We are currently having a bit of difficulty with the Infineon micros. I think that this problem might have been around before but I might have missed it when I debugged the system months ago.
An explanation of the system… 1. I am using the XC888 microcontroller 2. I am just using a RC on the reset pin and there is no watchdog timer. 3. Both CAN node 0 and 1 are in use – the external harness is looped back. 4. I am using a TJA1040 HS CAN transceiver which is very common @125kbaud. 5. There are no FIFOs and one MO is a RX (with ISR) and one is TX (no ISR). 6. The circuit uses a 8MHz crystal for clocking.
Basically here’s what we know… 1. When I power up the system from being completely flat/discharged/0V the CAN communications do not start to work. 2. When I put a breakpoint in the program after “MAIN_vInit()” it is reached! Even in the above condition.
3. When I take the power supply lead and briefly disconnect it to cause a discontinuity in power the CAN communications begin to work 4. After this, whenever I re-flash the device, the CAN communications will always work.
5. When I power down the system fully and re power up it stops working again.
The problem… Myself (and others) are suspicious about the reset behaviour of the microcontroller. The XC micro. has several types of reset. What is the consequence if the reset line is de-asserted too early? Are we missing a piece of software that deals with one of these? Is the capacitor on the reset line too small? How is it that the software does not initialise the first time the system is powered up, but does other times?
If you could advise on these it would be muchly appreciated!!!