SWRU626 December 2025 CC3501E , CC3551E
The DCAN can be set into power down mode controlled by input signal m_can_clkstop_req or via CC Control Register CCCR.CSR. As long as the clock stop request signal d_can_clkstop_req is active, bit CCCR.CSR is read as one.
When all pending transmission requests have completed, the DCAN waits until bus idle state is detected. Then the DCAN sets then CCCR.INIT to one to prevent any further CAN transfers. Now the DCAN acknowledges that it is ready for power down by setting output signal d_can_clkstop_ack to one and CCCR.CSA to one. In this state, before the clocks are switched off, further register accesses can be made. A write access to CCCR.INIT will have no effect. Now the module clock inputs d_can_hclk and d_can_cclk may be switched off.
To leave power down mode, the application has to turn on the module clocks before resetting signal d_can_clkstop_req resp. CC Control Register flag CCCR.CSR. The DCAN will acknowledge this by resetting output signal d_can_clkstop_ack and resetting CCCR.CSA. Afterwards, the application can restart CAN communication by resetting bit CCCR.INIT.