Changing chip function based on fuse states
View Patent ↗Techniques and systems whereby operation of and/or access to particular features of an electronic device may be controlled after the device has left the control of the manufacturer are provided. The operation and/or access may be provided based on values stored in non-volatile storage elements, such as electrically programmable fuses (eFUSES).
1. A method for controlling access to specific modules of an integrated circuit device, comprising:
setting a device state for the integrated circuit device in an electrically programmable fuse bank comprising a plurality of electrically programmable fuses;
reading the device state from the electrically programmable fuse bank with a device controller; and
disabling modules of the integrated circuit device in accordance with the device state read by the device controller, wherein disabling modules comprises placing the device in a dead device state by at least one of turning off a clock signal to a module, disabling a multiplexer select associated with a module, or disabling an I/O line of the module.
2. The method of claim 1 , wherein setting a device state comprises blowing a sequence of electrically programmable fuses in the electrically programmable fuse bank to generate a unique device state identifier.
3. The method of claim 2 , wherein reading the device state comprises reading the unique device state identifier upon startup of the device and configuring the device in accordance with the unique device state identifier.
4. The method of claim 2 , wherein the unique device state comprises at least one of a test state, a shipped state, and a functional state.
5. The method of claim 1 , wherein disabling modules comprises rendering the modules inaccessible to external components.
6. A method for controlling access to specific modules of an integrated circuit device, comprising:
setting a device state for the integrated circuit device in an electrically programmable fuse bank comprising a plurality of electrically programmable fuses:
reading the device state from the electrically programmable fuse bank with a device controller; and
disabling modules of the integrated circuit device in accordance with the device state read by the device controller, wherein,
setting a device state comprises blowing a sequence of electrically programmable fuses in the electrically programmable fuse bank to generate a unique device state identifier,
the unique device state comprises at least one of a test state, a shipped state, and a functional state, and
the test state comprises a device configuration where all device registers are accessible through a device interface, the shipped state comprises a device configuration wherein selected device registers containing proprietary information are not accessible through the interface, and wherein the functional state comprises a device configuration where all registers not intended to be accessible to an end user of the device are not accessible through the interface.
7. A method of controlling access to features of an electronic device, comprising:
providing a bank of electrically programmable fuses on the electronic device;
shipping the electronic device in a product with a first set of features enabled;
after shipping the product, enabling an additional feature not included in the first set of features by programming one or more of the bank of electrically programmable fuses;
receiving, from a user, a request to enable the additional feature; and
enabling the additional feature in response to receiving a payment from the user for the additional feature.
8. The method of claim 7 , wherein:
the request and payment are received from the user via the Internet; and
the additional feature is enabled by programming one or more of the bank of electrically programmable fuses, wherein the programming is initiated via the Internet.
9. A method for disabling one or more features of an integrated circuit device, comprising:
detecting an event; and
in response to detecting the event, applying one or more high voltage spikes to field effect transistors (FETs) of circuits utilized to implement the one or more features, wherein the particular FETs to which the high voltage spikes are applied are determined by values stored in a bank of non-volatile storage elements.
10. The method of claim 9 , wherein the event comprises at least one of:
removal of a system component; or
nonexistence of the system component.
11. The method of claim 9 , further comprising:
setting a non-volatile latch in response to detecting the event; and
upon a subsequent power-on sequence, applying the one or more high voltage spikes to the field effect transistors (FETs) in response to detecting the non-volatile latch is set.