The technical reference manual for the Hercules RM44 chip says that the TX pin can be used to monitor the sampling point (Table 24-12, Test Register Field Descriptions).
But I cannot get this to work, the TX pin is permanently a logical 0.
What I did
Init():
- Go into init mode.
- Set test bit in control register to '1'.
- Set bits 6-5 to '0b01' in test register.
- Set up baud rate, etc.
- Leave init mode.
Result:
DCAN2 control register == 0x00031483
DCAN test register == 000000A0
The controller is connected to a CAN bus where a packet generator sends a message every 500 ms.
What happens:
The RX pin correctly receives the message, but the TX pin is permanently low/zero.
What I expected:
I thought the TX pin would now change on the sampling point of each received bit or something.
Is that how it is supposed to work? Am I doing it right?
