Memory protection

A method of controlling memory access on an integrated-circuit device comprising a processor and memory for storing executable code, the method comprising:

• determining the state of a read protection flag for a protected region of the memory;
• detecting a memory read request by the processor;
• determining whether the read request is for an address in the protected region of the memory;
• determining whether the processor issued the read request while executing code stored in the protected region of the memory;
• and
• denying read requests for addresses in the protected region if the read protection flag for the protected region is set, unless at least one of one or more access conditions is met, wherein one of said access conditions is that the processor issued the read requests while executing code stored in the protected region.

An integrated-circuit device comprising a processor, non-volatile memory, non-volatile memory control logic, and memory protection logic, wherein:

• the memory protection logic is arranged to control access to a protectable region of the non-volatile memory in dependence on protection configuration data stored in a protection-configuration region of the non-volatile memory;
• the non-volatile memory control logic is arranged to prevent writing to any portion of the protection-configuration region unless that portion is in an erased state;
• and
• the non-volatile memory control logic is arranged to allow the protection-configuration region to be erased only if the protectable region is in an erased state.

A method of controlling memory access on an integrated-circuit device comprising a processor and non-volatile memory, the method comprising:

• controlling access to a protectable region of the non-volatile memory in dependence on protection configuration data stored in a protection-configuration region of the non-volatile memory;
• preventing writing to any portion of the protection-configuration region unless that portion is in an erased state;
• and
• allowing the protection-configuration region to be erased only when the protectable region is in an erased state.