I have a legacy product with an MC68HC000RC12 that I need to update

[LenAveryt]

Due to certification issues we can't redesign the controller, which we would normally do.

I have 100+ Embedded controllers that use the MC68HC000RC12 that I have to update and support for the next 10+ years.

I found that NXP was supposedly making a 68000 version in the ColdFire series.

How would I find this "replacement" processor?

We have got the code off the EEprom and need a processor that can run it.

Thanks

[TomE]

> I found that NXP was supposedly making a 68000 version in the ColdFire series.

The original Coldfire had an instruction set that was closer to the 68K to assist with migration. I can't remember if it was binary compatible. But that doesn't matter.

That was the MCF5102. That dates from about 1996 (the date on the User Manual Addendum), was a replacement for the 68040 (not the 68000) and had nothing like the same pinout. It has 144 pins.

They DID have an "MCF5102 Evaluation Module" that consisted of one of these CPUs on a board which could be used as a drop-in for a 68040, but that doesn't help you.

What do you mean "update and support" when you don't have the source code? You can't update the code without the source. Do you mean "update the hardware" (make new ones), while using the same (or similar) CPU and binary code? Or do you just mean "repair them and replace parts when they fail"?

One option would be to emulate the CPU in an FPGA or have an ARM chip run an emulation, but that should get you into way worse "certification issues" because that's a big change.

Someone has to tell Management "that's impossible". Those decisions (long term support) should have been made over 20 years ago.

You should check here:

https://www.nxp.com/products/processors-and-microcontrollers/legacy-mpu-mcus/32-bit-coldfire-mcus-mp...

NXP still have some MC68EC000 chips in QFP64 and LQFP64 packages at "END OF LIFE". So if one of them suits electrically and physically, then you'd better make a last-time-buy on them. QUICKLY.

They're QFP64. Your "RC" suffix is a PGA part (what! Why?). Can you get away with making a QFP to PGA adaptor board? Can you change the PCB to take the QFP part? That should be allowable. That depends on whether you're repairing or replacing.

Check the data sheet to try and find the HC and EC differences:

https://au.mouser.com/datasheet/2/302/m68000um-1188140.pdf

Wikipedia says the pinouts are "slightly different", but you might not be using whatever is different:

https://en.wikipedia.org/wiki/Motorola_68000#68EC000

Tom

[TomE]

According to the Signal Diagrams in Chapter 3 of the above User Manual, the 68EC000 doesn't have the "E", "VMA" and "VPA" signals These are the ones that let the 68000 use 6800 peripherals. It doesn't have "BGACK", which should only matter if you're using DMA, and even if you are, a small amount of external circuitry should let you make it compatible. It adds a "MODE" signal that lets it switch between 8 and 16 bit bus modes (so being a 68000 or 68008 as required), and it has an "AVEC" "Autovector" signal that you aren't using, unless you were using the 6800 signals to auto-vector. So they should be usable as long as the board changes or you get or make an adapter.

Tom

[Hui_Ma]

Hi,

Due to 68K products and ColdFire products are quite old and we have no dedicated pin to pin compatible replacement products. Maybe you know, we do not recommend customer to use 68K & ColdFire product for new project/design either. 

We would recommend cusotmer have a look at ARM Cortex M core MCU product, such as i.MX RT crossover MCU and LPC platform MCU. Please refer below link for more details.

i.MX RT Crossover MCUs

General Purpose Microcontrollers

Thank you for the attention.

best regards,

Mike

[LenAveryt]

This is for systems that we can't redesign. we have to repair and replace these as we can.

This is why we need original parts or parts that can be adapted.