P89C662HBA trouble

[a9o1o8o]

 OK,if I  set  security bit1 or set security bit2 or set security bit3(May be set all three security bit )when download my code to P89C662HBA,Does it will cause I can't  Handshake to MCU successuflly next time？Who can help me？

[a9o1o8o]

I mean that just cant't read chip's Identity number or BOOT VECTOR or STATUS BYTE's value? if I set security bit

[Andy Ayre]

The functionality of each bit is described in the P89C662 data sheet from NXP. Only set the security bits if you are sure what they do.

Andy

[a9o1o8o]

You mean that I cant't read chip's Identity number or BOOT VECTOR or STATUS BYTE's value?

[Andy Ayre]

Look at table 16 in the data sheet. It tells you exactly what each bit does. It looks to me like yes, you should still be able to use ISP and still be able to read the signature, boot vector and status byte.

A full chip erase will erase all the security bits.

Andy

[a9o1o8o]

Can I erase the full chip through ISP this way?

[Andy Ayre]

According to the data sheet, yes.