8-bit MicrocontrollersのトピックRe: ASM SCI code for HC08LB8

ASM SCI code for HC08LB8

rceit — Wed, 15 Mar 2006 00:05:50 GMT

Hello Encoder

The HC908LB8 do not has SCI module, i am looking in the web for the software but i do not meet. I want asm software for implement it in my code, also i have free master sotware. With all this(free master, SCI sotf and C code warrior for LB8) i want to degug in-circuit in real-time, i want run my application and monitoring RAM variables. It is possible? where i can meet asm soft?

Thanks and best regards.

Re: ASM SCI code for HC08LB8

rceit — Wed, 15 Mar 2006 00:55:54 GMT

The message is for all , not only for Encoder.Sorry.

Re: ASM SCI code for HC08LB8

Encoder — Wed, 15 Mar 2006 06:50:55 GMT

Hallo Rceit,

I don't know why you chosen 908LB8, perhaps some specific feature non easely found on other HC908, like high resolution PWM or the op-amp/comparator module.

If this is not the case, I would avoid as possible choosing a uC without an embedded SCI or ESCI module. Freescale has a lot of models to choose from which seems to be better equipped for the price of LB8.

Not talking about the foreseen 908QC16 which is plenty of all sort of good things and less costly but unfortunately not available, many other models are eligible. In the same size bur slightly cheaper, I would consider the JK8: more ram, more ADC lines, more timers and a SCI port...

With few more or many more pin and much more modern and powerfull features but nearly the same price or less I would consider JL8 or the AP8, both incorporating a SCI port.

It is surely possible to write a software simulated SCI at a low baud rate for the LB8: AN1818, AN2502 and AN2637 provides the best approach to the problem, with functioning ASM and C code. But I would avoid it as the hell...

I don't know your resources and skill but debugging on low power evaluation boards with the embedded CodeWarrior simulator and debugger may prove long, difficult and frustrating. If you have not a high volume application which amortize the cost of this task, it would be far better to spend a little more on uC with an embedded SCI. And, as previously said, you are not obliged to pay more: even the small, cheap 16-pin 908QB8 is a dream in paragon. Its embedded ESCI may be even 20 times faster than a software based SCI and much less CPU-intensive. Do not underestimate the SCI protocol too: my first thread on ASM SCI interrupt driven routines for HC08 proves that it is not such trivial even on uCs which incorporate an hw SCI or ESCI.

In conclusion: if you are decided to go ahead refear to the cited application notes, if not change the uC!

Good luck

Encoder

Re: ASM SCI code for HC08LB8

rceit — Wed, 15 Mar 2006 17:17:16 GMT

Thanks Encoder for your help, my application is for fluorescent lamps and need the dedicated modules of LB8. The problem now is how can i inplement the AN1818 code in my structure of code warrior files, i make copy from the .pdf and paste in a new folder (named Sci) in the code warrior structure folders, but this do not compile.

Thanks and best regards.

Re: ASM SCI code for HC08LB8

Encoder — Wed, 15 Mar 2006 21:04:03 GMT

I didn't tried to make a synthetic SCI for the reasons previously pointed out but I suppose it is not a trivial task.

I don't think you can simply cut-and-paste the 705P6A code on AN1818 to use it on 908LB8. Perhaps a better one could be the 908JK3 code on AN2502, which closer resembles your CPU, if you may use both channels on the timer.

Moreover, whilst not a major problem, both codes appear to be in another ASM format than that used by CodeWarrior and you need to do some simple translaction at least on declarations other than some specific tayloring to your application.

Sorry, I can't help in that.

Re: ASM SCI code for HC08LB8

rceit — Fri, 17 Mar 2006 00:42:59 GMT

Thanks you Encoder, i going to try with the AN2637 application note.