ZHCSJK5C January 2018 – October 2020 TCAN4550-Q1
This pin defaults out as the M_CAN_INT 1 (active low) interrupt. The functionality of the pin can be changed to a configurable output function pin by setting register 16'h0800[15:14] = 00. The GPO function is further configured by using register 16'h0800[11:10]. To configure the pin to support a watchdog input timer reset pin use SPI register 16'h0800[15:14] = 10.
When in test mode the GPIO1 pin is used to provide the input signal for the transceiver (TXD_INT_PHY) or the input to the M_CAN core (RXD_INT_CAN). This is accomplished by first putting the device into test mode using register 16'h0800 = 1 and then selecting which part of the device is to be tested by setting register 16'h0800