topic Assembly Instructions? in S12 / MagniV Microcontrollers

Assembly Instructions?

CIA_MAN275 — Thu, 29 Oct 2020 09:41:21 GMT

Hey Guys!

I need help!

I want an assembly instruction for those c-commands:

 DDRH |= 0x80;

 and

PORTH ^=0x80;

Aim is to switch the light off an on! I am a rookie yes

THX!!

Re: Assembly Instructions?

HSW — Wed, 09 Mar 2011 20:24:03 GMT

There is a S12 opcode for setting a bit in memory:

BSET DDRH #$80

To toggle bit 7 you could implement the following sequence:

LDAA #$80

ADDA PORTH

STAA PORTH

Re: Assembly Instructions?

CIA_MAN275 — Wed, 09 Mar 2011 20:28:05 GMT

I have no S12... so the code don't work!

Re: Assembly Instructions?

CIA_MAN275 — Wed, 09 Mar 2011 20:57:17 GMT

Can you also explain me the following code:

ADDA PORTH

why do you this?

Re: Assembly Instructions?

kef — Wed, 09 Mar 2011 21:25:28 GMT

Why? To be smarter than average, probably :-). ADD isn't faster than EOR, so this trick is as useless as this one

LDAA PORTH ;// PORTH ^= 0x80

SUBA #$80

STAA PORTH

Your successor will like it..., or maybe not

Re: Assembly Instructions?

CIA_MAN275 — Wed, 09 Mar 2011 22:01:57 GMT

When you make -> A= A- $80 than you become the led light off or?

I mean this explanation also above!

THX!!!

Re: Assembly Instructions?

kef — Wed, 09 Mar 2011 22:46:17 GMT

A = A -+ 0x80 will toggle bit7 of A. Will it make LED connected to PORTH on or off I don't know, it depends on initial state of PORTH, also on the circuit.

Re: Assembly Instructions?

CIA_MAN275 — Wed, 09 Mar 2011 22:53:16 GMT

Okay THX!!!!

Here is the whole code:

include <stdio.h>

#include <mc912d128.h>

void delay1ms(void) {
asm("ldy #2666"); //2666 in Y-Register laden
asm("dbne y,."); // Decrement, bis Y=0 ist /
            //3cyc x 125ns x 2666 = 0,99975ms
}

void wait(int duration)
{
while(duration--)
delay1ms();
}

void main(void) {

asm("LDAA #$80");               //DDRH |= 0x80;
asm("STAA $002B");

while(1){
asm("LDAA #$80");           //PORTH ^=0x80;
asm("ADDA $0029");
asm("STAA $0029");
wait(1000);

}

}

Program is ICC12!

THX to all of you for helping hands!

Re: Assembly Instructions?

Lundin — Thu, 10 Mar 2011 21:05:19 GMT

Fundamental Boolean algebra: A + B equals A UNION B equals A OR B