
+
+private:
+    SPI& _spi;
+    DigitalOut _ncs;
+
+    void writeStatus(char status);
+    void prepareCommand(char command, long int address);
+    void select();
+    void deselect();
+    void wren();
+    void unlock();
+    void wrdi();
+};
+
+#endif