FAQs
English (US) 日本語 | Japanese 中文 | Chinese (Simplified)

Does not interface with perepheral when self powered

cancel
Turn on suggestions
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
Showing results for 
Show  only  | Search instead for 
Did you mean: 

Does not interface with perepheral when self powered

‎10-12-2006 11:01 PM
2,423 Views
pIx
Contributor I
HI

I am using S12DP512 and Codewarrior 4.5 and have this very wierd problem. When I have the P&E BDM connected and I execute the program, everything works fine. But once the code is downloaded and I power the microcontroller board by itself, it fails to programm the DAC.

I have a few other perifpherals like two UART ports connected to RS485 chips, a 16 bit ADC etc.. All of them work, except the DAC!

What could the problem likely be? I have broken my head on it and can't think of any more things to try.

Thanks,
Sujith
Labels (1)
Labels
0 Kudos
Reply
3 Replies

‎10-16-2006 06:47 AM
672 Views
DanielM
Contributor III
Hi,

The problem might boil down to a different mode of the micro: When debugging it defaults to special single chip mode, when standalone it runs in normal single chip mode.

Try changing the mode to normal single chip mode at the beginning of your code. This will ensure that the mode is always normal single chip irrespective of whether the debugger is attached or not. Then you might be able to see the problem in the debugger.

Daniel
0 Kudos
Reply

‎10-13-2006 03:47 PM
672 Views
J2MEJediMaster
Specialist I
Working with what information you've provided, I wonder if the board isn't supplying enough power to drive the DAC? You could test this theory by disabling and powering down some of the other peripherals and see if the DAC starts working.

Also, when you switch to the self-powered setup, do you change the jumpers to place the board in stand-alone mode?

---Tom
0 Kudos
Reply

‎10-13-2006 04:03 PM
672 Views
pIx
Contributor I
Thank you very much for the reply, I am in kinda of a fix. I will try out the power thing and let you know. This is a board I have made and there is no special jumper settings I have given that needs to be changed or I am wrong here:

Mode A & Mode B jumpers are set to show ground to initialize the microcontroller to single chip mode. Mode C jumper doubles as the BDM link and I am wondering if once I remove the BDM link to make it stand alone, do I need to short any of the pins on it?

Right now, I am doing nothing except just removing the BDM connector and powering the unit up and everything except the DAC is working.
0 Kudos
Reply