SPMU447 June 2026 CC2755P20
Internal Loop Back Mode is entered by programming bits TEST.LBCK and CCCR.MON to one. This mode can be used for a “Hot Selftest,” meaning the M_CAN can be tested without affecting a running CAN system connected to the pins m_can_tx and m_can_rx. In this mode pin m_can_rx is disconnected from the M_CAN and pin m_can_tx is held recessive. The figure below shows the connection of m_can_tx and m_can_rx to the M_CAN in case of Internal Loop Back Mode.