Question about GAL16V8 Problem

[talrek]

Hi,
i have problems with some GAL16V8.

I have GAL16V8B and GAL16V8D
When i program 16V8B, the sequence erase, program, verify and encrypt. After that when i do a verify, it is Ok, and if i read the GAL content it is the same as the original file.

Problem is my GAL16V8D, if i do the same sequence all is ok; but after verifying is KO and the content of the GAL after reading is almost empty (lot of 1111...)

I i remove encryption step, i'm able to read the content and verify is Ok.

So where is the problem ? Encryption or GAL16V8D which don't allow encryption ?

Also, finally if i want to use the gals on a device, must it be encrypted to work ?

Thank you all for the clearings.

[gerald]

I've not played with GAL for ... 20 years 
But like the encryption word may hint, it's here to prevent device configuration read back (ie IP protection).
I would guess that GAL16V8B does not support encryption and you can always read it.
GAL16V8D is supporting encryption, and you cannot read it back if set.

now it's up to you to set the encryption or not, but it should change the functionality