Direct Port Manipulation

[jackberg]

Hello everyone,

this is a very simple question, how to send a 1 or 0 to a 08m2 chip faster than HIGH C.1 : LOW C.1

I'm looking to send a pulse of 400ns ~ 1000ns, can a 08m2 at 32Mhz is able to do this.

Thanks to all

 

[Engle]

I think the best you'd get is the pulsout command in Manual 2 (1.25us at 32MHz). If that's not quick enough then I guess it's external electronics.

 

[jackberg]

Thanks Engle
I did tested a MM74C221 to get this timing, and looking with a 08m2 if it's possible.

 

[jackberg]

There's no direct port manipulation in Picaxe like arduino ?

 

[AllyCat]

Hi,

.... how to send a 1 or 0 to a 08m2 chip faster than HIGH C.1 : LOW C.1

Do you mean transmit a (<1 us) pulse FROM an 08M2 ?

It depends if you need to control the width of the pulse and if it can be repetitive. A PWM output can be as low as 250 ns with SETFREQ M4, but the pulse will repeat about every 250 us. You might be able to gate that with the on-chip DSM and another PWM or perhaps software commands. Another possibility might be to setup a HSEROUT command sending just a "Start" pulse at something over 1M baud !

Cheers, Alan.

 

[jackberg]

Hi AllyCat,
it's not for a PWM pulse, it's for a single signal, to read/write enable to an EEPROM

 

[jackberg]

the datasheet refer a signal between 300ns ~ 1000ns