pic16f628a code protect off
Thanks my friends, i have finally concluded that when you set a code protection bit, you protect the area of memory (program and/or data, depending wheter you set the appropriate bits in the configuration word), in such a way that, when you try to read the program memory or data memory, you receive 0x0000 or 0x00 respectively. This protect someone else from stealing your code. however, if you run the bulk erase program memory command, you erase both of areas(data and program) and reset the configuration word to 0x3FFF, so that you can program again the pic, but you cannot see the code that was previously burned.
Someone told me that its possible to "hack" the pic (i think that has something to do with manipulating the power pins), and they can do reverse engineering, disabling those protection bits and then read the code.
I have found that some models have a special function called chip erase, that do what i mentioned above, and because pic16f628, doesnt had this function i was wondering that this old model would not clear after the protected bits were set. This is what was confusing me. Thanks everybody for the help.