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Use of RRC (Rotate right through carry) in Keil

The 8051 family of microcontrollers has a very useful assembly instruction RRC. This instruction rotates carry into the MSB of the given register, shifts that register right by 1, and carry becomes equal to what used to be the LSB of the register.

  bit NewCarry;
  unsigned char Data;

  NewCarry = Data & 0x01;
  Data = (Data >> 1);
  if (Carry){
    Data = (Data | 0x80);
  }
  Carry = NewCarry;

Basically it does the above, but all in one instruction. I was wondering what the easiest way to include this in my code was. What I want to do is to read a microcontroller pin into carry, shift it into a data byte, and then use the bit that shifts off as an exit condition. Is there an easy way to include a single assembly instruction in Keil? Perhaps a Intrinsic function?

Thanks

-Tom

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0 erik malund over 20 years ago in reply to Oleg Sergeev

would be the ability to compile .asm functions inline

Whaddayamean "would be"? This ability exists.

In a way so clumsy that I agree "this function does not exist"

Erik
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0 erik malund over 20 years ago in reply to Oleg Sergeev

would be the ability to compile .asm functions inline

Whaddayamean "would be"? This ability exists.

In a way so clumsy that I agree "this function does not exist"

Erik
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0 Tom Leys over 20 years ago in reply to erik malund

If I did use CY = Portpin, I would check the compiled assembly for side-affects.

As for the inline assembly compiling thing, I will look into that more.

Thanks for your help everyone !

-Tom
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