PIC Microcontroller Program Flow Methods

• See: Instruction Listing, GOTO, CALL, Paging
• Register <, >, <=, or >= a constant or a register
• Test if a value is in or out of a range
• Test if a value is a power of two
• Conditionally replacing one value with another
• Tony Nixon's 8 and 16 bit comparison quick reference
• Multitasking / Context Switching
• Handling flags or boolean variables
• Forcing a hardware reset and detecting the cause of a reset/restart
• Detecting a change in a port, timer, etc...
• String matching
• Sorting
• Code generator  for keyword matching from a serial text stream by Nikolai Golovchenko Wow!
• New 18Cxx2 functions
  • Function pointers (like in "C")
  • Unlimited computed goto (or table lookup)
  • Multilevel returns
  • Exception handling (like in C++) (or C's setjmp/longjmp)
  • Co-routines/cooperative tasks with mainline cocalls only
  • Co-routines/tasks version allows all cocalls
  • Preemptive real-time multitasking kernel

• See also:

  • http://websites.ntl.com/~matthew.rowe/micros/virbook/logic.htm routines from Andrew Warren
  • http://www.seanet.com/~karllunt/picmacro.htm Karl Lunts PIC Macros (FOR...NEXT, CASE, REPEAT, POLL, WAIT, etc..) (cached 20000317)
  • http://www.actum.com visually edits state diagrams and outputs PIC assembly code.

Archive:

• List post "Beginner assembler questions concerning loops and conditionaljumps" +
• PICList post "how to compare two numbers" +
• PICList post "Compare 4 number method. Please help!"

See also:

• David A Cary refers to

  http://www.microchipc.com/Hi-Tech_C_speed_optimization.htm Is there a page on massmind somewhere that shows the (assembly-language) skeletons of various kinds of loops ?
  kinds of loops:
  (#of iterations not known before the last iteration) do...while(), while()...loop, (#of iterations known at run time before loop starts) do_N_times, (#of iterations known at compile time) do_10_times, ... any others ?
  (... mention counting *down* to 0 optimization ...)

• swstmt.htm Choosing between 3 or more alternatives: ``switch...case...default'' AKA ``select...case'' AKA ``case..of''.
• multitasking.htm Multitasking / Context Switching

Questions:

• Is there any way to use the "if" command not as a conditional assembly command, but actually as you would use it in C or Java while your programming in assembly?
  See Karl Lunts PIC Macros listed above

Comments:

Peter Todd has released source and sample projects for his artwork, including his 3d wireframe cube renderer for the PIC 18f6520 This includes examples of hardware developed with free software tools such as gEDA/gschem/PCB, SDCC, gputils and picp all on Linux. http://petertodd.ca/art/source-code/

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