518
CHAPTER 23 CAN CONTROLLER
23.15
Setting the CAN Direct Mode Register
The MB90390 series provides a clock modulator for the system clock. Since the CAN
controller is not able to operate with a modulated clock, the unmodulated clock is
provided to the CAN controller independently from the clock modulator settings.
■
CAN Direct Mode Register (CDMR)
Figure 23.15-1 Configuration of the CAN Direct Mode Register (CDMR)
■
CAN Direct Mode Register Contents
Initial value
X X X X X X X 0
B
Address:
H
CAN0: 00356E
CDMR
-
-
-
-
R/W
- - - -
-
-
-
DIRECT
- - -
7
bit
6
5
4
3
2
1
0
X
:
Undefined value
-
:
Undefined
R/W
:
Readable and
w
ritable
Table 23.15-1 Function of the DIRECT Bit of the CAN Direct Mode Register
Bit name
Function
bit7 to bit1
Undefined
−
bit0
DIRECT
The value "1" should be written to this bit when the clock modulation is disabled.
Then, the CAN Controller skips synchronization to the modulated clock, making
the communication between CAN and CPU as fast as possible.
The value "0" must be written to this bit if the clock modulation is enabled in order
to synchronize modulated system clock and unmodulated CAN clock.
Summary of Contents for MB90390 Series
Page 2: ......
Page 4: ......
Page 17: ...xiii APPENDIX D List of Interrupt Vectors 690 INDEX 695 ...
Page 18: ...xiv ...
Page 132: ...104 CHAPTER 5 CLOCKS ...
Page 152: ...124 CHAPTER 6 CLOCK MODULATOR ...
Page 210: ...182 CHAPTER 11 TIME BASE TIMER ...
Page 218: ...190 CHAPTER 12 WATCHDOG TIMER ...
Page 264: ...236 CHAPTER 14 16 BIT RELOAD TIMER WITH EVENT COUNT FUNCTION ...
Page 274: ...246 CHAPTER 15 WATCH TIMER ...
Page 306: ...278 CHAPTER 17 DTP EXTERNAL INTERRUPTS ...
Page 338: ...310 CHAPTER 18 8 10 BIT A D CONVERTER ...
Page 364: ...336 CHAPTER 19 UART0 UART1 ...
Page 398: ...370 CHAPTER 20 UART2 UART3 Figure 20 5 2 ORE Set Timing Receive data RDRF ORE ...
Page 432: ...404 CHAPTER 20 UART2 UART3 ...
Page 482: ...454 CHAPTER 22 SERIAL I O ...
Page 560: ...532 CHAPTER 24 STEPPING MOTOR CONTROLLER ...
Page 582: ...554 CHAPTER 27 ROM MIRRORING MODULE ...
Page 632: ...604 CHAPTER 29 EXAMPLES OF SERIAL PROGRAMMING CONNECTION ...
Page 722: ...694 APPENDIX ...
Page 723: ...695 INDEX The index follows on the next page This is listed in alphabetic order ...
Page 740: ......