552
CHAPTER 16 CAN controller
16.6
Precautions when Using CAN Controller
Use of the CAN Controller requires the following cautions.
■
Caution for disabling message buffers by BVAL bits
The use of BVAL bits may affect malfunction of CAN Controller when messages buffers are set disabled
while CAN Controller is participating in CAN communication (the read value of the CSR: HALT bit is 0
and CAN Controller is ready to transmit messages). This section shows the work around of this
malfunction.
●
Condition
When following two conditions occur at the same time, the CAN Controller will not perform to transmit
messages normally.
•
CAN Controller is participating in the CAN communication. (i.e. The read value of the CSR: HALT bit
is 0 and CAN Controller is ready to transmit messages)
•
Message buffers are read when BVAL bits disable the message buffers.
●
Work around
Operation for suppressing transmission request
Do not use BVAL bit for suppressing transmission request, use TCAN bit instead of it.
Operation for composing transmission message
For composing a transmission message, it is necessary to disable the message buffer by BVAL bit to
change contents of ID and IDE registers. In this case, BVAL bit should reset (BVAL=0) after checking
if TREQ bit is 0 or after completion of the previous message transmission (TC=1).
In case a buffer needs to be disabled, ensure that no transmission request is pending (if it was requested
before)! Therefore, do not reset BVALx-Bit before testing, if a transmission is ongoing:
a) Cancel the transmission request (TCANx=1;), if necessary
b) Wait for the transmission completion (while (TREQx==1);) by polling or interrupt.
Only after that the transmission buffer can be disabled (BVALx=0;).
Note:
Note for case a), if transmission of that buffer has already started, canceling the request is ignored and
disabling the buffer is delayed until the end of the transmission.
Summary of Contents for F2MC-16LX Series
Page 2: ......
Page 3: ...FUJITSU LIMITED F2MC 16LX 16 bit Microcontroller MB90895 series Hardware Manual ...
Page 4: ......
Page 8: ...iv ...
Page 10: ...vi ...
Page 36: ...18 CHAPTER 2 HANDLING DEVICES ...
Page 176: ...158 CHAPTER 3 CPU ...
Page 224: ...206 CHAPTER 5 Timebase timer ...
Page 294: ...276 CHAPTER 8 16 bit reload timer ...
Page 366: ...348 CHAPTER 12 DTP external interrupt ...
Page 398: ...380 CHAPTER 13 8 10 bit A D converter ...
Page 446: ...428 CHAPTER 14 UART0 ...
Page 588: ...570 CHAPTER 17 Address Match Detecting Function ...
Page 626: ...608 CHAPTER 19 512 KBIT FLASH MEMORY ...
Page 676: ...658 APPENDIX Table A 9 3 Bit Operation Instruction Map first byte 6CH ...
Page 678: ...660 APPENDIX Table A 9 5 2 byte Instruction Map first byte 6FH MUL MULW DIVU A A A ...
Page 680: ...662 APPENDIX Table A 9 7 ea Instruction 2 first byte 71H ...
Page 681: ...663 APPENDIX A Instructions Table A 9 8 ea Instruction 3 first byte 72H ...
Page 682: ...664 APPENDIX Table A 9 9 ea Instruction 4 first byte 73H ...
Page 683: ...665 APPENDIX A Instructions Table A 9 10 ea Instruction 5 first byte 74H ...
Page 684: ...666 APPENDIX Table A 9 11 ea Instruction 6 first byte 75H ...
Page 685: ...667 APPENDIX A Instructions Table A 9 12 ea Instruction 7 first byte 76H ...
Page 686: ...668 APPENDIX Table A 9 13 ea Instruction 8 first byte 77H ...
Page 687: ...669 APPENDIX A Instructions Table A 9 14 ea Instruction 9 first byte 78H ...
Page 688: ...670 APPENDIX Table A 9 15 MOVEA RWi ea Instruction first byte 79H ...
Page 689: ...671 APPENDIX A Instructions Table A 9 16 MOV Ri ea Instruction first byte 7AH ...
Page 690: ...672 APPENDIX Table A 9 17 MOVW RWi ea Instruction first byte 7BH ...
Page 691: ...673 APPENDIX A Instructions Table A 9 18 MOV ea Ri Instruction first byte 7CH ...
Page 692: ...674 APPENDIX Table A 9 19 MOVW ea Rwi Instruction first byte 7DH ...
Page 693: ...675 APPENDIX A Instructions Table A 9 20 XCH Ri ea Instruction first byte 7EH ...
Page 694: ...676 APPENDIX Table A 9 21 XCHW RWi ea Instruction first byte 7FH ...
Page 710: ......