Method and device to manage modifications of protected registers in an implantable medical device

An implantable medical device (IMD), comprising:

• a housing enclosing memory, a processor and a protection circuit;
• an electrode combination configured to at least one of i) sense physiologic signals or ii) deliver a therapy:
• memory within the housing to store program instructions in connection with at least one of monitoring physiologic signals or delivering therapy;
• and
• a processor configured to execute the program instructions in connection with detecting physiologic signals along one or more sensing vectors defined by the electrode combination;
• and
• the protection circuit, comprising:
• a bus controller including an address register, and unlock register and a protected register (PR) enable unit, the PR enable unit to set a protect enable signal to an access state based on content loaded into the unlock register;
• and
• a peripheral block including a protected register to retain content for operating the IMD, the peripheral block including a register access input to receive the protected enable signal;
• and
• a PR write control unit to enable an attempted write of the content from a data interface to the protected register when the protected enable signal has an access state.

A method to manage modifications to protected registers within an implantable medical device (IMD), comprising:

• retaining first content in a protected register (PR) for operating the IMD;
• receiving a PR write request representing an attempted write of second content to the protected register;
• analyzing content of an unlock register associated with the protected register;
• setting a protect enable signal to an access state or a deny state based on the content loaded into the unlock register;
• enabling the attempted write of the second content to the protected register when the protected enable signal has the access state.