Yesterday I found out that 2 of 6 ATTiny2313 I have are not programmable. They report random (!) bytes when I am trying to read configuration bytes. Most often they return FF00FF and 00FF00, but almost any combination could be there.
All devices are from the same batch. Any possibilities that the problem is in a programmer are almost improbable, I have 2 programmer devices and both are returning the same result.
Did anybody else ever run into this trouble ?