Assembler-Inputs

Regular Guy · Joined: 04 Jun 2017 Posts: 110

Any words of wisdom?

16F84A

Microchip Picdem 4

Microchip ICD2

MPLAB 8.40

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

Read the Microchip PIC16 Reference manual section on i/o ports:
http://ww1.microchip.com/downloads/en/devicedoc/31009a.pdf

Ttelmah · Joined: 11 Mar 2010 Posts: 19506

But, also I have to ask 'why'?.

It has reached the point now, where it is possible to do pretty much
everything that can be done using assembler, directly in C, with no
extra overhead. To the point now, where I'd say "don't bother with
assembler", for 99.99% of situations.

temtronic · Posted: Sat Sep 05, 2020 5:08 am

Mr. T asks 'why' ?

some reasons I can think of..

1) better understanding of HOW a PIC operates. By programming in Assembler you're as close to 'playing computer' as is possible ! High level languages 'mask' or 'hide' HOW things are done. Depending on how a 'function' was coded it might take longer or use more space than being done in Assembler. The better you understand how a PIC works, the better you can program it.

2) easier to learn.OK, I'm ready for the replies.... but PIC's only have 30-35 instructions far, far less than any version 'C' or other high level language. Once you learn the 'basics', you'll quickly build your own library of functions.

3) speed and size. Generally Assembler will create smaller, faster programs. While the CCS compiler is very smart and can 'optimize' code, handcoding in Assembler can SHOW you how to make 'better' programs. Today's PICs have LOTS of memory, speed and internal peripherals but in the 'good old days' you HAD to understand the PIC to take advantage of every bit of every byte, learn how registers work, etc. Microchip printed 'Tips and Tricks' filled with clever code to maximize PIC performance. Early application notes showed how to 'do the impossible'.

4) Comments ! When cutting code in Assembler, you almost always add a comment at the end of every line of code. It's an EASY way to figure out the next day WHY you did this or that. Even better, days or months later, you can READ why you did it, saying 'gee that was clever or grr..that was silly, I should have coded.....'

I started with the 16C84 and Assembler, then bought PCM v2.534, self taught myself CCS C, so I'm NOT a C programmer I kinda bodge this into that, getting programs to work. I only 'play with PICs' today, SMT is too small, heck DIPs are difficult to see too ! Pre-made 'Modules' are nice though !!

dluu13 · Joined: 28 Sep 2018 Posts: 395 Location: Toronto, ON