Oleg Evsegneev / FRAMSPI

Interface library for Ramtron FRAM memory, FM25VXX series.

Code sample:

#include "mbed.h"
#include "FRAMSPI.h"

SPI spi(p5,p6,p7);
FRAMSPI fram(spi,p8);
Serial pc(USBTX, USBRX);

int main() {
    char wdata[] = "Hello world!";
    char rdata[14];

    fram.write(0, wdata, 13); // 12 symbols + zero terminator
    fram.read(0, rdata, 13);

    pc.printf("data: %s", rdata);
}

FRAMSPI.h@0:27d10d94f7d9, 2012-10-21 (annotated)

Committer:
Decimus
Date:
Sun Oct 21 17:10:30 2012 +0000
Revision:
0:27d10d94f7d9
Upload

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Decimus 0:27d10d94f7d9 1 /* FRAM_SPI - Ramtron FRAM FM24VXX series driver
Decimus 0:27d10d94f7d9 2 * Copyright (c) 2012 Oleg Evsegneev
Decimus 0:27d10d94f7d9 3 * Released under the MIT License: http://mbed.org/license/mit
Decimus 0:27d10d94f7d9 4 *
Decimus 0:27d10d94f7d9 5 * Datasheet http://www.ramtron.com/files/datasheets/FM25V02_ds.pdf
Decimus 0:27d10d94f7d9 6 */
Decimus 0:27d10d94f7d9 7
Decimus 0:27d10d94f7d9 8 #ifndef FRAMSPI_
Decimus 0:27d10d94f7d9 9 #define FRAMSPI_
Decimus 0:27d10d94f7d9 10
Decimus 0:27d10d94f7d9 11 #include "mbed.h"
Decimus 0:27d10d94f7d9 12
Decimus 0:27d10d94f7d9 13 // commands
Decimus 0:27d10d94f7d9 14 #define READ 0x03
Decimus 0:27d10d94f7d9 15 #define WRITE 0x02
Decimus 0:27d10d94f7d9 16 #define READ_STATUS 0x05 // RDSR
Decimus 0:27d10d94f7d9 17 #define WRITE_ENABLED 0x06 // WREN
Decimus 0:27d10d94f7d9 18 #define WRITE_STATUS 0x01 // WRSR
Decimus 0:27d10d94f7d9 19 #define READ_ID 0x9F // RDID
Decimus 0:27d10d94f7d9 20 #define READ_SN 0xC3 // RSN
Decimus 0:27d10d94f7d9 21
Decimus 0:27d10d94f7d9 22 /** An interface for the Ramtron FM25VXX FRAM over SPI
Decimus 0:27d10d94f7d9 23 *
Decimus 0:27d10d94f7d9 24 *
Decimus 0:27d10d94f7d9 25 *
Decimus 0:27d10d94f7d9 26 * @code
Decimus 0:27d10d94f7d9 27 * #include "mbed.h"
Decimus 0:27d10d94f7d9 28 * #include "FRAMSPI.h"
Decimus 0:27d10d94f7d9 29 *
Decimus 0:27d10d94f7d9 30 * SPI spi(p5,p6,p7);
Decimus 0:27d10d94f7d9 31 * FRAMSPI fram(spi,p8);
Decimus 0:27d10d94f7d9 32 * Serial pc(USBTX, USBRX);
Decimus 0:27d10d94f7d9 33 *
Decimus 0:27d10d94f7d9 34 * int main() {
Decimus 0:27d10d94f7d9 35 * char wdata[] = "Hello world!";
Decimus 0:27d10d94f7d9 36 * char rdata[14];
Decimus 0:27d10d94f7d9 37 *
Decimus 0:27d10d94f7d9 38 * fram.write(0, wdata, 13); // 12 symbols + zero terminator
Decimus 0:27d10d94f7d9 39 * fram.read(0, rdata, 13);
Decimus 0:27d10d94f7d9 40 *
Decimus 0:27d10d94f7d9 41 * pc.printf("data: %s", rdata);
Decimus 0:27d10d94f7d9 42 * }
Decimus 0:27d10d94f7d9 43 * @endcode
Decimus 0:27d10d94f7d9 44 * connections:
Decimus 0:27d10d94f7d9 45 * chip pin 1 to any GPIO. Chip select (!S)
Decimus 0:27d10d94f7d9 46 * chip pin 2 SO to MISO. Write (!W)
Decimus 0:27d10d94f7d9 47 * chip pin 3 to Vout or N/C
