Diff: Hotboards_eeprom.cpp

Revision:

0:38fad00cc45b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Hotboards_eeprom.cpp	Fri Jan 29 00:46:08 2016 +0000
@@ -0,0 +1,209 @@
+/*
+  Hotboards_eeprom.cpp - Driver to control serial (spi) eeprom memories, The memories are
+  compatibles amount the manufactures Microchip, Atmel and ST, and of course you can control
+  Hotboards eeprom board (http://hotboards.org)
+  Created by Diego Perez, January 16, 2016.
+  Released into the public domain.
+  
+  Density:   1Kbit   | 2Kbit   | 4Kbit   | 8Kbit   | 16Kbit  | 32Kbit  | 64Kbit  | 128Kbit | 256Kbit | 512Kbit | 1 Mbit
+  Part:      25xx010 | 25xx020 | 25xx040 | 25xx080 | 25xx160 | 25xx320 | 25xx640 | 25xx128 | 25xx256 | 25xx512 | 25xx1024
+  Page/Byte: 16      | 16      | 16      | 16(32)  | 16(32)  | 32      | 32      | 64      | 64      | 128     | 256
+  Addr/Bits: 7       | 8       | 9       | 16      | 16      | 16      | 16      | 16      | 16      | 16 
+*/
+#include "Hotboards_eeprom.h"
+
+#define READ     0x03
+#define WRITE    0x02
+#define WRDI     0x04
+#define WREN     0x06
+#define RDSR     0x05
+#define WRSR     0x01
+
+const uint16_t PageSize[ ] = { 16, 16, 16, 16, 32, 32, 64, 64, 128, 256 };
+const uint32_t EepromSize[ ] = { 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072 };
+
+Hotboards_eeprom::Hotboards_eeprom( SPI &spi, PinName cs, uint8_t type )
+    : _spi(spi), _cs_pin(cs) 
+{
+    _cs_pin = cs;
+    _type = type;
+    _page = PageSize[ type ];
+    _density = EepromSize[ type ];
+}
+
+/*
+ * just make sure the Cs pin is not clear
+ */
+void Hotboards_eeprom::init( void )
+{
+   _cs_pin = 1; 
+}
+
+/*
+ * write a single byte in a given eeprom address, this operation will take 5ms
+ * address: eeprom address where tha byte will be written
+ * data: the byte that will be written at the given address 
+ */
+void Hotboards_eeprom::write( uint32_t address, uint8_t data )
+{
+    write( address, &data, 1 );
+}
+
+/*
+ * write a given number of bytes into the eeprom atarting at a given address
+ * address: eeprom address where tha byte will be written
+ * data: pointer to array of bytes that need to be written
+ * size: the number of bytes to write 
+ */
+void Hotboards_eeprom::write( uint32_t address, uint8_t *data, uint16_t size )
+{
+    uint16_t temp;
+    /* just to cover your ass, check if the address is a valid direction */
+    if( ( address < _density ) && ( size != 0 ) )
+    {
+        /* check if the amount of bytes to be read from the requested address do not exced the eeprom
+        memory map if so, then only read the bytes left*/
+        if( ( address + size ) > _density )
+        {
+            size = _density - address;
+        }
+
+        /* Check how many bytes are left to be written within a single page */
+        temp = _page - ( address % _page );
+        if( temp >= size  )
+        {
+            /* Data lenght can be written witihn the current page */
+            writePage( address, data, size );
+        }
+        else
+        {
+            /* Data can not be written within the current page, so write only the bytes left */
+            writePage( address, data, temp );
+            /* update pointer to data, lenght and addres */
+            data = data + temp;
+            size = size - temp;
+            address = address + temp;
+                
+            /* Check if the remaining data is bigger than a page size */
+            while( size > _page )
+            {
+                /* Write an entire page into eeprom */
+                writePage( address, data, _page );
+                size = size - _page;
+                data = data + _page;
+                address = address + _page;
+            }
+            /* Write one last time if there is still data to be written */
+            if( size != 0 )
+            {
+                writePage( address, data, size );
+            }
+        }
+    } 
+}
+
+/*
+ * read a single byte from a given eeprom address
+ * address: eeprom address where the byte will be read
+ */
+uint8_t Hotboards_eeprom::read( uint32_t address )
+{
+    uint8_t data;
+    read( address, &data, 1 );
+    return data;  
+}
+
+/*
+ * read a given number of bytes from the eeprom starting at a given address
+ * address: eeprom address where the bytes will be read it
+ * data: pointer to array where data will be stored
+ * size: the number of bytes to read 
+ */
+void Hotboards_eeprom::read( uint32_t address, uint8_t *data, uint16_t size )
+{
+    uint16_t i;
+    /* just to cover your ass, check if the address is a valid direction */
+    if( ( address < _density ) && ( size != 0 ) )
+    {
+        /* check if the amount of bytes to be read from the requested address do not exced the eeprom
+        memory map if so, then only read the bytes left*/
+        if( ( address + size ) > _density )
+        {
+            size = _density - address;
+        }
+        
+        /* operation begins, select memory */
+        _cs_pin = 0;
+        
+        /* Send command Read and address, depend on device is the number of address bytes neccesary */
+        sendAddress( READ, address );
+
+        for( i = 0 ; i<size ; i++ )
+        {
+            /* Read data from memory */
+            *data = _spi.write( 0xAA );
+            data++;
+        };
+        /* operation ended, unselect memory */
+        _cs_pin = 1;
+    }
+}
+
+void Hotboards_eeprom::sendAddress( uint8_t cmd, uint32_t address )
+{
+    if( _type < HT_EEPROM25xx_4Kb )
+    {
+        /* Send the command and one byte address */
+        _spi.write( cmd );
+        _spi.write( address );
+    }
+    else if( _type == HT_EEPROM25xx_4Kb )
+    {
+        /* Send the command coded in the MSB of the address and one LSB address */
+        _spi.write( cmd | ( uint8_t )( address >> 8 ) );
+        _spi.write( ( uint8_t )address );
+    }
+    else if( ( _type > HT_EEPROM25xx_4Kb ) && ( _type < HT_EEPROM25xx_1Mb ) )
+    {
+        /* Send command plus two byte address */
+        _spi.write( cmd );
+        _spi.write( ( uint8_t )( address >> 8 ) );
+        _spi.write( ( uint8_t )address );
+    }
+    else if( _type == HT_EEPROM25xx_1Mb )
+    {
+        /* Send command plus three byte address */
+        _spi.write( cmd );
+        _spi.write( ( uint8_t )( address >> 16 ) );
+        _spi.write( ( uint8_t )( address >> 8 ) );
+        _spi.write( ( uint8_t )address );
+    }
+}
+
+void Hotboards_eeprom::writePage( uint32_t address, uint8_t *data, uint16_t size )
+{
+    uint16_t i;
+
+    /* Select memory */
+    _cs_pin = 0;  
+    /* write eneable latch */
+    _spi.write( WREN );
+    /* Unselect eeprom */
+    _cs_pin = 1;    
+    
+    /* Select memory */
+    _cs_pin = 0;  
+    /* Send comand write and address, depend on device is the number of address bytes neccesary */
+    sendAddress( WRITE, address );
+    /* Send data to eeprom */
+    for( i = 0 ; i<size ; i++ )
+    {
+        /* Read data from memory */
+        _spi.write( *data );
+        data++;
+    };
+    /* Unselect eeprom */
+    _cs_pin = 1;  
+    /* wait until data has been recorded */
+    wait( 0.006 );  
+}