P89C51RC2 ISP Problem

[Kate]

Hi,

I had a problem programming my code into the microcontroller. And I had check all the condition pin for ISP mode. All condition are met for ISP mode:

P2.6 & P2.7 high
ALE open
PSEN low
reset at falling edge
Vdd & Vcc high
Vss Gnd
TX and Rx connected

I had try to load the programming code with both WINISP and Flash Magic.  Still connection is not made. How should I shart to debug my board??

[erikm]

How should I shart to debug my board??
If a fresh from factory chip will not program it will be either
PC to MAX232(equivalent)
MAX232 to UART
oscillator not running
or reset (you are not using RC are you?)

When a chip has not 'seen' any programming it IS in ISP mode.  For the convenience of volume users the chips are shipped "ISP ready"

Erik

[Kate]

No, I am not using RC, instead i'm using chip crystal...

[S.Nandu]

Hi ,
Am also new to this grp,infact i have also faced several problems with p89c51rd2hbp,but was resolved by deliberate analysis and testing.Now am using p89c51rd2bn which is the recent micro available in the marke. As per the errata i did the modification ,still the controller is not entering the ISP mode.I changed the C and R value for 5V Vpp ,still the user code is executed.How can i rectify this issue???
Is anybdy facing this same problem with rd2BN micro???
Plz mention if you have any concerns on this.

Regards,
Nandu.S

[Annibal Abreu]

Hi

You need to read AN461 and NOTOUCH from ERIK.

[Annibal Abreu]

AN 461:

http://www.semiconductors.philips.com/acrobat/applicationnotes/AN461_8.pdf

NOTOUCH
http://www.8052.com/users/erikm/notouch.doc

http://www.8052.com/users/erikm/backdoor.doc