One of the most important aspects of the TCAN284XX/TCAN285XX line of SBCs is the ability to act as a communication node for multiple different standards depending on direct device variant. The families of devices can be thought of as CAN SBCs with options for CAN-SIC and LIN. The TCAN284XEVM is set up for all device variants and can support testing with all communication modes.

All devices in the TCAN284XX family are CAN and CAN-FD capable. The main configuration registers associated with the CAN bus are Ch (SBC configuration), 10h (CAN Control), and 44h (CAN/CAN-FD data rate). The CAN transceiver cannot be on in any other mode than normal mode. The suggestion is to either force the CAN transceiver to follow SBC mode in register 10h or switch the SBC to normal mode before turning on the CAN transceiver.

Figure 2-3 CAN Termination Styles Available on Board

The CAN bus on the TCAN284XEVM contains a common mode choke, pads for protection diodes and filtering caps, a CAN monitor, and three different termination styles. A standard resistive load, a split termination, and a SIC termination (only used on TCAN285XX devices). The split termination is employed to help mitigate issues from emissions by creating a low pass filter. To enable a standard termination on the CAN bus, J26 and J32 are shunted. For a split termination setup J27 and J33 are shunted instead. The CANL and CANH lines can be router externally through the CAN monitor header pins located at J28 or the CANH and CANL lines can be brought off-board through the DSUB-9 connector at J29. Single ended data for CAN is based on the CTXD and CRXD signals and are referenced to the ICs VCC1 level. The CTXD (transmit) and CRXD (receive) pins can be accessed through header block J30. While basic testing of the CAN bus can occur with a simple signal generator on these pins, for full scale CAN testing an external CAN controller must control the CTXD and CRXD pins.

For devices in the TCAN285XX family, most of the information remains the same as above. Except that the TCAN285XX family is CAN-SIC, which means that the recessive edge is driven unlike standard CAN. This can help mitigate issues due to ringing on the differential bus. The main difference when using the TCAN285XX family is that the termination style on the board is specific to SIC testing, so while the standard and split options are still available a specific SIC load can be applied by shunting J25 and J31.

In addition to CAN device, variants with the product number pattern of TCAN2847X/TCAN2857X are also LIN capable and the TCAN284XEVM allows for easy LIN usage in both responder and commander applications. The LIN transceiver can be configured at address 1Dh, similar to the CAN functionality the SBC must be in normal mode for the LIN bus to operate normally. LIN can be tied to SBC mode control similar to CAN functionality. The LIN bus contains a 220pF filter capacitor and a protection diode. The LIN bus can be access at the LIN monitor at J20, the external LIN header at J21, or through the DSUB-9 connector at J24. If the LIN node is a commander header J14 needs to be shunted to pull-up the node to battery supply voltage. Indicator LED D10 lights up when LIN bus drives low. The single ended pins are LTXD and LRXD and are referenced to devices VCC1 voltage level. These pins can be accessed through header block J30.