Decimus 0:27d10d94f7d9 48 * chip pin 4 to Gnd
Decimus 0:27d10d94f7d9 49 * chip pin 5 SI to MOSI
Decimus 0:27d10d94f7d9 50 * chip pin 6 SCK to sck
Decimus 0:27d10d94f7d9 51 * chip pin 7 to Vout. !Hold
Decimus 0:27d10d94f7d9 52 * chip pin 8 to Vout
Decimus 0:27d10d94f7d9 53 */
Decimus 0:27d10d94f7d9 54
Decimus 0:27d10d94f7d9 55 class FRAMSPI {
Decimus 0:27d10d94f7d9 56
Decimus 0:27d10d94f7d9 57 public:
Decimus 0:27d10d94f7d9 58 /** Create an interface
Decimus 0:27d10d94f7d9 59 *
Decimus 0:27d10d94f7d9 60 * @param spi An SPI object
Decimus 0:27d10d94f7d9 61 * @param ncs Chip select pin
Decimus 0:27d10d94f7d9 62 */
Decimus 0:27d10d94f7d9 63 FRAMSPI(SPI& spi, PinName ncs);
Decimus 0:27d10d94f7d9 64
Decimus 0:27d10d94f7d9 65 /** read chip 8 byte device ID
Decimus 0:27d10d94f7d9 66 */
Decimus 0:27d10d94f7d9 67 void readID(char *buff);
Decimus 0:27d10d94f7d9 68
Decimus 0:27d10d94f7d9 69 /** read chip 2 byte serial number
Decimus 0:27d10d94f7d9 70 */
Decimus 0:27d10d94f7d9 71 void readSN(char *buff);
Decimus 0:27d10d94f7d9 72
Decimus 0:27d10d94f7d9 73 /** read a byte from FRAM
Decimus 0:27d10d94f7d9 74 * @param addr The address to read from
Decimus 0:27d10d94f7d9 75 * @return the byte at that address
Decimus 0:27d10d94f7d9 76 */
Decimus 0:27d10d94f7d9 77 char read(int addr);
Decimus 0:27d10d94f7d9 78
Decimus 0:27d10d94f7d9 79 /** read multiple bytes from FRAM into a buffer
Decimus 0:27d10d94f7d9 80 * @param addr The FRAM address to read from
Decimus 0:27d10d94f7d9 81 * @param buff The buffer to read into (must be big enough!)
Decimus 0:27d10d94f7d9 82 * @param cnt The number of bytes to read
Decimus 0:27d10d94f7d9 83 */
Decimus 0:27d10d94f7d9 84 void read(int addr, char *buff, int cnt);
Decimus 0:27d10d94f7d9 85
Decimus 0:27d10d94f7d9 86 /** write a byte to FRAM
Decimus 0:27d10d94f7d9 87 * @param addr The address SFRAM to write to
Decimus 0:27d10d94f7d9 88 * @param data The byte to write there
Decimus 0:27d10d94f7d9 89 */
Decimus 0:27d10d94f7d9 90 void write(int addr, char data);
Decimus 0:27d10d94f7d9 91
Decimus 0:27d10d94f7d9 92 /** write multiple bytes to FRAM from a buffer
Decimus 0:27d10d94f7d9 93 * @param addr The FRAM address write to
Decimus 0:27d10d94f7d9 94 * @param buff The buffer to write from
Decimus 0:27d10d94f7d9 95 * @param cnt The number of bytes to write
Decimus 0:27d10d94f7d9 96 */
Decimus 0:27d10d94f7d9 97 void write(int addr, char *buff, int cnt);
Decimus 0:27d10d94f7d9 98
Decimus 0:27d10d94f7d9 99 private:
Decimus 0:27d10d94f7d9 100 SPI& _spi;
Decimus 0:27d10d94f7d9 101 DigitalOut _ncs;
Decimus 0:27d10d94f7d9 102 void prepareCommand(char cmd, int addr);
Decimus 0:27d10d94f7d9 103 void select();
Decimus 0:27d10d94f7d9 104 void deselect();
Decimus 0:27d10d94f7d9 105 };
Decimus 0:27d10d94f7d9 106
Decimus 0:27d10d94f7d9 107 #endif