
Rev.2.10 Apr 14, 2006 page 234 of 378
REJ09B0124-0210
M16C/6N Group (M16C/6NK, M16C/6NM) 19. CAN Module
19.5 Operational Modes
The CAN module has the following four operational modes.
• CAN reset/Initialization mode
• CAN operation mode
• CAN sleep mode
• CAN interface sleep mode
Figure 19.12 shows the Transition between Operational Modes.
Figure 19.12 Transition between Operational Modes
19.5.1 CAN Reset/Initialization Mode
CAN reset/initialization mode is activated upon MCU reset or by setting the Reset bit in the CiCTLR
register ( i = 0, 1) to 1. If the Reset bit is set to 1, check that the State_Reset bit in the CiSTR register is set
to 1.
Entering CAN reset/initialization mode initiates the following functions by the module:
• CAN communication is impossible.
• When CAN reset/initialization mode is activated during an ongoing transmission in operation mode,
the module suspends the mode transition until completion of the transmission (successful, arbitration
loss, or error detection). Then, the State_Reset bit is set to 1, and CAN reset/initialization mode is
activated.
• Registers CiMCTLj (j = 0 to 15), CiSTR, CiICR, CiIDR, CiRECR, CiTECR, and CiTSR are initialized.
All these registers are locked to prevent CPU modification.
• Registers CiCTLR, CiCONR, CiGMR, CiLMAR, and CiLMBR, and the CANi message box retain their
contents and are available for CPU access.
MCU Reset
CAN reset/initialization
mode
State_Reset = 1
CAN operation mode
State_Reset = 0
CAN sleep mode
CAN interface
sleep mode
Bus off state
State_BusOff = 1
Reset = 0
Sleep = 1Sleep = 0
TEC > 255
Reset = 1
Reset = 1
CCLK3, CCLK7: Bits in CCLKR register
Reset, Sleep, RetBusOff: Bits in CiCTLR register ( i = 0, 1)
State_Reset, State_BusOff: Bits in CiSTR register
CCLK3 = 1 or
CCLK7 = 1
CCLK3 = 0 or
CCLK7 = 0
when 11 consecutive
recessive bits are
detected 128 times
or
RetBusOff = 1
Kommentare zu diesen Handbüchern