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MC9S12NE64 development board and TBDML?

Question asked by Ruth Hendrix Employee on Jan 26, 2006
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Posted: Wed May 11, 2005 3:01 pm    
I have a few questions on using TBDML and the MC9S12NE64 dev board...or DEMO9S12NE64 as it says on the device...

Somewhere on the TBDMLs documentation it says that it has worked with 19.5MHz on the target board....BUT the NE64 Dev board has 25MHz...should it work? ....and what happens if I change it from 25MHz to something less than 19.5MHz? The Ethernet interface stops working but the processor it self works ok....or what?

Is this the price you have to pay for using the free TBDML? debug it with one (low) clock speed then switch to the normal high clock speed... =)

This little project of mine is just for myself so changing the clock is annoying but ok...if it works! My own board is still under some work at the moment.

Posted: Wed May 11, 2005 3:34 pm    
Yes you are right, it is an issue, we toiled with the decision of which micro to use to the project, the JB8 which is handy in a DIP package or go for a faster micro and be stuck with QFP. Clearly in the end we went for the slow dip option knowing it would be an issue for the NE64. However we thought that as you have that there would be ways round it, try to do as much debugging at low speed and then crank up for testing. I don't know how well it will work, I think you are the guinea pig.
Posted: Wed May 11, 2005 4:31 pm    

I think it is time to do a Port to the JB16. SOIC is not hat hard to solder and you can double the busfrequency. This should then work up to 40 MHz, which is fast enough for HCS12 and HCS08. I´ll try to get it running when I have some time left for it. Maybe Softec is faster with their BDM reference design but nobody knows how long it will take.
Posted: Sun May 15, 2005 12:28 am    
The first job is to get the S08 port working then next to port to JB16, the problem is getting time.
Posted: Mon May 16, 2005 6:25 am    
The first job is to get the S08 port working then next to port to JB16, the problem is getting time.

I don't have a plenty time, but in my job is possible to make transfer to JB16. Today we have our own TBML in SMD.

p.s. sorry for my english, but its monday Shocked
Posted: Mon May 16, 2005 3:33 pm    

it is not all about SW. Actually, I believe that if you use the SW "as is" without any changes it should work on JB16. What will happen is that the lowest possible frequency will shift from 1MHz to 2MHz, but more interestingly the highest possible frequency will move from at least 16MHz to at least 32MHz.

The important change you need to make is in the HW. JB08 is a 3.3V part. Simple HC125 based level shifter therefore works for target voltages above 3.3V. JB16 is 5V part and the HC125 shifter would therefore only work above 5V which means no voltage shifting at all... What you need here is another part which will withstand overvoltage on its pins. Luckily On-semi do VHC125 which is just what is needed - free samples available as well. I did not use it for the JB8 design as it does not come in a DIL package, but as JB16 is in SMD already nobody will mind another SMD chip on the board.

I had a schematic for the JB16 almost ready, but later we abandoned the idea and went for "all through-hole" solution with JB8 instead to make life easier for guys will less SMD experience.

Send me a message if you want a copy of the JB16 schematic.

Posted: Tue Jun 21, 2005 9:22 pm  

I made the software port to the JB16 with a mate. It seems to work, just not perfect. i used a 74ls125 for now and it works. The software needs quite a few changes. but i have some that works. now with usb download of new bdm software. if anyone want the software that i have already then main me and i will send what i have. The bugs are aprently now that i can't secire the controler. and when i download the code i get an error trying to download to a non excisting area of the prom. i do not know what causes this.