avr hardware pins acces from pascal[SOLVED]

[diego bertotti]

hi, im trying fpc/lazarus to avr/arduino and it works! thank you. thank you thank you very very much!!!

but, if we don`t forget the atmega328 is a microcontroller, maybe a bit oriented view will be mandatory

when you need test a pin status , we need to read a whole port, and them mask the wanted bit, and the assembler generated don`t seems efficient (i guess).

when you need to output a bit, the assembler generated is good, but you may type things like that:

Code: Pascal  [Select][+][-]

1.  
2. PortB:= PortB AND %11111011;
3.  
4.  

then assembler generated is: cbi 5,0--its ok! but you must type a whole line!!

or another example

Code: Pascal  [Select][+][-]

1.  
2. PORTB :=PORTB and not ( 1 shl 5 ) ;  // LED pin5 off
3.  
4.  

with a native new class "bit", may will can access bits more directly like turbo51 does for 8051 microcontroller:

example:

Code: Pascal  [Select][+][-]

1.  
2. P2.5:= true; //set bit 5 of port 2
3.  
4. if p2.5 then p2.4:= false; //if pin 5 of port 2 is set, then clear pin 4 of port 2
5.  
6.  

i looking the assembler instructions set of avr it can be do it (i guess)

again thank you very very very much!

[ttomas]

You can use bit packed record TByteBits
http://wiki.freepascal.org/Bit_manipulation

[avra]

Follow links from this post:
https://forum.lazarus.freepascal.org/index.php/topic,43923.msg308285.html#msg308285

[diego bertotti]

Thanks for replys

Maybe i don't be clear enough. My apologies. Its about assembler code generated by compiler, then only apply to avr.

And also to shortened the typed string. Im lazy

Maybe bitpacked will work. Ill try

I dont found documentation specific of avr feeepascal
Thanks again

[diego bertotti]

i Found IT!!

Code: Pascal  [Select][+][-]

1. Var
2. PuertoD: bitpacked array [0..7] of boolean absolute PORTD;
3.  
4.  
5. begin
6.  PuertoD[5]:= true;
7.  PuertoD[5]:= false;
8. end;  
9.  
10.  

and the generated assembler code was:

Code: Pascal  [Select][+][-]

1.         sbi     11,5
2.         cbi     11,5
3.  

For output. Great news.. it work very well!!

remain found the way for read input bits!!

[diego bertotti]

and another aproach!

Code: Pascal  [Select][+][-]

1. var
2. PuertoD: bitpacked array [0..7] of boolean absolute PORTD;
3. PinesD: bitpacked array [0..7] of boolean absolute PinD;  
4.  
5. begin
6.  PuertoD[5]:= true;
7.  PuertoD[5]:= False;
8.  If PinesD[1] then
9.   begin
10.   PuertoD[5]:= False;
11.   end;
12. end.
13.  

and assembler was....

Code: Pascal  [Select][+][-]

1.         sbi     11,5
2.         cbi     11,5
3.         in      r18,9
4.         sbrs    r18,1
5.         rjmp    .Lj95
6. .Lj94:
7.         cbi     11,5
8. .Lj95:
9.        
10.  

excellent! but for brach/ jump (if statement)

[diego bertotti]

hi

im back

in last example, assembler use IN instruction to move port data to a r18 register, and then test bit. Will be better use branch instruction reading real port pin.

¿anybody know who can change this in the avr compiler?

where can i make contributions?

thanks

[Laksen]

I just added that to trunk.

[diego bertotti]

I just added that to trunk.

hi
thanks laksen!
how i can know when update/fix is online?
again, thanks

[sstvmaster]

Here you can see the changes to trunk and so on: https://svn.freepascal.org/cgi-bin/viewvc.cgi/

Here is laksen's change/patch: https://svn.freepascal.org/cgi-bin/viewvc.cgi/trunk/compiler/avr/aoptcpu.pas?view=log

[diego bertotti]

thanks sstvmaster

[diego bertotti]

hi

congratulations!!!

for this pascal code

Code: Pascal  [Select][+][-]

