TJA1145T/FD

[carlos_kan]

Hi, noob here.

About TJA1145T/FD,I have a question:

I have refer to several designs with TJA1145T and I found that the 1145 communicates with microcontroller through SPI.If I follow the hardware design of 1145 but not send any SPI frame to 1145 when I power on the MCU board(In SW not initial the 1145),is the 1145 in operating mode or can MCU transmit and receive CAN frames by 1145?

I have code of a S32K application which uses UJA1169. However,there is no code about UJA1169 initial and SPI communication with microcontroller ,but it can still transfer CAN data.

You reply will be highly appreciated.Thanks.

[PetrS · Accepted solution]

Hi, 

upon power on TJA1145 enters Standby mode with CAN transceiver disabled, you need to send command over SPI. That is put TJA1145 in Normal mode (MC = 111) and enable CAN transceiver by setting bits CMC in the CAN control register to 01 or 10.

BR, Petr