Serial I/O with a Motorola MC68HC11E1 MCU

I've got a Motorola MC68HC11E1 microcontroler with a small program on it. What I need to do is write a GUI interface to upload config data to certain memory locations and download stored data from other memory locations. I can do serial I/O in MFC but I need to know how to read/write to memory locations on the Microcontroler through the Serial Communications Interface. Even more basically will the MCU do this or do the upload/download routines need to be written into the onboard program?

Answers, references, suggestions, and/or comments appreciated.
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

The 68HC11 has a programmable UART (i.e. serial port interface) implemented in it's hardware.  In order to do what you want, however, you must write a program that runs on the 68HC11 that will watch for and accept commands from your Windows program to read/write memory locations and do whatever other tasks you want it to.  Rather than spend a lot of time writing a custom Windows application to do this, why not just use Hyperterminal (which is included with Windows)?  

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
beyondrobAuthor Commented:
We've got a program (PCBUG11) that interfaces with the microcontroler already. From the documentation it uses motorola's S-records. We are planning on doing it this way right now and emulating the basic program that came with the documentation to upload the data. Do you see any problem with approach?

I'm doing the Windows program since the config will be being used by not technical people who need a simple UI to work with.
I understand now why you want to write a Windows GUI.  Using PCBUG11 (or a modification of it) should be straightforward.
Big Business Goals? Which KPIs Will Help You

The most successful MSPs rely on metrics – known as key performance indicators (KPIs) – for making informed decisions that help their businesses thrive, rather than just survive. This eBook provides an overview of the most important KPIs used by top MSPs.

beyondrobAuthor Commented:
The problem is is that I don't (didn't) have an Idea of how PCBUG11 did what it did. I'm hoping the S-Records are the key. I'm going to give you the points I just wanted to get in some comments while I could to make sure I wasn't going about it all wrong.
There is nothing magic about Motorola S record format.  It's been around since the original MC6800 development kit.  It is supported by almost all embedded processor compiler/linkers and also my almost all EPROM programmers.  If you need details on the format, I'm sure I can dig something up for you.  Im sure that the PCBUG11 program is just a simple debug monitor program that is designed to help debug a 68HC11 embedded system.  Since these systems don't typically have any kind of UI or console, a tool like PCBUG can help you out a lot.  It just watches for commands on a serial line and does what you tell it to do.  Usually you can do things like examine memory, set locations, toggle IO ports, set breakpoints, and start a program executing.

I haven't used PCBUG11 myself, but I have used many other similar tools.  Even wrote one for the 6502 when I worked for Rockwell Intl. back in the 1980's.
beyondrobAuthor Commented:
If you've got any info on S-Records, the MCU, or how PCBUG controls the MCU over the serial port it'd be much appreciated. I need to know what the commands over the serial line are so I can make my program do them.
ok I have the same kit
we first faced the problem of uploading your assembly program via kermit from win95
the solusion was to reboot and start this from dos

as a result I was not encouraged to make any interface for the kit on win95

It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.