Diff: PRAM.cpp

Revision:

1:2aeba027f61e

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PRAM.cpp	Tue Dec 11 02:12:14 2012 +0000
@@ -0,0 +1,79 @@
+#include "mbed.h"
+#include "PRAM.h"
+
+
+PRAM::PRAM (SPI &spi, PinName cs) : _spi(spi), _cs(cs) {
+    int i;
+
+    _cs = 1;
+    _spi.frequency(16000000);
+    wait_ms(10);
+    
+    _cs = 0;
+    _spi.write(CMD_RDID);
+    printf("RAM Manufacturer ID : %02x\r\n", spi.write(0));
+    i = (spi.write(0) << 8) | spi.write(0);
+    printf("RAM Device ID : %04x\r\n", i);
+    _cs = 1;
+}
+
+PRAM::PRAM (PinName mosi, PinName miso, PinName sclk, PinName cs) : _spi(mosi, miso, sclk), _cs(cs) {
+}
+
+int PRAM::status () {
+    int r;
+
+    _cs = 0;
+    _spi.write(CMD_RDSR);
+    r = _spi.write(0);
+    _cs = 1;
+    return r;
+}
+
+int PRAM::write (int addr, char *buf, int len) {
+    int i;
+
+    while (status() & 1) {
+        // write in progress
+        wait_us(1);
+    }
+
+    _cs = 0;
+    _spi.write(CMD_WREN);
+    _cs = 1;
+    wait_us(1);
+
+    _cs = 0;
+    _spi.write(CMD_PP_BA);
+    _spi.write((addr >> 16) & 0xff);
+    _spi.write((addr >> 8) & 0xff);
+    _spi.write(addr & 0xff);
+
+    len = len - (addr & 0x3f);
+    for (i = 0; i < len; i ++) {
+        _spi.write(buf[i]);
+    }
+    _cs = 1;
+    return i;
+}
+
+int PRAM::read (int addr, char *buf, int len) {
+    int i;
+
+    while (status() & 1) {
+        // write in progress
+        wait_us(1);
+    }
+
+    _cs = 0;
+    _spi.write(CMD_READ);
+    _spi.write((addr >> 16) & 0xff);
+    _spi.write((addr >> 8) & 0xff);
+    _spi.write(addr & 0xff);
+
+    for (i = 0; i < len; i ++) {
+        buf[i] = _spi.write(0);
+    }
+    _cs = 1;
+    return i;
+}