When would a 8051 halt/hang ?

[Integrated]

8051 halt situations

Hi all.

I have developed an at89c51 based board. but this micro halts right after the poweron.

At all, what are the situations , 8051 halts (hangs ) in?

(Philips supporter says , this is due to supply noise , but i have no noise on my supply line. my board sinks max 1.2 A , from a regulator 7805)

thanx a lot and regards.

 

[SphinX]

8051 halt situations

Hi,

It's better to add a decoupling capacitor (100 nF)between the VCC and GND of all the ICs include 89C51.