Selecting a micro controller

[SreekumarC]

I chose S08 microconroller for my Automotive Lght Control System. But it sounds a problem with the code size and timing issues.  I am thinking of any 32 bit microcontroller, it may solve these issues. Can you suggest a better option.?

[JimDon]

Well, for one thing, it is hard to make a sensible recommendation from what you have said.
The application you have mentioned could range from pretty simple to very complex.

I will say the Flexis line offers one of the widest range of compatible options. If you were to  start with and 08, and find you over run it, you can move to a 32 bit cold fire almost seamlessly.

"But it sounds a problem with the code size and timing issues."
Where did you hear that? Why do you say that? The HCS08 ranges from 2k parts to 128K parts, with up to  50MHz clock frequency. The 32 bit part offers 10-12 times the performance.

So tell us more about your application.

[SreekumarC]

Thank you Jim,

My application is an Front light control system according to different driving conditions(on turning, in night, high beam and low beam etc).

Software include an algorithm and device driver. I didn't know how much time the algorithm takes and time to do the light adjustments. But S08 sounds like insufficient and can you compare the timings of S08 and any 32-bit processor.

Sreekumar

[bigmac]

Hello Sreekumar,

I still think you don't have sufficient information to make a choice.  Why do you say that the S08 "sounds insufficient"?  Here is a list of further questions for which you will need to seek answers, to get a better feel for what is required.

1. What quantity and types input signals from external sensors are required?  How many times per second does each sensor need to be sampled?
2. What type of output signals are required to control the headlamps and other items, and how many control channels are needed for this purpose?  How many times per second does the control data need to be updated?
3. Does the precision required demand use of floating point numbers?  Is the use of non-linear functions, such as trigonometric or logarithmic, required for the processing?
4. Does the data analysis require use of FFT, etc.

As Jim D. mentioned, the 9S08QExxx series may be a reasonable choice, because it allows a direct migration path from 8-bt to, 32-bit Coldfire, using peripheral modules common to both devices.

Regards,

Mac