topic Freescale assembly Language in 8-bit Microcontrollers

Freescale assembly Language

venki — Wed, 04 Apr 2007 14:04:48 GMT

Hi,

I want to learn Freescale assembly language.Pls let me know where i get instruction sets with explanation of each.

Venki

Re: Freescale assembly Language

peg — Wed, 04 Apr 2007 15:21:01 GMT

Hi venki,

As you posted another question about the GP32 assume this is what you are talking about here.

This document provides the best start in this case:

http://www.freescale.com/files/microcontrollers/doc/ref_manual/M68HC05AG.pdf?fsrch=1

Re: Freescale assembly Language

bigmac — Wed, 04 Apr 2007 21:05:11 GMT

Hello Venki,

The reference given by Peg actually pertains to the nearly obsolete HC05 devices. While HC08 assembly programming has similarities, and is backward compatible with the HC05, there are also a considerable number of differences that can simplify the code. A complete reference to the newer instruction set may be found in the document, CPU08RM reference manual. This also contains assembly programming examples.

http://www.freescale.com/files/microcontrollers/doc/ref_manual/CPU08RM.pdf?fsrch=1

If you were to consider the newer HCS08 devices, there are some further enhancements over the HC08, but the differences are fewer. These are outlined within application note AN2717 "M68HC08 to HCS08 Transition".

Regards,

Mac

Re: Freescale assembly Language

Curt — Fri, 13 Apr 2007 07:55:32 GMT

Hi venki

I'd say: pick a processor and buy a development/demo kit for it that comes with the

Freescale CodeWarrior IDE. You'll have everything you need to learn the assembly language in one package -- and a hardware platform to experiment with.

Or if that's too expensive for you right now (been there!) -- download the CodeWarrior special edition that supports the 'S08 seriec of Freescale components and learn the language via the full-chip simulator built-in to that IDE.

You'll be an expert before you know it!

Re: Freescale assembly Language

venki — Tue, 17 Apr 2007 13:57:40 GMT

Dear Peg,

Pls let me know what the below code does

MOV #$01,$42

Regards

Venki

Re: Freescale assembly Language

Alban — Tue, 17 Apr 2007 15:32:52 GMT

Hi Venki,

This is where you need to look into the S08 CPU Reference Manual advised by Bigmac.

MOV means "move"
# means immediate value.
$ means hexadecimal.

So MOV #$01, $42 means put the value "1" at address 0x42.

Cheers,
Alban.

Re: Freescale assembly Language

peg — Tue, 17 Apr 2007 17:03:45 GMT

Hi Venki,

What Alban said is correct, However if we are still talking about the GP32 you are better looking at

CPU08RM.pdf to find out what MOV does, and

MC68HC908GP32.pdf to find that $42 is just an address in the RAM.

So what it actually does is up to the programmer.

Re: Freescale assembly Language

venki — Tue, 17 Apr 2007 19:32:50 GMT

Dear Peg,

Pls go through attached file & help me .

Regards

Venki

Re: Freescale assembly Language

bigmac — Wed, 18 Apr 2007 00:31:03 GMT

Hello Venki,

Within your code snippet, there are tests for a total of five different timing events, presumably the result of a periodic timer interrupt.

The first timing event utilises a word value at RAM address $45, used as a counter, and a further word value at $47 that contains the address of a sub-routine to be executed in the event of timeout. The contents of these registers will have been setup elsewhere within the program, likely outside of the interrupt code. You will need to search for the other locations that write to these registers to identify what the timing events actually mean.

The processing of the timing event -

Test counter value ($45/$46), and if non-zero, decrement the value - otherwise skip to next event.
Test new counter value, and if zero (timeout), continue with current event - otherwise skip to next event.
Test sub-routine address value ($47/$48), and if zero (invalid address), skip to next event.
Execute sub-routine (JSR ,X).

Each timing event follows a similar pattern, although the code is not quite identical, presumably because of the compiled C origins.

Regards,

Mac

Re: Freescale assembly Language

venki — Wed, 18 Apr 2007 14:41:17 GMT

Dear Mac,

Pls find attached file & give your comments

Regards

Venki

Re: Freescale assembly Language

venki — Tue, 24 Apr 2007 12:47:52 GMT

Dear Mac,

I want to start learning Embeded C.Pls help me.

Regards

Venki