Diff: Ser25lcxxx.cpp

Revision:

0:238ca4fdef8c

Child:

1:c29a67c7034d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Ser25lcxxx.cpp	Wed Jan 26 22:14:41 2011 +0000
@@ -0,0 +1,177 @@
+#include "Ser25lcxxx.h"
+#include "wait_api.h"
+
+#define HIGH(x) ((x&0xff00)>>8)
+#define LOW(x) (x&0xff)
+
+Ser25LCxxx::Ser25LCxxx(SPI *spi, PinName enable, int bytes, int pagesize) {
+    _spi=spi;
+    _enable=new DigitalOut(enable);
+    _size=bytes;
+    _pageSize=pagesize;
+    _enable->write(1);
+}
+
+Ser25LCxxx::~Ser25LCxxx() {
+    delete _enable;
+}
+
+char* Ser25LCxxx::read(unsigned int startAdr, unsigned int len) {
+    // assertion
+    if (startAdr+len>_size)
+        return NULL;
+    char* ret=(char*)malloc(len);
+    _enable->write(0);
+    wait_us(1);
+    // send address
+    if (_size<512) { // 256 and 128 bytes
+        _spi->write(0x03);
+        _spi->write(LOW(startAdr));
+    } else if (512==_size) { // 4k variant adds 9th address bit to command
+        _spi->write(startAdr>255?0xb:0x3);
+        _spi->write(LOW(startAdr));
+    } else if (_size<131072) { // everything up to 512k
+        _spi->write(0x03);
+        _spi->write(HIGH(startAdr));
+        _spi->write(LOW(startAdr));
+    } else { // 25xx1024, needs 3 byte address
+        _spi->write(0x03);
+        _spi->write(startAdr>>16);
+        _spi->write(HIGH(startAdr));
+        _spi->write(LOW(startAdr));
+    }
+    // read data into buffer
+    for (int i=0;i<len;i++) {
+        ret[i]=_spi->write(0);
+    }
+    wait_us(1);
+    _enable->write(1);
+    return ret;
+}
+
+bool Ser25LCxxx::write(unsigned int startAdr, unsigned int len, const char* data) {
+    if (startAdr+len>_size)
+        return -1;
+
+    int ofs=0;
+    while (ofs<len) {
+        // calculate amount of data to write into current page
+        int pageLen=_pageSize-((startAdr+ofs)%_pageSize);
+        if (ofs+pageLen>len)
+            pageLen=len-ofs;
+        // write single page
+        bool b=writePage(startAdr+ofs,pageLen,data+ofs);
+        if (!b)
+            return false;
+        // and switch to next page
+        ofs+=pageLen;
+    }
+    return true;
+}
+
+bool Ser25LCxxx::writePage(unsigned int startAdr, unsigned int len, const char* data) {
+    enableWrite();
+
+    _enable->write(0);
+    wait_us(1);
+
+    if (_size<512) { // 256 and 128 bytes
+        _spi->write(0x02);
+        _spi->write(LOW(startAdr));
+    } else if (512==_size) { // 4k variant adds 9th address bit to command
+        _spi->write(startAdr>255?0xa:0x2);
+        _spi->write(LOW(startAdr));
+    } else if (_size<131072) { // everything up to 512k
+        _spi->write(0x02);
+        _spi->write(HIGH(startAdr));
+        _spi->write(LOW(startAdr));
+    } else { // 25xx1024, needs 3 byte address
+        _spi->write(0x02);
+        _spi->write(startAdr>>16);
+        _spi->write(HIGH(startAdr));
+        _spi->write(LOW(startAdr));
+    }
+
+    // do real write
+    for (int i=0;i<len;i++) {
+        _spi->write(data[i]);
+    }
+    wait_us(1);
+    // disable to start physical write
+    _enable->write(1);
+    
+    waitForWrite();
+
+    return true;
+}
+
+bool Ser25LCxxx::clearPage(unsigned int pageNum) {
+    enableWrite();
+    if (_size<65535) {
+        char* s=(char*)malloc(_pageSize);
+        for (int i=0;i<_pageSize;i++) {
+            s[i]=0xff;
+        }
+        bool b=writePage(_pageSize*pageNum,_pageSize,s);
+        delete s;
+        return b;
+    } else {
+        _enable->write(0);
+        wait_us(1);
+        _spi->write(0x42);
+        _spi->write(HIGH(_pageSize*pageNum));
+        _spi->write(LOW(_pageSize*pageNum));
+        wait_us(1);
+        _enable->write(1);
+
+        waitForWrite();
+    }
+    return true;
+}
+
+void Ser25LCxxx::clearMem() {
+    enableWrite();
+    if (_size<65535) {
+        for (int i=0;i<_size/_pageSize;i++) {
+            if (!clearPage(i))
+                break;
+        }
+    }
+    else
+    {
+        _enable->write(0);
+        wait_us(1);
+        _spi->write(0xc7);
+        wait_us(1);
+        _enable->write(1);
+
+        waitForWrite();
+    }
+}
+
+int Ser25LCxxx::readStatus() {
+    _enable->write(0);
+    wait_us(1);
+    _spi->write(0x5);
+    int status=_spi->write(0x00);
+    wait_us(1);
+    _enable->write(1);
+    return status;
+}
+
+void Ser25LCxxx::waitForWrite() {
+    while (true) {
+        if (0==readStatus()&1)
+            break;
+        wait_us(10);
+    }
+}
+
+void Ser25LCxxx::enableWrite()
+{
+    _enable->write(0);
+    wait_us(1);
+    _spi->write(0x06);
+    wait_us(1);
+    _enable->write(1);
+}