TMS320F2812: EMU1 pin causes CPU to get into lock up mode.

Hi Mike,

Michael Stach said:

The (PWM) peripheral is still operating with its last updated value when it is in the "lockup" state.

When you have the device in this state, are you still able to read the device registers? 

This is such an old device, it is difficult to find documentation, so I am not yet sure whether there is a register that would show this.

Best Regards,

Ben Collier

When JTAG is connected we are not getting it into this mode. So, no chance to read any registers. We toggle a GPIO in the illegal isr service routine, we can see it sometimes toggle the GPIO (means it is an illegal isr), sometimes it does not (we are not sure what mode it is in then).

When JTAG is connected we are not getting it into this mode. So, no chance to read any registers. We toggle a GPIO in the illegal isr service routine, we can see it sometimes toggle the GPIO (means it is an illegal isr), sometimes it does not (we are not sure what mode it is in then).

Can you take an oscilloscope capture of the TRST signal during operation? Is it really noisy? 

I had scoped TRST before, no noise, didn't take a picture though. I even had tied the TRST pin to GND, and still the same thing happens, when touching the EMU1 pin to GND thru a resistor the chip locks up. Sometimes it is an illegal isr, but not always. 

Michael,

If there is no noise on your TRST pin, then you are not going into boundary scan mode since TRST is pulled low.

What is your application with F2812? Do you see this same behavior when running a simple example? 

Best Regards,

Ben Collier