diff --git a/se/sics/mspsim/chip/CC2520SPI.java b/se/sics/mspsim/chip/CC2520SPI.java
new file mode 100644
index 0000000..f8a33ee
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+++ b/se/sics/mspsim/chip/CC2520SPI.java
@@ -0,0 +1,77 @@
+package se.sics.mspsim.chip;
+
+public class CC2520SPI {
+    SPICommand[] spiCommands = {
+            new SPICommand("SNOP 0 0 0 0 0 0 0 0"),
+            new SPICommand("IBUFLD 0 0 0 0 0 0 1 0 i i i i i i i i"),
+            new SPICommand("SIBUFEX 0 0 0 0 0 0 1 1"),
+            new SPICommand("SSAMPLECCA 0 0 0 0 0 1 0 0"),
+            new SPICommand("SRES 0 0 0 0 1 1 1 1 - - - - - - - -"),
+            new SPICommand("MEMRD 0 0 0 1 a a a a a a a a a a a a - - - - - - - - ..."),
+            new SPICommand("MEMWR 0 0 1 0 a a a a a a a a a a a a d d d d d d d d ..."),
+            new SPICommand("RXBUF 0 0 1 1 0 0 0 0 - - - - - - - - ..."),
+            new SPICommand("RXBUFCP 0 0 1 1 1 0 0 0 0 0 0 0 a a a a a a a a a a a a - - - - - - - - ..."),
+            new SPICommand("RXBUFMOV 0 0 1 1 0 0 1 p c c c c c c c c 0 0 0 0 a a a a a a a a a a a a"),
+            new SPICommand("TXBUF 0 0 1 1 1 0 1 0 d d d d d d d d d d d d d d d d ..."),
+            new SPICommand("TXBUFCP 0 0 1 1 1 1 1 p c c c c c c c c 0 0 0 0 a a a a a a a a a a a a"),
+            new SPICommand("RANDOM 0 0 1 1 1 1 0 0 - - - - - - - - - - - - - - - - ..."),
+            new SPICommand("SXOSCON 0 1 0 0 0 0 0 0"),
+            new SPICommand("STXCAL 0 1 0 0 0 0 0 1"),
+            new SPICommand("SRXON 0 1 0 0 0 0 1 0"),
+            new SPICommand("STXON 0 1 0 0 0 0 1 1"),
+            new SPICommand("STXONCCA 0 1 0 0 0 1 0 0"),
+            new SPICommand("SRFOFF 0 1 0 0 0 1 0 1"),
+            new SPICommand("SXOSCOFF 0 1 0 0 0 1 1 0"),
+            new SPICommand("SFLUSHRX 0 1 0 0 0 1 1 1"),
+            new SPICommand("SFLUSHTX 0 1 0 0 1 0 0 0"),
+            new SPICommand("SACK 0 1 0 0 1 0 0 1"),
+            new SPICommand("SACKPEND 0 1 0 0 1 0 1 0"),
+            new SPICommand("SNACK 0 1 0 0 1 0 1 1"),
+            new SPICommand("SRXMASKBITSET 0 1 0 0 1 1 0 0"),
+            new SPICommand("SRXMASKBITCLR 0 1 0 0 1 1 0 1"),
+            new SPICommand("RXMASKAND 0 1 0 0 1 1 1 0 d d d d d d d d d d d d d d d d"),
+            new SPICommand("RXMASKOR 0 1 0 0 1 1 1 1 d d d d d d d d d d d d d d d d"),
+            new SPICommand("MEMCP 0 1 0 1 0 0 0 p c c c c c c c c a a a a e e e e a a a a a a a a e e e e e e e e"),
+            new SPICommand("MEMCPR 0 1 0 1 0 0 1 p c c c c c c c c a a a a e e e e a a a a a a a a e e e e e e e e"),
+            new SPICommand("MEMXCP 0 1 0 1 0 1 0 p c c c c c c c c a a a a e e e e a a a a a a a a e e e e e e e e"),
+            new SPICommand("MEMXWR 0 1 0 1 0 1 1 0 0 0 0 0 a a a a a a a a a a a a d d d d d d d d ..."),
+            new SPICommand("BCLR 0 1 0 1 1 0 0 0 a a a a a b b b"),
+            new SPICommand("BSET 0 1 0 1 1 0 0 1 a a a a a b b b"),
+            new SPICommand("CTR/UCTR 0 1 1 0 0 0 0 p k k k k k k k k 0 c c c c c c c n n n n n n n n a a a a e e e e a a a a a a a a e e e e e e e e"),
+            new SPICommand("CBCMAC 0 1 1 0 0 1 0 p k k k k k k k k 0 c c c c c c c a a a a e e e e a a a a a a a a e e e e e e e e 0 0 0 0 0 mmm"),
+            new SPICommand("UCBCMAC 0 1 1 0 0 1 1 p k k k k k k k k 0 c c c c c c c 0 0 0 0 a a a a a a a a a a a a 0 0 0 0 0 mmm"),
+            new SPICommand("CCM 0 1 1 0 1 0 0 p k k k k k k k k 0 c c c c c c c n n n n n n n n a a a a e e e e a a a a a a a a e e e e e e e e 0 f f f f f f f 0 0 0 0 0 0 mm"),
+            new SPICommand("UCCM 0 1 1 0 1 0 1 p k k k k k k k k 0 c c c c c c c n n n n n n n n a a a a e e e e a a a a a a a a e e e e e e e e 0 f f f f f f f 0 0 0 0 0 0 mm"),
+            new SPICommand("ECB 0 1 1 1 0 0 0 p k k k k k k k k c c c c a a a a a a a a a a a a 0 0 0 0 e e e e e e e e e e e e"),
+            new SPICommand("ECBO 0 1 1 1 0 0 1 p k k k k k k k k c c c c a a a a a a a a a a a a"),
+            new SPICommand("ECBX 0 1 1 1 0 1 0 p k k k k k k k k c c c c a a a a a a a a a a a a 0 0 0 0 e e e e e e e e e e e e"),
+            new SPICommand("INC 0 1 1 1 1 0 0 p 0 0 c c a a a a a a a a a a a a"),
+            new SPICommand("ABORT 0 1 1 1 1 1 1 1 0 0 0 0 0 0 c c"),
+            new SPICommand("REGRD 1 0 a a a a a a - - - - - - - - ..."),
+            new SPICommand("REGWR 1 1 a a a a a a d d d d d d d d ...")
+    };
+    
+    SPICommand[] commands = new SPICommand[256];
+    
+    CC2520SPI() {
+
+        for (int i = 0; i < spiCommands.length; i++) {
+            SPICommand c = spiCommands[i];
+            int maxv = 1 << (8 - c.bitCount);
+            int v = c.value;
+            /* populate an array with the values for quick decoding */
+            for (int j = 0; j < maxv; j++) {
+                System.out.printf(c.name + " =>  Value: %x\n", (v + j));
+                if (commands[v + j] != null) {
+                    System.out.println("ERROR: command already registered: " + commands[v + j].name);
+                }
+                commands[v + j] = c;
+            }
+        }    
+    }
+    
+    public static void main(String[] args) {
+        new CC2520SPI();
+    }
+    
+}