Apple Inc.

Mitchell Palmer Lichtenberg, Jr

Deniz Balkan

Kevin R Walker

Manu Gulati

James D Ramsay

An integrated circuit (IC) having a bridge for interfacing a debugger and method of operating the same is provided. In one embodiment, an IC includes a debug control circuit and a debug interface block (DIB) implemented thereon. The DIB is coupled to the debug control circuit. The IC also includes an interface for a debugger and a number of interfaces for external circuits, each of the interfaces being coupled to the debug control circuit. The debug control circuit may function as a bridge for coupling an external debugger to the DIB and to external circuits coupled to the IC through corresponding ones of the interfaces. The debug control circuit may establish a connection between the debugger and one of the external circuits. Communications between the debugger and the external circuit may be conducted while bypassing the DIB.

Serial wire debug bridge

A debug port configured to generate and provide a return clock is disclosed. In one embodiment, an integrated circuit (IC) includes one or more functional units and a debug port (DP). The DP is configured to enable access by an external debugger to the functional unit(s) of the IC for debugging purposes. The DP includes circuitry that may generate a first clock signal that is provided to the functional unit(s) during debug operations. Receiving test result data at the DP may require a return clock signal that is not provided by the functional unit(s). Accordingly, the IC may include a clock modifier coupled to receive the first clock signal. The clock modifier may generate a second clock signal based on the first, the second clock signal being provided to the DP as a return clock signal.

Debug access with programmable return clock

A method and apparatus of stopping a functional block of an integrated circuit (IC) for debugging purposes is disclosed. In one embodiment, an IC includes a number of functional units accessible by an external debugger via a debug port (DP). During a debug operation, a power controller in the IC may power down a functional unit. When the functional unit is powered off, a first register may be programmed. Responsive to the programming of the first register, a first signal may be asserted and provided to the functional unit. When power is restored to the functional unit, operation of the functional unit may be halted prior to execution of instructions or other operations, responsive to the signal.

Growing community of inventors

Sunnyvale, CA, United States of America

Mitchell Palmer Lichtenberg, Jr