Hidden TPM channel in 32-pin GT16A

[OldMan]

Hi,

32-pin MC9S08GT16A has no IO pin for TPM2CH1. But I think I can still use TPM2CH1 in the capture mode to generate interrupts. Both the gates and the pad for TMP2CH1 are on the silicon, just there is no pin that connects to that pad. Right?

My question is, can I use TPM2CH2, -3, -4 this way? Is it possible that the gates are all there, but no pads or pins to bring them out?

Any insiders' hint?

-- OldMan

[peg]

Hi Oldman,

No secrets here.

As I have said many times in this forum, a GT is just a GB with less pads on the chip bonded out to actual external pins. All the GB functionallity is there just the external pins are not!

You have to treat the non-bonded out I/O as you would unused/unconnected real pins.

e.g. make them outputs or enable their pullups etc.

Regards

Peg

[peg]

Hello,

I think my previous answer is not quite correct.

What I said is correct, but as it appliess to the question is possibly not.

This is what I think the story is:

Non-A GB/GT parts all contain the same silicon, just different amount of pins bonded out and different amounts of flash.

All A parts have dedicated silicon to suit the highest pinout package. The registers are cut back to suit.

So the correct answer to the question would be that yes you can use TPM1C2 and TPM2C1 even though you don't have pins for them but TPM2C2,3&4 are not available.

I don't have any A silicon to try this out, so, let us know what you find.

Regards

Peg

[OldMan]

Peg,

Thank you for your responses. Especially the follow up!

Best regards,

--OldMan

[peg]

Hello,

Also if I am indeed correct about this then this information should be included in the non-A to A migration documents EB671 and EB652 etc.

This would pose a migration issue for anybody that was using the parts of the registers that have been dropped.

Regards

Peg