Inline asembler

[SamY Fareast]

Hi all
I'm just working with dspic30f3012 on FRC x8 clock.

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asm
  BTG LATC,  13
end

This code not work.

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asm
  MOV #$2000 , W0
  XOR LATC

Also this.
But

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asm
  MOV #$2000 , W0
  XOR LATC, WREG

This code work fine. But I feel something funny.
MicroChips saying on DS70157B PAGE3-5 that

When the optional {,WREG} operand is specified, the destination of the instruction is
WREG. When {,WREG} is not specified, the destination of the instruction is the file
register f.

Could anyone helps me?

[milan]

Hi,

you should check several things to locate the problem:
1) are asm instructions used in proper format
2) is compiler excepting asm instructions properly and
are they transformed to correct opcode (this is our job, there should be
no errors, we tested lot of code)
3) is there another problem (MCU, datasheet ...)

I tried this code on RC13 and it's not working:

Code: Select all

program test;
begin
  ADPCFG := 0xFFFF;
  
  TRISB := $0000;
  TRISC := $0000;

  PORTC := 0xFFFF;
  asm
    BTG LATC,  13
  end;
end.

But the same code is working on RB3 pin:

Code: Select all

program test;
begin
  ADPCFG := 0xFFFF;
  
  TRISB := $0000;
  TRISC := $0000;

  PORTB := 0xFFFF;
  asm
    BTG LATB,  3
  end;
end.

So, it is probably something with RC13 pin.
See the other functions of RC13 in the Datasheet and configure RC13 as I/O pin (if possible).

[yo2lio]

Hello Milan,

No, it's compiler problem :

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;test_DSPIC.dpas,10 :: 		BTG W11, #13
$0116	$A2D00B			BTG	W11, #13
;test_DSPIC.dpas,11 :: 		BTG LATB, 13
$0118	$AABFFF			BTG	LATB, 13

This ASM code not exist :

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BTG	LATB, 13

must be :

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BTG	LATB, #13

and compiler give error : 0:11 E-420 Invalid ASM instruction (51): LATB (0x000118) #13

From datasheet :

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BTG f,#bit4 Bit Toggle f 
BTG Ws,#bit4 Bit Toggle Ws

I'm sure that this problems will be resolved in new PRO Compiler for DSPIC.

[SamY Fareast]

milan:

But the same code is working on RB3 pin:

Code: Select all

program test;
begin
  ADPCFG := 0xFFFF;
 
  TRISB := $0000;
  TRISC := $0000;

  PORTB := 0xFFFF;
  asm
    BTG LATB,  3
  end;
end.

Now I tested the code, on software debugger, but it works still funny.
After set PORTB tp $FFFF, LATB still $0000, and after BTG instruction so on.

YES, I know kind of this try will mix up compiler issue and debugger issue,
So i will try it on real chip later.
And I have a question, if you set PORTB to $0000( instead $FFFF), did your code still work fine?

yo1lio:

must be :

Code: Select all

BTG   LATB, #13

and compiler give error : 0:11 E-420 Invalid ASM instruction (51): LATB (0x000118) #13

I don't know why, but on

instruction f, #13

style code, MP's inline asembler gives this error.
ie.

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 BCLR LATC, #13

but

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 BCLR LATC, 13

works fine.

[FRM]

I'm sure that this problems will be resolved in new PRO Compiler for DSPIC.

Hi Florin, sorry to be slightly off-topic, but where can I read more about this new version

[milan]

Hi,

This ASM code not exist :

Code: Select all

BTG	LATB, 13

must be :

Code: Select all

BTG	LATB, #13

Yes, you are right. We will correct this for the next compiler release.
Thank you for the other post too (DSPIC, BTSC f,#bit4 error).

@ SamY fareast
I can't check it on HW right now, I will try the code soon.

[milan]

Hi,

I think I found a problem.
Try this code:

Code: Select all

program test;
begin
  ADPCFG := 0xFFFF;

  TRISB := $0000;

  // RB11
  LATB := 0xFFFF;  Delay_ms(1000);
  asm
    BTG LATB,  11
  end;             Delay_ms(1000);

  LATB := 0;       Delay_ms(1000);
  asm
    BTG LATB,  11
  end;             Delay_ms(1000);
  
  // RB3
  LATB := 0xFFFF;  Delay_ms(1000);
  asm
    BTG LATB,  3
  end;             Delay_ms(1000);

  LATB := 0;       Delay_ms(1000);
  asm
    BTG LATB,  3
  end;             Delay_ms(1000);
  
end.

Code generator somehow produces the same BTG opcode $AA62CA for RB3 and RB11.

We will investigate/fix this, I am sorry for the trouble we caused.

I tested the code on 30F4013 because it has RB11 pin.

