topic Re: CodeWarrior and Trim Value Calculation for the MC68HC908KX8 in CodeWarrior for MCU

CodeWarrior and Trim Value Calculation for the MC68HC908KX8

bespenschied — Mon, 01 May 2006 12:56:19 GMT

Is there a method of calculating the Trim Value for the 908KX8 cpu internal clock in CodeWarrior or the true-time simulator/debugger? I have been using an external Oscillator and am now ready to try the internal timer. I keep seing references in these forums for this calculation using the P&E tools but I have not been able to find any specifics. I am using a simple MON08 interface I built to interface my target to CodeWarrior.

bcde

Re: CodeWarrior and Trim Value Calculation for the MC68HC908KX8

peg — Mon, 01 May 2006 15:12:39 GMT

Hi Brian,

AFAIK there is no direct support for auto clock trimming in CW (hiwave) even though there is an option to do the trim under advanced options.

It seems to depend entirely on your interface.

If you are using a P&E USB multilink or cyclone etc it will get the P&E part of the software to do the trim for you.

So to summarise AFAIK the only time you get auto cal in CW is with S08's using P&E BDM interface. (Maybe Softec as well???).

If anyone knows something different please pipe in as I would like to know as well.

So you are stuck with manual calibration and then being annoyed by CW's insistance on erasing before flashing and zapping your NV trim.

BR Peg

Re: CodeWarrior and Trim Value Calculation for the MC68HC908KX8

bespenschied — Thu, 04 May 2006 10:21:57 GMT

Thanks peg!

I only have an interface I made so I guess I will get busy on learning how to do it manually. It is worth it if I can save the cost of a digital oscillator or crystal.

bcde

Re: CodeWarrior and Trim Value Calculation for the MC68HC908KX8

peg — Thu, 04 May 2006 10:35:28 GMT

Hi Brian,

Take a look at AN2498, AN2312 and AN2496.

Regards Peg