With Designer tools, you can use the silicon signature to identify and track Actel designs and devices. When you generate a programming file, you can specify a unique silicon signature to program into the device. This signature is stored in the design database and in the programming file, and programmed into the device during programming.
The silicon signature is accessible through the USERCODE JTAG instruction.
NOTE: If you set the security level to high, medium, or custom,
you must program the silicon signature along with the Security Setting.
If you have already programmed the Security Setting into the target device,
you cannot reprogram the silicon signature without reprogramming the Security
Setting.
The previously programmed silicon signature will be erased if:
You have already programmed the silicon signature and
You are programming the security settings, but you do not have an entry in the silicon signature field