89C51 dotaz

Středa Březen 17 12:02:50 CET 2004

Ten procesor ma vsechny porty po resetu nastavene na log.1, cili na vysokou
impedanci.

V programataru se samozrejme tato vec neresi, nemuzete prece spustit
program, ktery nastavi porty do vysoke impedance, kdyz tam v tom procesoru
zadnej program neni, ze.

Jirka

----- Original Message -----
From: Jozef Maslík <jozefmaslik@nextra.sk>
To: Multiple recipients of list <hw-news@list.gin.cz>
Sent: Thursday, May 03, 2001 11:01 PM
Subject: Re: 89C51 dotaz

> Port 0 je z tranzistorou s otvorenym kolektorom, ak teda chces mat
> vysokoimpedancny vstup, treba programom zapisat na port0 log 1 (uroven H).
>
> ----- Original Message -----
> From: "Joe" <waking@centrum.cz>
> To: "Multiple recipients of list" <hw-news@list.gin.cz>
> Sent: Thursday, May 03, 2001 10:02 PM
> Subject: 89C51 dotaz
>
>
> > This is a multi-part message in MIME format.
> >
> > ------=_NextPart_000_002A_01C0D41C.4626E1E0
> > Content-Type: text/plain;
> > charset="iso-8859-2"
> > Content-Transfer-Encoding: quoted-printable
> >
> > Delam si programator 51 a potreboval byvh od vas poradit s jednou =
> > zalezitosti, od atmelu jsem si stahl popis a pisou tam ze pokud   port 0
=
> > nastavim do H urovne, pak slouzi tento port jako vysoko ohmovy vstup, =
> > ale nevim, jestli ho mam nastavit programove, ci pripojit p0 na H.
> > diky joe
> >
> > ------=_NextPart_000_002A_01C0D41C.4626E1E0
> > Content-Type: text/html;
> > charset="iso-8859-2"
> > Content-Transfer-Encoding: quoted-printable
> >
> > <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
> > <HTML><HEAD>
> > <META content=3D"text/html; charset=3Diso-8859-2" =
> > http-equiv=3DContent-Type>
> > <META content=3D"MSHTML 5.00.2614.3500" name=3DGENERATOR>
> > <STYLE></STYLE>
> > </HEAD>
> > <BODY bgColor=3D#ffffff>
> > <DIV><FONT face=3D"Arial CE" size=3D2>Delam si programator 51 a =
> > potreboval byvh od=20
> > vas poradit s jednou zalezitosti, od atmelu jsem si stahl popis a pisou
=
> > tam ze=20
> > pokud&nbsp;&nbsp; port 0 nastavim do H urovne, pak slouzi tento port =
> > jako vysoko=20
> > ohmovy vstup, ale nevim, jestli ho mam nastavit programove, ci pripojit
=
> > p0 na=20
> > H.</FONT></DIV>
> > <DIV><FONT face=3D"Arial CE" size=3D2>diky =
> > joe</FONT></DIV></BODY></HTML>
> >
> > ------=_NextPart_000_002A_01C0D41C.4626E1E0--
> >
>