DEMO9S08SV16 - Debugger interfers with SCI port

[JJHawg]

Greetings.

I have just received a DEMO9S08SV16 board, and ported some code written for another chip

sucessfully. Nice job with CodeWarrior and PE!

However, when I try to use the RS-232 port with the debugger running, the data is garbled.

When I close the debugger and reset the chip, all is well. I can tolerate this for now, but it would

be nice to get this resolved.

Has anyone else had this problem, or seen  referrence to a solution?

Thanks,

Jim

[peg]

Hello Jim,

The so called non-intrusive debugger actually steals cycles from the application. How precise is your baudrate? If it is not spot on are you high or low? If you are on the low side, try the high side this may allow it to slow a little and still remain tolerable.

[JJHawg]

Thanks for the quick relay, Peg.

That's actually another problem, I was unable to select clock freqs that got very close to 19200 baud, and it is about 1.2% high, I think. However, I ran 4800, which gave around .2% error, and got the same italic i instead of capital A, in a test program. I have not yet looked at the bit pattern difference between these characters, or put a scope on the line yet.

When I tried to run my application at slow baud rates, I had other timing problems in the code, so I gave up trying to fix it at that time.

Thanks for the lead, though, I will perform some measurment on the data line and see what I am dealing with. If that is the only problem, I can live with it during debug sessions, and just kill the debugger otherwise...

Thanks,

Jim