Diff: mmSPI.cpp

Revision:

18:4a29cad91540

Parent:

17:b81c0c1f312f

Child:

19:c2b753533b93

--- a/mmSPI.cpp	Mon Aug 19 18:26:39 2013 +0000
+++ b/mmSPI.cpp	Mon Aug 19 20:45:29 2013 +0000
@@ -144,10 +144,7 @@
       {
         dMisoByteIndex = dIndex / 8;
         dMisoBitIndex  = dIndex % 8;
-        pcReceive[dMisoByteIndex] = pcReceive[dMisoByteIndex] | (*pMISO << dMisoBitIndex);
-        
-//         pcReceive[dMisoByteIndex] = pcReceive[dMisoByteIndex] | (0x23 << dMisoBitIndex);
-      
+        pcReceive[dMisoByteIndex] = pcReceive[dMisoByteIndex] | (*pMISO << dMisoBitIndex);      
         *pSCLK = 1;             
         wait(fSPIquarterP); 
         wait(fSPIquarterP); 
@@ -252,20 +249,21 @@
 //----------------------------------------------//------------------------------
     void mmSPI::write_register(char cRegister, char cValue, char * pcReceive, char * pcSend)
     {     
-      pcSend[7] = 0x02;
+      int dLoop;                                // loop index.
+      
+                                                // clear transmit vector.
+      for (dLoop = 0; dLoop < 8; dLoop++) pcSend[dLoop] = 0x00; 
+      
+      pcSend[7] = 0x02;                         // mbed sends a command.
+      
+                                                // align into instruction word.
       pcSend[1] = ((cRegister & 0x07) << 2) | 0xA0;
-      pcSend[0] = cValue & 0xFF;
- 
-      transceive_vector2(pcReceive, pcSend, 8);
+      pcSend[0] = cValue & 0xFF;                // immediate value to i.w.
  
-      pcSend[7] = 0x00;
-      pcSend[6] = 0x00;
-      pcSend[5] = 0x00;
-      pcSend[4] = 0x00;
-      pcSend[3] = 0x00;
-      pcSend[2] = 0x00;
-      pcSend[1] = 0x00;
-      pcSend[0] = 0x00;
+      transceive_vector2(pcReceive, pcSend, 8); // transmit command.
+ 
+                                                // clear transmit vector.
+      for (dLoop = 0; dLoop < 8; dLoop++) pcSend[dLoop] = 0x00; 
     }
 //----------------------------------------------//------------------------------
                                                 // returns the content of
@@ -273,14 +271,80 @@
     char mmSPI::read_register(char cRegister, char * pcReceive, char * pcSend)
     { 
       int dLoop;                                // send all 0.
-      for (dLoop = 0; dLoop < 8; dLoop++) pcSend = 0x00;    
-      
-                                                
+      for (dLoop = 0; dLoop < 8; dLoop++) pcSend[dLoop] = 0x00;    
+                   
       transceive_vector2(pcReceive, pcSend, 8); // snap & scan-out reg contents.
       
       return (pcReceive[cRegister]);            // return the particular reg value.
     }
 //----------------------------------------------//------------------------------
+    void mmSPI::write_memory(char cHData, char cLdata, char cAddress, char * pcReceive, char * pcSend)
+    {
+      int dLoop;                                // loop index.
+    
+                                                // clear transmit vector.
+      for (dLoop = 0; dLoop < 8; dLoop++) pcSend[dLoop] = 0x00;   
+ 
+                                                // R3 <- address.
+                                                // R2 <- high-data.
+                                                // R1 <- low-data.
+      write_register(0x03,cAddress, pcReceive, pcSend); 
+      write_register(0x02,cHData,   pcReceive, pcSend);
+      write_register(0x01,cLdata,   pcReceive, pcSend);
+  
+      pcSend[7] = 0x02;                         // write-enable high.
+      pcSend[1] = 0x02;
+      pcSend[0] = 0x00;
+         
+      
+      transceive_vector2(pcReceive, pcSend, 8);
+      
+      pcSend[7] = 0x02;                         // write-enable low.
+      pcSend[1] = 0x00;
+      pcSend[0] = 0x00;
+      transceive_vector2(pcReceive, pcSend, 8);   
+      
+                                                // clear transmit vector.
+      for (dLoop = 0; dLoop < 8; dLoop++) pcSend[dLoop] = 0x00; 
+    }
+//----------------------------------------------//------------------------------
+                                                // fetch a word from main memory.
+    unsigned int mmSPI::read_memory(char cAddress, char * pcReceive, char * pcSend)
+    {
+      int          dLoop;                       // loop index.   
+      unsigned int udMemoryContent;             // return variable.
+      char         cHData;                      // returned data-high.
+      char         cLData;                      // returned data-low.
+    
+                                                // clear transmit vector.
+      for (dLoop = 0; dLoop < 8; dLoop++) pcSend[dLoop] = 0x00;  
+      
+                                                // R3 <- address.
+      write_register(0x03,cAddress, pcReceive, pcSend);
+      
+      pcSend[7] = 0x02;                         // mbed sends command.
+      pcSend[1] = 0x68;                         // R2 <- MM[R3]
+      pcSend[0] = 0x00;
+      transceive_vector2(pcReceive, pcSend, 8); // send command. 
+      
+      pcSend[7] = 0x02;                         // mbed sends command.
+      pcSend[1] = 0x64;                         // R1 <- MM[R3]
+      pcSend[0] = 0x00;
+      transceive_vector2(pcReceive, pcSend, 8); // send command.      
+           
+                                                // obtain MM content.
+      cHData = read_register(0x02, pcReceive, pcSend);  
+      cLData = read_register(0x01, pcReceive, pcSend);    
+    
+                                                
+      udMemoryContent = (cHData << 8) + cLData; // build the memory word.
+      
+                                                // clear transmit vector.
+      for (dLoop = 0; dLoop < 8; dLoop++) pcSend[dLoop] = 0x00;
+    
+      return udMemoryContent;                   // return the memory word.
+    }
+//----------------------------------------------//------------------------------
 
 
     void mmSPI::write_pulse(char * pcReceive, char * pcSend)