SWRU626 December 2025 CC3501E , CC3551E
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 DCAN can be tested without affecting a running CAN system connected to the pins DCAN_TX and DCAN_RX. In this mode pin DCAN_RX is disconnected from the DCAN and pin DCAN_TX is held recessive. Figure 13-12 shows the connection of DCAN_TX and DCAN_RX to the DCAN in case of Internal Loop Back Mode.