Integrated circuit with asymmetric access privileges

1. An integrated circuit configured to drive an audio transducer, the integrated circuit comprising:

first and second interfaces; and

an internal addressable space comprising a plurality of address ranges;

wherein the integrated circuit stores an access permission to define an authorized subset of address ranges to which access by an external processor is permitted during runtime control of the integrated circuit;

wherein each of the first and second interfaces is coupled to the internal addressable space, and wherein each of the first and second interfaces is configured to receive a request, from the external processor, to access at least one of the address ranges of the internal addressable space; and

wherein the integrated circuit is configurable in a first state in which the external processor is permitted, via the first interface, access to the authorized subset of address ranges and is prevented, via the first interface, access to the remainder of the address ranges during runtime control of the integrated circuit and the external processor is permitted, via the second interface, access to the plurality of address ranges, and configurable in a second state in which the external processor is permitted, via the second interface, access to the authorized subset of address ranges and is prevented, via the second interface, access to the remainder of the address ranges during runtime control of the integrated circuit and the external processor is permitted, via the first interface, access to the plurality of address ranges.

2. The integrated circuit of claim 1 , wherein the configuration of the integrated circuit is set via the first interface.

3. The integrated circuit of claim 1 , further comprising comprises a first gate and a second gate, each gate having an ON state and an OFF state, wherein each interface is coupled to the internal addressable space via a respective gate, and wherein the integrated circuit being the first state corresponds to the first gate being in the ON state and the second gate being in the OFF state, and the integrated circuit being configured in the second state corresponds to the second gate being in the ON state and the first gate being in the OFF state.

4. The integrated circuit of claim 1 , further comprising a policy table, wherein the policy table stores an access permission defining the authorized subset of address ranges to which access by the external processor is permitted during runtime control of the integrated circuit.

5. The integrated circuit of claim 3 , further comprising a policy table storing the access permission defining the authorized subset of address ranges to which access by the external processor is permitted during runtime control of the integrated circuit, wherein each gate is coupled to the policy table, and wherein, in the ON state, each gate is configured to allow access via its respective interface to the internal addressable space according to the policy table.

6. The integrated circuit of claim 3 , further comprising an audit module configured to, for an incoming request received via the first or second interface, access at least one address of the plurality of address ranges, access the policy table to determine an access permission associated with the at least one address, and to transmit a signal to the respective gate, wherein the gate, in the ON state, is configured to, on receipt of the signal from the audit module, adopt a configuration according to which the received access request is allowed or denied depending on the access permission associated with the at least one address.

7. The integrated circuit of claim 3 , wherein the ON/OFF state of each gate is configured to be set via non-volatile memory.

8. The integrated circuit of claim 7 , wherein the non-volatile memory comprises one-time-programmable (OTP) memory.

9. The integrated circuit of claim 6 , wherein the audit module comprises a comparator.

10. The integrated circuit of claim 6 , wherein the incoming access request received via the first or second interface comprises a request to read, write, or read and write the at least one address and wherein the associated access permission comprises a permission to read, write, or read and write the at least one address.

11. The integrated circuit of claim 1 , wherein the access permission is configured to be set via one of the first and second interfaces.

12. The integrated circuit of claim 1 , wherein the integrated circuit is configured such that, following boot of the integrated circuit, modification of the access permission is prevented.

13. The integrated circuit of claim 1 , configured in the first or second state.

14. The integrated circuit of claim 1 , comprising a plurality of interfaces, wherein each one of the plurality of interfaces is coupled to the internal addressable space, and wherein the integrated circuit is configurable in a state in which the integrated circuit is configurable in a state in which the external processor is permitted, via at least one of the plurality of interfaces, access to the authorized subset of address ranges and is prevented, via the at least one interface, access to the remainder of the address ranges during runtime control of the integrated circuit and the external processor is permitted, via at least another one of the plurality of interfaces, access to the plurality of address ranges.

15. The integrated circuit of claim 14 , wherein the configuration of the integrated circuit is set via the first interface.

16. A system comprising the integrated circuit of claim 1 , the system comprising:

a secure microcontroller coupled to the addressable space via one of the first and second interfaces; and

a processor coupled to the addressable space via the other of the first and second interfaces.

17. The system of claim 16 , wherein the processor is configured to initialize an operating system, and wherein the secure microcontroller is configured to initialize the integrated circuit prior to the completion of the processor initializing the operating system.

18. The system of claim 16 , wherein the processor is configured to trigger the secure microcontroller to initialize the integrated circuit.

19. An integrated circuit configured to drive an audio transducer, the integrated circuit comprising:

first and second interfaces; and

an internal addressable space comprising a plurality of address ranges;

wherein the integrated circuit stores an access permission to define an authorized subset of address ranges to which access by an external processor is permitted during runtime control of the integrated circuit,

wherein each of the first and second interfaces is coupled to the internal addressable space and wherein each of the first and second interfaces is configured to receive a request, from the external processor, to access at least one of the address ranges of the internal addressable space,

wherein the integrated circuit is configured to allow the external processor, via the first interface, access to the authorized subset of address ranges, and to deny the external processor, via the first interface, access to the remainder of the address ranges, during runtime control of the integrated circuit, and to allow the external processor, via the second interface, access to the plurality of address ranges.

20. The integrated circuit of claim 19 , further comprising a gate, wherein the first interface is coupled to the internal addressable space via the gate, and wherein the gate is configured to allow access via the first interface to the internal addressable space according to the policy table.

21. The integrated circuit of claim 20 , further comprising an audit module configured to, for an incoming request received via the first interface, access at least one address of the plurality of address ranges, determine an access permission associated with the at least one address, and to transmit a signal to the gate.