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assembler macro included in C macro

l.s.,

For delay purposes I need NOP's in an assembler macro, the code below doesn't do the trick. Thread 2267.htm doesn't help me either. A C macroloop, with e.g. DELAY(a); a = 10, slows the execution down too much. Can Anyone help me?

thanks, ***

#define DELAY(a) \
{ \
volatile unsigned b; \
for(b = 0; b < a; b++) \
{ \
} \
}

#define DELAYNOP \
{ \
#pragma asm \
NOP \
NOP \
NOP \
NOP \
NOP \
NOP \
NOP \
#pragma endasm \
}

Parents

0 Bob Horeck over 23 years ago

***,

The simplest form of a delay is:

void Delay (unsigned char Cycles)
{
   // The following generates:
   // C0001: DJNZ R7,C0001   ; 1 to 256 times

   while (--Cycles);
}

If you want to avoid the call use:

#define Delay(Cycles) { while(--Cycles); }

If you need a longer delay modify the function to be:

#include <intrins.h>

void Delay (unsigned char Cycles)
{
   do {
      _nop_();  _nop_(); ...
   } while (--Cycles);
}

Reply

0 Bob Horeck over 23 years ago

***,

The simplest form of a delay is:

void Delay (unsigned char Cycles)
{
   // The following generates:
   // C0001: DJNZ R7,C0001   ; 1 to 256 times

   while (--Cycles);
}

If you want to avoid the call use:

#define Delay(Cycles) { while(--Cycles); }

If you need a longer delay modify the function to be:

#include <intrins.h>

void Delay (unsigned char Cycles)
{
   do {
      _nop_();  _nop_(); ...
   } while (--Cycles);
}

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