is locked 8051 copy protected

There is no such thing as 100% secure, but there are some general rules : Newer devices are generally better than old ones, and ones with inbuilt brownout detectors will be better than ones that can be run 'outside spec'. eg Look at the AT89C51RD2/ED2 - probably better for new designs than the 89C55 (89C55WD)

Some 51's also use an Encryption array, which applys that multibyte XOR pattern to any verify read. You need to make unused code areas other than FF FF FF FF, and there is more admin, but it does raise the security level. -jg

In article , michael K. writes

Most 8051 flash parts have security bits. If you set these when you program it they are secure. It depends how much some one is going to want to attack your system

Many 51's have 16/32 K flash. what other peripherals do you need? I assume it is a single chip system?

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ \/\/\/\/\ Chris Hills Staffs England /\/\/\/\/\ /\/\/ snipped-for-privacy@phaedsys.org

thanks for your answers.

I need the peripherals a 8052 contains . I think there must be power supply glitch method with which somebody can decode the protected code . Is anybody familiar with that ?

In article , Kefalas Mihalis writes

There is for the Atmel 89C51/52 device, I have been on the wrong end of such a hack, but I don't intend to post the details here, just be aware that it is possible to unlock them.

I do not know if the recently released 89S52, with which Atmel are replacing the 89C52, is any more secure.

Have a look at .

I'd still once think about not worrying about copy protection. A sufficiently determined and well funded opponent will break it anyway.

Tauno Voipio tauno voipio @ iki fi

If you want real security, have a look at some of Maxim's offerings. They have code encryption and even intrusion detection/self destruct to stop direct manipulation. Just search on their site for 'secure microcontroller'.

Cheers, FoxyRick.