inline asm get pin states pin 0 to 7

Comments

• Electrodude Posts: 1,682

  2014-09-07 16:17 edited 2014-09-07 16:17

  
• Mart1970 Posts: 23

  2014-09-07 16:38 edited 2014-09-07 16:38

  Hello
  
  I wrote a new code.
  i don't know it works.

  __asm__(
               "mov r8, #0xff\n\t"
               "shl r20, #0xff\n\t"
               "andn outa, r20\n\t"
               "mov %[_value], ina wc\n\t"
               : /* outputs */
               [_value] "=r" (value)
               : /* inputs */
               : /* no clobbered registers */
               );
  

  
  Hope this wil work
  I try it out in the morning it's past midnight over here.
  good night.
• kuroneko Posts: 3,623

  2014-09-07 16:55 edited 2014-09-07 16:55

  What's wrong with doing it in C (boils down to 2 PASM insns):

  result = INA & 0xFF;
  
• msrobots Posts: 3,709

  2014-09-07 20:11 edited 2014-09-07 20:11

  DIe schwarze Katze wieder... (@kuroneko again...)
  
  As usual down to the point. I love it.
  
  If life ever brings me down to Japan - I hope I can meet you.
  
  Enjoy!
  
  Mike
• Mart1970 Posts: 23

  2014-09-07 22:13 edited 2014-09-07 22:13

  Kuroneko.
  
  I try it, but i am very critical in time.
  
  Thanks
  
  Mart
• kuroneko Posts: 3,623

  2014-09-08 21:14 edited 2014-09-08 21:14

  Mart1970 wrote: »

  I try it, but i am very critical in time.

  If critical doesn't refer to code speed please ignore this post.
  
  In PASM you'd do the following:

  mov state, ina
  and state, #$FF
  

  with the mask insn being optional when you write the byte to hub anyway (wrbyte does that for you). The C example I gave compiles down to the same sequence. IOW there is no need to go near inline assembly (for something as simple as this).
• David Betz Posts: 14,526

  2014-09-09 02:52 edited 2014-09-09 02:52

  Mart1970 wrote: »

  Hello
  
  How to get pin states from pin 0 to 7 ,
  in simple ide c inline asm.
  
  I found this on the net
  Is this for one pin or can i also use it for mutliple pin's.

  static __inline__ int getpin(int pin)
  {
   uint32_t value[COLOR=#666600];
  [/COLOR]__asm__ [COLOR=#000088]volatile[/COLOR] [COLOR=#666600](
  [/COLOR]                         "getp %[_pin] wc\n\t"
                           "mov %[_value], #0\n\t"
                           "rcl %[_value], #1"
                           : /* outputs */
                            [_value] "=r" (value)
                           : /* inputs */
                            [_pin] "r" (pin)
                           : /* no clobbered registers */
                            );
   return value;
  }
  
  

  
  
  kind regards.

  This looks like code for the Propeller 2. There is no GETP instruction in P1. Also, it would only get the state of a single pin. As others have already pointed out, getting the states of P0-P7 can be done in C directly just as efficiently and more readably then any inline assembly could do. Take the easy approach and let GCC do your work for you! :-)
• Mart1970 Posts: 23

  2014-09-09 08:34 edited 2014-09-09 08:34

  Thanks to all.
  
  
  result = INA & 0xFF;
  Works for me