CCS plus assembly

[Arakel]

Good day! I have a question that I am trying to figure out. Is there any way to include Assembler code in CCS? Sometimes the functions of CCS are not very efficient and they cause problems do to bugs, the best way that I can think of to overcome this, and it probably always works is to add an Assembler instruction in the code.
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Yo! I love learning and technology! I just do not have experience so do not be angry if I ask a stupid question about a detail! From so much to remember sometimes I forget the details in order to remember the big problems!

[Ttelmah]

Look at ex_glint.c
ex_fir.c (PCD)
ex_macro.c

Each shows a small piece of assembler being included in the CCS code.
99% of such functions can be coded without using assembler. #byte and #word to talk directly to SFR's etc..
The CCS assembler allows C variables to be accessed by name in the assembler. The command list is in the manual.

[Arakel]

Thank you! You deserve a beer!
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Yo! I love learning and technology! I just do not have experience so do not be angry if I ask a stupid question about a detail! From so much to remember sometimes I forget the details in order to remember the big problems!

[temtronic]

While Mr T's comment about coding functions in C vs Assembler is true, you may be able to 'refine' a C function. Some programmers code for speed, others for compact code, others don't seem to do care and create 'bloatware'.
When you cut code in Assembler you have a better understanding of what's happening 'inside the PIC'. Microchip has several 'Tips and Tricks' books, where simply resequencing the code or thinking 'upside down' can save bytes or microseconds.
In the good old days of 2Mhz clocks it was important, not so much now with 64Mhz speeds, however if you want clean,tight code, it's worth investigating HOW code works.

Jay

[Arakel]

This is useful also, and I like Microchip, the direction in which they work should continue and not stop! They are doing things right! But I just dont have the time at the moment to read a 600 page datasheet or 6000 page book. Plus I have to read Kernighan and Ritchie, and I should some day.
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Yo! I love learning and technology! I just do not have experience so do not be angry if I ask a stupid question about a detail! From so much to remember sometimes I forget the details in order to remember the big problems!

[jeremiah]

[Arakel]

I understand that, this is the very reason why I first must read what I have now and then continue forward.
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Yo! I love learning and technology! I just do not have experience so do not be angry if I ask a stupid question about a detail! From so much to remember sometimes I forget the details in order to remember the big problems!

[newguy]

The only thing that I've done which has required the use of assembly is getting a PIC to boot from its internal oscillator and then doing an immediate switchover to an external crystal. The necessary registers are locked and can only be accessed once a special time sensitive unlock sequence is generated, and that's what I used assembly for. For everything else - plain old C suffices, especially given that you can directly access special function registers very easily.

Just remember that C is portable; assembly isn't. Just the other day I actually had someone ask my opinion about keeping all their specialized IP, created over the past 2 decades, which is entirely written in assembly. ...For an obsolete family of processors. I don't think they particularly liked my answer, but to me there's really only one alternative: start fresh in C. At least with C you have a relatively easy migration path in future. With assembly, if you change processor families or change manufacturers, all your IP is quite useless.

[Arakel]

They still use assembly, especially for mainframes, I dont think that they change the manufacturer, but especially It might have been for the mainframes used the by US emigration service, they use assembly.
_________________
Yo! I love learning and technology! I just do not have experience so do not be angry if I ask a stupid question about a detail! From so much to remember sometimes I forget the details in order to remember the big problems!

[temtronic]

just a note... not all C is the same ! We've all seen C code presented here, from another compiler, that will not work as written in CCS C. There's always tweeks to be done.
Every high level language has 'variations' though the closest to 'universal' or machine/OS independent I seen was COBOL. Once you entered the machine/OS specifics in the first section (say 10-20 lines), the 'main' program would compile and execute on any machine from an IBM mainframe to the lowly TRS80-II.

Jay

[Ttelmah]

It's worth saying, that I have things like the unlock sequence, and things like flash I/O routines, that exactly match the data sheet, but are coded in C....

'Core' C, will 99.9% translate between almost any compiler (with the limitation of being 'aware' of data sizes). However we are writing in 'embedded C', which implies working directly with some parts of the chip, rather than relying on an 'OS' outside. Exactly the same is true of any language. Even languages like Pascal, when you get involved in directly accessing hardware, customisation for the machine becomes necessary.

Historically, perhaps ten years ago, a lot of CCS code would involve some assembler sections. Nowadays the need for these is getting less and less. However there are still the odd 'tiny' part, where it cleaner, safer, & probably quicker to write, in assembler. Sometimes there are little parts of the initialisation or setup, where the default is very 'safe', but often over complex....

[newguy]

[gjs_rsdi]

Used assembler with CCS when I had no choice.
With my old CCS compiler and PIC18F2520 was a problem using

[Ttelmah]

However that doesn't need assembler:

[gjs_rsdi]

As I suppose you know from my questions Ttelmah, I am not really a C programmer
Just not long time ago learned that I can use "getenv" for certain things.
So using assembler to overcome the bug was natural to me

Best wishes
James