SAM3X8E Atmel Corporation, SAM3X8E Datasheet - Page 1221

• Manufacturer Part Number: SAM3X8E
• Manufacturer: Atmel Corporation

Figure 40-9. Disabling Low-power Mode
40.8
40.8.1
11057A–ATARM–17-Feb-12
11057A–ATARM–17-Feb-12
Functional Description
(CAN_MSRx)
CAN Controller Initialization
(CAN_SR)
WAKEUP
(CAN_MR)
(CAN_SR)
CAN BUS
SLEEP
MRDY
LPM
After power-up reset, the CAN controller is disabled. The CAN controller clock must be activated
by the Power Management Controller (PMC) and the CAN controller interrupt line must be
enabled by the interrupt controller (AIC).
The CAN controller must be initialized with the CAN network parameters. The CAN_BR register
defines the sampling point in the bit time period. CAN_BR must be set before the CAN controller
is enabled by setting the CANEN field in the CAN_MR register.
The CAN controller is enabled by setting the CANEN flag in the CAN_MR register. At this stage,
the internal CAN controller state machine is reset, error counters are reset to 0, error flags are
reset to 0.
Once the CAN controller is enabled, bus synchronization is done automatically by scanning
eleven recessive bits. The WAKEUP bit in the CAN_SR register is automatically set to 1 when
the CAN controller is synchronized (WAKEUP and SLEEP are stuck at 0 after a reset).
The CAN controller can start listening to the network in Autobaud Mode. In this case, the error
counters are locked and a mailbox may be configured in Receive Mode. By scanning error flags,
the CAN_BR register values synchronized with the network. Once no error has been detected,
the application disables the Autobaud Mode, clearing the ABM field in the CAN_MR register.
Message lost
Interframe synchronization
Bus Activity Detected
Message x
SAM3X/A
SAM3X/A
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