Those wonderful hardware people ....

emalund · ‎2012-09-27

Posted on September 27, 2012 at 18:12

.... substituted a 64 pin for a 100 pin f105 and 'forgot' to put a pull-up on a pin for me to 'see' which model. Of course, they built a lot of them before I found out.

unfortunately there are no useable PD or PE pns to check (all are NC) and PA, PB and PC are wired identically. Basically the two hardwares (besides chip pibn count) are identical.

now, while the 100 pin is built as 'model x', the 64 pin has be built as 'model y' to match what it is working with. To avoid download in the field of the wrong software, I need to identify the hardware.

anyone have an idea how to distinguish which chip?

Erik

emalund · ‎2012-09-27

Posted on September 27, 2012 at 18:14

ah, a thought

is it defined what you get if you set up and read a port pin that does not exist on the chip?

Erik

Tesla DeLorean · ‎2012-09-27

Posted on September 27, 2012 at 22:43

is it defined what you get if you set up and read a port pin that does not exist on the chip?

Those pesky ST dudes packaging the same die in multiple form factors.

For unbonded pins they are just going to float, I doubt there is any loop-back internally for you to recognize. You could drive the pull up/down in different directions, and observe the stuck-at states.

You should be able to read the RAM/FLASH sizes. Other variants you can check the stuck-at bits on the APB1/APB2 peripheral clock registers. This won't help for identical die.

You could perhaps ground some pins on the 100-pin device, and use the internal pull-ups to probe the GPIO state.

You could perhaps float some solder over multiple unused pins (play with the solder mask, stencil, or whatever), and then perform a loop back test on those pins to confirm a physical connection.

Tips, Buy me a coffee, or three.. PayPal Venmo
Up vote any posts that you find helpful, it shows what's working..

David Littell · ‎2012-09-28

Posted on September 28, 2012 at 15:43

Wow. Just wow. I had to read your post multiple times to try to make sure it wasn't some obscene joke.

I haven't seen anything more monumentally stupid in quite a while. My first question is are you now looking for a new job? If not, why not? You can't work with idiots like this for too long before they grind you down and poison your thinking. What conga line of morons was involved in even considering that change without checking with you?

My second question is why are you working so hard to make it easy for them to skate through this? My response would be along the lines of, ''You obviously worked really, really hard to create this problem, how are you going to resolve it?'' If you get yelled at, yell back. Remember that hardware guys alone create nothing more than paperweights and dust magnets. It's the software that makes the product. I've forced changes that cost thousands because there was no other way. Deal.

emalund · ‎2012-09-28

Posted on September 28, 2012 at 16:45

Clive,

You should be able to read the RAM/FLASH sizes.

This would work if ST (and most others) did not have the habit of, occasionally, labeling a 512k device with a 256k part number

You could perhaps ground some pins on the 100-pin device, and use the internal pull-ups to probe the GPIO state.

as stated, they have made a lot of boards

Dave,

I haven't seen anything more monumentally stupid in quite a while. My first question is are you now looking for a new job? If not, why not? You can't work with idiots like this for too long before they grind you down and poison your thinking. What conga line of morons was involved in even considering that change without checking with you?

My second question is why are you working so hard to make it easy for them to skate through this?

this is how a consultant, such as me, makes his money :)

Erik