+
+/**
+ * Read \a _buf lenght \a size byte from data flash memmory.
+ *
+ * \note For read in data flash memory, we
+ * check flag page_modified, if is true (that mean
+ * we had been written a byte in buffer memory) we
+ * flush current page in data flash main memory, and
+ * then read byte from memory, else we read byte
+ * directly from data flash main memory.
+ *
+ * \return the number of bytes read.
+ */