We have a 32 bit ( mcf51 series ) project that is overkill for what it does. We want to do a low cost version of the same product. We can do all of the project with an rs08 series microcontroller but are a little wary of using one due to to the life left in this series. Do people have advice on what to do ? We dont want a lot of work from a code standpoint or learning curve standpoint. We have a good code base we would like to take advantagesof. We need low cost. Maybe 50 cents a micro is what we want. Is there something else we should consider ? USe the RS08 ? We would liuke to get 5 years life of product.
Also, I checked this morning and it appears the Kinetis is consistently 0.30 cents more than the HC08 and none of the distributors I use ( IE digikey, etc) dont seem to have many or any of the lower end processors of the lines you mention in stock. They seem to have lots of the 08 series. Any insight would be helpful
S08P is the latest family of S08 devices. It is perfectly recommended for new designs. As well as Kinetis L family, which is completely launched and available now.
If S08PA fits your requirements, the price will be less than a Kinetis L family. It is your choice to keep your code/project in the 32 bits world (The future of MCU will follow this path) or to use a 8 bits MCU for the next few years.
And there is the new family, Kinetis E, which is pin to pin compatible with S08P, just in case you want to migrate in the future your design to 32 bits again.
As a general statement, I would personally encourage designing with the 'latest' processor family, and put up with a few 'bleeding edge' difficulties to do it (like initial cost and availability).
But in any case any selection of microcontroller really has to start with an assessment of the project needs. How many 'user function' pins will be required? What are the particular peripheral-module requirements (especially anything 'in particular' like CAN or LIN)? Then we need an 'honest guess' of FLASH and RAM requirements, and an overall goal for total MIPS. It takes all that to make a 'cost effective' recommendation for chip choice.