1.    If Not PDin[2] Then PBout[0]:= True else PBout[0]:= False;
2.    If Not PDin[4] Then PDout[7]:= True else PDout[7]:= False;
3.    If Not PBin[5] Then PDout[6]:= True else PDout[6]:= False;
4.    If Not PBin[4] Then PDout[5]:= True else PDout[5]:= False;
5.    If Not PBin[3] Then PCout[0]:= True else PCout[0]:= False;
6.    If Not PBin[2] Then PDout[3]:= True else PDout[3]:= False;
7.  

now the compiler generated assembler is:

Code: Pascal  [Select][+][-]

1. .Lj80:
2.         sbic    9,2
3.         rjmp    .Lj57
4. .Lj58:
5.         sbi     5,0
6.         rjmp    .Lj59
7. .Lj57:
8.         cbi     5,0
9. .Lj59:
10.         sbic    9,4
11.         rjmp    .Lj61
12. .Lj62:
13.         sbi     11,7
14.         rjmp    .Lj63
15. .Lj61:
16.         cbi     11,7
17. .Lj63:
18.         sbic    3,5
19.         rjmp    .Lj65
20. .Lj66:
21.         sbi     11,6
22.         rjmp    .Lj67
23. .Lj65:
24.         cbi     11,6
25. .Lj67:
26.         sbic    3,4
27.         rjmp    .Lj69
28. .Lj70:
29.         sbi     11,5
30.         rjmp    .Lj71
31. .Lj69:
32.         cbi     11,5
33. .Lj71:
34.         sbic    3,3
35.         rjmp    .Lj73
36. .Lj74:
37.         sbi     8,0
38.         rjmp    .Lj75
39. .Lj73:
40.         cbi     8,0
41. .Lj75:
42.         sbic    3,2
43.         rjmp    .Lj77
44. .Lj78:
45.         sbi     11,3
46.         rjmp    .Lj50
47. .Lj77:
48.         cbi     11,3
49.         rjmp    .Lj50      
50.  

[dseligo]

I know it is old thread, but why with this code bellow I don't get same results:

Code: Pascal  [Select][+][-]

1. Var
2.   PDin: bitpacked array [0..7] of boolean absolute PIND;
3.   PBout: bitpacked array [0..7] of boolean absolute PORTB;
4.   PDout: bitpacked array [0..7] of boolean absolute PORTD;
5. ...
6.   If Not PDin[2] Then PBout[0]:= True else PBout[0]:= False;
7.   If Not PDin[4] Then PDout[7]:= True else PDout[7]:= False;

I get:

Code: ASM  [Select][+][-]

1. # [109] If Not PDin[2] Then PBout[0]:= True else PBout[0]:= False;
2.         lds     r18,(41)
3.         sbrc    r18,2
4.         rjmp    .Lj17
5. .Lj18:
6.         rjmp    .Lj16
7. .Lj16:
8.         lds     r18,(37)
9.         ori     r18,1
10.         sts     (37),r18
11.         rjmp    .Lj19
12. .Lj17:
13.         lds     r18,(37)
14.         ldi     r26,-2
15.         and     r18,r26
16.         sts     (37),r18
17. .Lj19:
18. # [110] If Not PDin[4] Then PDout[7]:= True else PDout[7]:= False;
19.         lds     r18,(41)
20.         sbrc    r18,4
21.         rjmp    .Lj21
22. .Lj22:
23.         rjmp    .Lj20
24. .Lj20:
25.         lds     r18,(43)
26.         ori     r18,-128
27.         sts     (43),r18
28.         rjmp    .Lj23
29. .Lj21:
30.         lds     r18,(43)
31.         ldi     r26,127
32.         and     r18,r26
33.         sts     (43),r18
34. .Lj23:

Version: Lazarus 2.3.0 (rev main-2_3-1122-g0a0b688587) FPC 3.3.1 i386-win32-win32/win64

[ccrause]

@dseligo: Try specifying optimization, such as -O1.  The compiler by default generates conservative instructions, which gets optimized by the peephole optimizer.

[avra]

Btw, bithelpers have been added to trunk FPC (sysutils and syshelpers), so now you should also be able to do something like this (not tested on AVR):

Code: Pascal  [Select][+][-]

1. if not PIND.Bits[2] then PORTB.Bits[0] := true else PORTB.Bits[0] := false;

or even better:

Code: Pascal  [Select][+][-]

1. PORTB.Bits[0] := not PIND.Bits[2];