A control apparatus and a method for controlling access to a memory in an integrated
circuit for an electronic module is provided. The invention includes a memory which
is split into a plurality of memory areas which contain data relating to the module.
The invention also includes a password register which contains at least one password
for the manufacturer of the module and at least one password for a user. An access
control means stipulates certain conditions for at least one of the memory areas,
such as the extent to which the memory area is readable or writeable, where at
least one of the following conditions can be stipulated for portions of a memory
area: a memory area is readable when the manufacturer password is input; a memory
area is readable when the user password is input; a memory area is readable without
a password; a memory area is writeable when the manufacturer password is input;
a memory area is writeable when the user password is input; a memory area is writeable
without a password. And combinations of the above conditions can be stipulated
according to the setting of lock bits.