Info on MC68HC08AB16A

[knoweyedeer]

Hi all,

G'day guys, I'm new to these forums.  I am a university student and I have the distinct pleasure of doing a research assignment on the MC68HC08AB16A microcontroller.  I am first year so my questions will not be as demanding as the pros here might be used to, so I appologise in advance.  The upshot of course would be that you may not find my questions particularly demanding

The problem I am facing is that I cannot locate the information I require on the datasheets.  The other problem I am facing is that all my answers must be refferenced to datasheets so I cannot make any assumptions.  Hence the dilema.....

So here is the first of what I think could be many questions:

Q) Does the microcontroller have support for external memory? If so, what is the maximum amount of external memory that can be supported?

A)Modular architecture with expandable internal bus definition for extension of addressing range beyond 64K-bytes  ref: MC68HC08AB16A — Rev. 2.1 sect 7.3 pg 82

That is my current answer, which I am sure is incorrect, it also doesn't answer the second part of the question.  Any help you can give me will be greatly appreciated.  Cheers, Tony.

[Ake]

Hi,

I am a bit suprised that you have selected the HC08AB16A as a student project.

The HC08AB16A is a ROM based product, which means that to get an MCU programmed,  you must enter the code to Freescale and enter the MOQ, minimum order quantity, which usually is 1K - 5K pieces.

Usually if there is a HC08xx MCU, you can buy an identical HC908xx but with Flash EPROM on the chip.

The device that you should use is a device called HC908xx or 9S08xx.

I would prefeer to use the 9S08xx in your kind of project because it offers better debug support.

The reference about extended architecture beyond 64 K in the MC68HC08AB16A, is something that has never been used in the HC08 world, so it is of no interest at all.

My advice is that you look at the

http://www.freescale.com/webapp/sps/site/taxonomy.jsp?nodeId=01624684491437

for a 9S08 that will suit your needs.

Regards,

Ake

[knoweyedeer]

Thanks for the reply Ake.  I didn't get to choose what I was meant to research.  I see that the device you suggested would be better, if I was planning on actually using it.  My research assignment consists of answering a bunch of ambiguous questions using datasheets as my source.  At no point will I be buying any processors, nor will my school.  We use the atmel avr 8515 which is not nearly as good as this particular device, however, if you are going to teach a bunch of first year students how to code and get a device working, best to use something cheap.  Anyhow, if anyone knows the answer to my question, whether its of interest or not, I would be greatly indebted. Cheers, Tonez