@ Timer

[Paco]

Hello,

at first i have to say that i am german so please forgive me that simple English;)

To my problem:
I do not understand Timer which i can use with the Portcounter. (Yes i had read the manual)

I want to create BREAK which goes 88us, than MAB which goes 8 us and at last a StartBit which takes 4us.



#define BIT_RATE 250000 //rate
#define BIT_TIME XS1_TIMER_HZ / BIT_RATE // So i got 4us BIT_TIME

unsigned count;

oled <: 0 @ count; // The oled Port gets a zero an time gets the portcounter value

//BREAK
count += BIT_TIME*22; //my thought: 4us * 22 = 88us.
oled @ count <: 1;

//MAB
count += BIT_TIME*2; // my thought: 4 us *2 = 8us
oled @ count <: 0;

//STARTBIT
count += BIT_TIME;
oled @ count <: 1;

}

The BREAK works but with the MAB i got my problems. I do not know why but in the waveform its not there, after the BREAK is directly the STARTBIT. What is wrong?


Thanks

Greez Paco

[Folknology]

Maybe your code makes this:

Code: Select all

x___________----_--x

But perhaps you need this:

Code: Select all

x_---------------__--_x

?

[Ross]

Please don't confused timers with port counters.

The latter are 16 bit, timers are 32 bit.

[Paco]

Sorry, my mistake.

I give up trying to mulitplikate the BIT_TIMER instead of that i use a for-loop which works quit good. Only my StopBit which shall be 8us don't work. It seems like its overwritten by the new loop:S? ( BIT_TIME creates a 4 us Time)
Is there Anything i so wrong? Or something i have to know about the Port Counter? In can't find any help for my Problem in the Descriptions on the Page...

I would be glad if someone can help ..

Code: byte = 0b00110101

void seriByte(out port txd, int byte , unsigned time){
int z;
txd <:0 @ time;

for( z=0; z<22; z++){
time += BIT_TIME; //BREAK
txd @ time <: 0;
}
time += BIT_TIME; //MAB
txd @ time<: 1;
time += BIT_TIME; //HOLD
txd @ time<: 1;

time += BIT_TIME; //STARTBIT
txd @ time <: 0;

for (z = 0; z < 8; z++) { //DATA-BITS
time += BIT_TIME;
txd @ time <: >> byte;
}

time += BIT_TIME; //STOPPBITS
txd @ time<: 1;
time += BIT_TIME;
txd @ time<: 1;
}