Workaround: for pins 8,9,... use if then. This code work ok on 30F4013:

Code: Select all

program test;
begin
  ADPCFG := 0xFFFF;

  TRISB := $0000;

  // RB11
  LATB := 0xFFFF;  Delay_ms(1000);
  if LATB.11 > 0 then
    LATB.11 := 0
  else
    LATB.11 := 1;  Delay_ms(1000);

  LATB := 0;       Delay_ms(1000);
  if LATB.11 > 0 then
    LATB.11 := 0
  else
    LATB.11 := 1;  Delay_ms(1000);

  // RB3
  LATB := 0xFFFF;  Delay_ms(1000);
  asm
    BTG LATB,  3
  end;             Delay_ms(1000);

  LATB := 0;       Delay_ms(1000);
  asm
    BTG LATB,  3
  end;             Delay_ms(1000);

end.

[yo2lio]

I suggest to use this code :

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  LATB := LATB;
  asm
    MOV #0x8000, W0   // toggle bit 15
    XOR LATB

    MOV #0x2000, W0   // toggle bit 13
    XOR LATB

    MOV #0x0800, W0   // toggle bit 11
    XOR LATB

    MOV #0x0080, W0   // toggle bit 7
    XOR LATB
  end;

[SamY Fareast]

Hi milan

I think I found a problem.
Try this code:

I tried that code on 30F4012.
As you said, RB3 blinked on EasydsPIC4 board.
But on software-simulator, LATB become $0008 at first BTG instruction.
So, I think there is another bug(s?) on simulator.

yo2lio:
Thank you for your suggestion.
On first post, I also wrote about odd behaver of XOR LATC {WREG}.
but now I cant remember that happened on real chip or on simulator.
So I will try it next weekend.

[yo2lio]

You must initialize the register first :

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LATC := LATC;
asm
  MOV #$2000 , W0
  XOR LATC 
end;

Now must work !

[SamY Fareast]

Hi, yo2lio

You must initialize the register first :

No, LATC is one of predefined globals, so there is no need to assign initial value.

I tried this code, on 10MHz XT DSPIC30F4013 on EASYdsPIC4 board.

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program TestAsm;
begin
  ADPCFG := 0xFFFF;
  TRISB := $0000;
  TRISC := $0000;
  LATC := $A000;
  LATB := $AAAA;
  Delay_ms(1000);
  while true do begin
    asm
      MOV #$FFFF,W0
      XOR LATB
      XOR LATC
    end;
    Delay_ms(1000);
  end;
end.

I think LEDs on boards should blink, but not.
Next I tried this code

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program TestAsm;
begin
  ADPCFG := 0xFFFF;
  TRISB := $0000;
  TRISC := $0000;
  LATC := $A000;
  LATB := $AAAA;
  Delay_ms(1000);
  while true do begin
    asm
      MOV #$FFFF,W0
      XOR LATB, WREG
      XOR LATC, WREG
    end;
    Delay_ms(1000);
  end;
end.

LEDs should not blink, only value of WREG should toggled, but LEDS blink.
I can't find variable 'WREG' in p30F4013.dpas, but I can compile above code.

[SamY Fareast]

Oh, I am sorry, I was wrong. yo2lio
I tested this code.

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program TestAsm;
begin
  ADPCFG := 0xFFFF;
  TRISB := $0000;
  LATB := LATB;
  while true do begin
    asm
      MOV #$FFFF,W0
      XOR LATB, WREG
    end;
  end;
end.

MP generated this. (TestAsm.asm)

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;TestAsm.dpas,9 :: 		XOR LATB, WREG
$0110	$B6A2CA			XOR	LATB, WREG

Then i commented out 'LATB := LATB".
Still I could compile without any errors. But MP generated this

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;TestAsm.dpas,9 :: 		XOR LATB, WREG
$0110	$B6BFFF			XOR	LATB, WREG

Linker may lost LATB. and write to $1FFF.

And finally I compile this.

Code: Select all

program TestAsm;
begin
  ADPCFG := 0xFFFF;
  TRISB := $0000;
  LATB := LATB;
  while true do begin
    asm
      MOV #$FFFF,W0
      XOR LATB
    end;
  end;
end.

MP. generates this

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$0110	$B682CA			XOR	LATB

$82 is %10000010. This means distnation is WREG.
So it reverses.

[milan]

Hi,

this problem is solved

Code: Select all

program test;
begin
  ADPCFG := 0xFFFF;
  TRISB := $0000;
  
  while TRUE do
    begin
      asm
        BTG LATB,  #11
        BTG LATB,  #3
      end;
    end;
end.

tested on hardware

Solution will be included in the next release (beta version is very near now).

Thank you for your help and patience.

Check announcements on forum,
test codes from this topic with beta
and report us if something is not solved.