A method of programming a radiation-hardened integrated circuit includes the
steps
of supplying a prototype device including an SRAM memory circuit or programmable
key circuit to a customer, having the customer develop working data patterns in
the field in the same manner as a reading and writing to a normal RAM memory, having
the customer save the final debugged data pattern, delivering the data pattern
to the factory, loading the customer-developed data pattern into memory, programming
the customer-developed data pattern into a number of production circuits, irradiating
the production circuits at a total dosage of between 300K and 1 Meg RAD to burn
the data pattern into memory, and shipping the irradiated and programmed parts
to the customer.