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Flash Magic Forum

In-System Programming Support => P89C51Rx+/P89C51Rx2/P89C66x/P89C6xX2/P89V66x => Topic started by: shine on August 18, 2005, 04:12:36 AM

Title: about isp and psen
Post by: shine on August 18, 2005, 04:12:36 AM
l can enter isp mode and program the chip successfully when I add the RC at the one PSEN.
but there are more than one chip in my system.if more than one PSEN use the same RC .Flash magic do not work.Who can tell me why ?please
Title: Re: about isp and psen
Post by: erikm on August 18, 2005, 05:19:28 AM
because the other chips which will run activate /PSEN in the normal fashion.

Why not install NoTouch and get rid of the mess.

Erik
Title: Re: about isp and psen
Post by: shine on August 18, 2005, 09:53:15 PM
thank your reply very much .
Maybe to install NoTouch is the best way  .
l just wonder the cause.
PSEN is the output port.
in other words it can not get any logic signal  input
is that right?
Title: Re: about isp and psen
Post by: erikm on August 19, 2005, 05:31:02 AM
l just wonder the cause.

why do you wonder, I already answered

because the other chips which will run activate /PSEN in the normal fashion.
Title: Re: about isp and psen
Post by: erikm on August 19, 2005, 01:59:10 PM
if more than one PSEN use the same RC

bad idea
 
because the other chips which will run activate /PSEN in the normal fashion.

probably you have !psen disabled (AUXR1)on all chips but one.

Erik
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