1 files changed, 80 insertions, 0 deletions
diff --git a/aliznayem/spi.c b/aliznayem/spi.c
new file mode 100644
index 0000000..9145109
--- /dev/null
+++ b/aliznayem/spi.c
@@ -0,0 +1,80 @@
+/*
+    Copyright (c) 2007 Stefan Engelke <mbox@stefanengelke.de>
+
+    Permission is hereby granted, free of charge, to any person 
+    obtaining a copy of this software and associated documentation 
+    files (the "Software"), to deal in the Software without 
+    restriction, including without limitation the rights to use, copy, 
+    modify, merge, publish, distribute, sublicense, and/or sell copies 
+    of the Software, and to permit persons to whom the Software is 
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be 
+    included in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
+    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 
+    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 
+    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
+    DEALINGS IN THE SOFTWARE.
+
+    $Id$
+*/
+
+#include <avr/io.h>
+#include "spi.h"
+
+void spi_init()
+// Initialize pins for spi communication
+{
+    SPI_DDR &= ~((1<<MOSI)|(1<<MISO)|(1<<SS)|(1<<SCK));
+    // Define the following pins as output
+    SPI_DDR |= ((1<<MOSI)|(1<<SS)|(1<<SCK));
+
+    
+    SPCR = ((1<<SPE)|               // SPI Enable
+            (0<<SPIE)|              // SPI Interupt Enable
+            (0<<DORD)|              // Data Order (0:MSB first / 1:LSB first)
+            (1<<MSTR)|              // Master/Slave select
+            (0<<SPR1)|(0<<SPR0)|    // SPI Clock Rate
+            (0<<CPOL)|              // Clock Polarity (0:SCK low / 1:SCK hi when idle)
+            (0<<CPHA));             // Clock Phase (0:leading / 1:trailing edge sampling)
+
+    SPSR = (1<<SPI2X);              // Double Clock Rate
+    
+    // SCK frequency 4MHz with above parameters. Deails in datasheet
+    
+}
+
+void spi_transfer_sync (uint8_t * dataout, uint8_t * datain, uint8_t len)
+// Shift full array through target device
+{
+    uint8_t i;
+    for (i = 0; i < len; i++) {
+        SPDR = dataout[i];
+        while((SPSR & (1<<SPIF))==0);
+        datain[i] = SPDR;
+    }
+}
+
+void spi_transmit_sync (uint8_t * dataout, uint8_t len)
+// Shift full array to target device without receiving any byte
+{
+    uint8_t i;
+    for (i = 0; i < len; i++) {
+        SPDR = dataout[i];
+        while((SPSR & (1<<SPIF))==0);
+    }
+}
+
+uint8_t spi_fast_shift (uint8_t data)
+// Clocks only one byte to target device and returns the received one
+{
+    SPDR = data;
+    while((SPSR & (1<<SPIF))==0);
+    return SPDR;
+}
+