AT89S52 signature detected but AT89LP52 fails

Started by mik3ca 1 week ago1 replylatest reply 1 week ago12 views

This week my local supplier ordered some AT89LP52's for me and I bought them today and they all arrived in a plastic anti-static package which makes me think they can work.

I made myself a program in software as well as hardware that successfully programs AT89S52's every time. I read the manual for the AT89LP52 and compared it with AT89S52, and both claim that reading signature byte address 0 should return 1Eh. For the AT89S52, this is true. However, for the AT89LP52, 1Eh is never returned.

I also see in the AT89LP52 manual that there is a bit to represent "half page". Why?

All I want to do is program this like I can program the AT89S52 but I want processing speed to be better.

Remember. I'm doing the exact same procedure to attempt to get the first byte of the atmel signature byte for both chips. and I am issuing the program enable command as well (otherwise I wouldn't be able to get the AT89S52 working)

Is there something I or the manual is missing that I need to know?

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Reply by mik3caJanuary 8, 2019

It turns out that I am an owner of one counterfeit chip. This is because I tried another one from the same package and that one works well.