Change/add methods

1. Change receiveMsg. Now it returns int16 with error identification
2. Change CANMessage structure. Now it only has dataLenght variable
   instead of previos MsgCtrlReg union
3. Change MsgCtrlReg. Add an OPC flag in it
4. Change configRxMBox method. Overwrite protection enabling is
   added

Protocol/CAN.cpp

@@ -14,7 +14,7 @@ void CAN::transmitMsg(Uint16 boxNumber, const CANMessage& message){
     p_MailBox->MDH.all = 0x0;
     p_MailBox->MDL.all = 0x0;
 
-    p_MailBox->MSGCTRL.bit.DLC = message.msgctrl.bit.DLC;
+    p_MailBox->MSGCTRL.bit.DLC = message.dataLength;
     p_MailBox->MDH.all = message.mdh.all;
     p_MailBox->MDL.all = message.mdl.all;
 
@@ -109,6 +109,7 @@ void CAN::updateTXMessage(Uint16 boxNumber, const CANMessage& message){ // TODO
     // Set change data request (CDR bit + MBOX number)
     p_CanRegs_->CANMC.all |= (128 + boxNumber);
 
+    // TODO Add lenght changing?
     p_MailBox->MDL.all = message.mdl.all;
     p_MailBox->MDH.all = message.mdh.all;
 
@@ -146,7 +147,7 @@ void CAN::sendRemoteRequest(Uint16 boxNumber){
 }
 
 
-bool CAN::receiveMsg(Uint16 boxNumber, CANMessage& rxMessage){ // TODO faults just return -1
+int16 CAN::receiveMsg(Uint16 boxNumber, CANMessage& rxMessage){ // TODO faults just return -1
     if (boxNumber > 31) { return -1; }
 
     Uint32 mboxControl(0);
@@ -156,11 +157,11 @@ bool CAN::receiveMsg(Uint16 boxNumber, CANMessage& rxMessage){ // TODO faults ju
     p_MailBox = &(p_CanMBoxes_->MBOX0) + boxNumber;
 
     bool isNewMessageInBox = p_CanRegs_->CANRMP.all & mboxControl;
-    if(!isNewMessageInBox) return -1;
+    if(!isNewMessageInBox) return -2;
 
     p_CanRegs_->CANRMP.all &= mboxControl;
 
-    rxMessage.msgctrl.all = p_MailBox->MSGCTRL.all;
+    rxMessage.dataLength = p_MailBox->MSGCTRL.all;
     rxMessage.mdl.all = p_MailBox->MDL.all;
     rxMessage.mdh.all = p_MailBox->MDH.all;
 
@@ -171,7 +172,7 @@ bool CAN::receiveMsg(Uint16 boxNumber, CANMessage& rxMessage){ // TODO faults ju
     lostMessage = p_CanRegs_->CANRML.all & mboxControl;
 
     if(newMessage || lostMessage) {
-        return -1;
+        return -3;
     }
 
     return 0;

Protocol/CAN.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include "DSP2833x_Device.h"
 #include "DSP28x_Project.h"
 
 namespace canSpace {
@@ -36,7 +37,8 @@ enum configSystemIsrFlags{
 struct MsgCtrlBits {     // bits  description
     Uint16      DLC:4;             // 0:3
     Uint16      RTR:1;             // 4
-    Uint16      rsvd1:3;           // 7:5   reserved
+    Uint16      OPC:1;             // 1
+    Uint16      rsvd1:2;           // 7:6   reserved
     Uint16      TPL:5;             // 12:8
     Uint16      rsvd2:3;           // 15:13 reserved
 };
@@ -86,7 +88,7 @@ union MsgID {
 
 
 struct CANMessage {
-    union MsgCtrlReg msgctrl;
+    Uint16 dataLength;
     union CANMDL_REG mdl;
     union CANMDH_REG mdh;
 
@@ -116,7 +118,7 @@ public:
     void transmitMsg(Uint16 boxNumber, const Uint32& message, const Uint16 dlc);
     void updateTXMessage(Uint16 boxNumber, const CANMessage& message);
     void sendRemoteRequest(Uint16 boxNumber);
-    bool receiveMsg(Uint16 boxNumber, CANMessage& rxMessage);
+    int16 receiveMsg(Uint16 boxNumber, CANMessage& rxMessage);
 
 private:
     CAN_VARIANT canPort;

Protocol/CANConfig.cpp

@@ -252,9 +252,11 @@ void CAN::configRxMBox(Uint16 boxNumber, const MsgID& configID, const MsgCtrlReg
 
     // Overwrite protection
     // If "ON" make sure that an additional mailbox is configured to store ’overflow’ messages.
-    // CanShadow_.CANOPC.all = p_CanRegs_->CANOPC.all;
-    // CanShadow_.CANOPC.all |= mboxControl;                // Should be one more mailbox to store 'overflow' messages
-    // p_CanRegs_->CANOPC.all = CanShadow_.CANOPC.all;
+    if(configCtrlReg.bit.OPC){
+        CanShadow_.CANOPC.all = p_CanRegs_->CANOPC.all;
+        CanShadow_.CANOPC.all |= mboxControl;
+        p_CanRegs_->CANOPC.all = CanShadow_.CANOPC.all;
+    }
 
     // Enable Mailbox
     CanShadow_.CANME.all = p_CanRegs_->CANME.all;

main.cpp

@@ -88,7 +88,7 @@ void main()
 
     CpuTimer0.RegsAddr->TCR.bit.TSS = 0;
 
-    message.msgctrl.bit.DLC = 8;
+    message.dataLength = 8;
     message.mdl.byte.BYTE0 = 0x11;
     message.mdl.byte.BYTE1 = 0x22;
     message.mdl.byte.BYTE2 = 0x33;
@@ -157,9 +157,12 @@ interrupt void canb_isr(void){
     canISRcounter++;
 
     CANGIF0_REG CANGIF0_SHADOW;
+    volatile Uint32 resetBit;
+
     CANGIF0_SHADOW.all = ECanbRegs.CANGIF0.all;
 
     if (CANGIF0_SHADOW.bit.WLIF0){
+        resetBit = 256;
         ECanbRegs.CANGIF0.all = 256ul;
     }