Abstract: A processor unit includes a memory and an ALU coupled with the memory. The processor unit also comprises a test controller, a test control register, and a signature register. The test controller manages a series of steps to test the processor unit. It overrides an ALU control signal with a replacement ALU control signal, stored in the test control register. It generates a test pattern and writes it to a memory address. It reads memory output data from the memory address, and forwards it to the ALU. The ALU executes an operation on the memory output data based on the replacement ALU control signal. The ALU output provides a test result, which is compressed to obtain a test signature, and stored in the signature register.

Abstract: An IC includes an array of processor units, arranged in two or more subarrays. A subarray has a test generator, a multiplexer to apply a test vector to a datapath, and a test result output. It includes one or more processor units. A test result compressor is coupled with an output of the datapath, and compresses output data to obtain a test signature, which it stores in a signature register. The signature register is legible from outside the subarray. The datapath includes one or more memories and one or more ALUs. Test data travels through the full datapath, including the memories and the ALUs. ALU control registers are overridden during test to ensure a testable datapath.

Abstract: Methods and apparatuses are disclosed for testing multicore processors. In some embodiments, the tested multicore processor may include at least a first core and a second core, a data input coupled to a first scan chain in the first core and a second scan chain in the second core, and a multiplexer including at least a first input and a second input, the first input coupled with a data output of the first scan chain and the second input coupled with a data output of the second scan chain, the multiplexer further including an output that couples to one or more pins on a package of the processor, the multiplexer further including a select signal that couples to the one or more pins on the package of the processor, and wherein the data input couples to the one or more pins on the package of the processor.

Abstract: Methods and apparatuses are disclosed for testing multicore processors. In some embodiments, the tested multicore processor may include at least a first core and a second core, a data input coupled to a first scan chain in the first core and a second scan chain in the second core, and a multiplexer including at least a first input and a second input, the first input coupled with a data output of the first scan chain and the second input coupled with a data output of the second scan chain, the multiplexer further including an output that couples to one or more pins on a package of the processor, the multiplexer further including a select signal that couples to the one or more pins on the package of the processor, and wherein the data input couples to the one or more pins on the package of the processor.

Abstract: Systems and methods for enabling on-chip features via efuses. A system comprises an electronic fuse (Efuse) array (EFA) coupled to each features capability register (FCR) within an instantiated computational block. The EFA comprises a plurality of rows wherein programming an row comprises blowing one or more Efuses of the row. A valid row comprises programmed Efuses corresponding to one or more on-chip enabled features. The EFA is further configured to prevent enabling of disabled on-chip features from occurring subsequent to a predetermined point in time, such as the time of shipping the chip to the field for use by end-users, by establishing a particular default state for electronic fuses and rendering unusable any unprogrammed entries of the EFA. In one embodiment, some features correspond to on-chip hardware cryptographic acceleration.

Abstract: An integrated circuit including embedded test functionality. An integrated circuit may include a plurality of processor cores each configured to execute instructions, and a test access port configured to interface circuits included within the integrated circuit with a test environment external to the integrated circuit for testing of the circuits. The test access port may include virtualization logic configured to allow a first set of instructions executing on the given processor core to control activity of the test access port for testing of the circuits. In one embodiment, the circuits may be accessible for testing via a plurality of scan chains, wherein the scan chains and the test access port are compliant with a version of Joint Test Access Group (JTAG) standard IEEE 1149, and wherein the test access port includes a Test Data In (TDI) pin, a Test Data Out (TDO) pin, and a Test Clock (TCK) pin.

Abstract: An integrated circuit (IC) including a blocking pin. An IC may include state logic, a test control unit configured to coordinate access by external circuitry to operating state of the state logic during a test mode, and interface pins configured to couple the integrated circuit to the external circuitry. Shared interface pins may provide input signals to the test control unit during the test mode of operation and may perform distinct I/O functions during normal mode operation. A blocking interface pin, when asserted by external circuitry during normal mode operation, may force test signals derived from at least a portion of the shared interface pins by the test control unit into respective quiescent states, such that subsequent to assertion of the blocking pin, the integrated circuit is operable to enter the test mode of operation from the normal mode of operation without resetting operating state of the state logic.

Abstract: An integrated circuit (IC) including a blocking pin. An IC may include state logic, a test control unit configured to coordinate access by external circuitry to operating state of the state logic during a test mode, and interface pins configured to couple the integrated circuit to the external circuitry. Shared interface pins may provide input signals to the test control unit during the test mode of operation and may perform distinct I/O functions during normal mode operation. A blocking interface pin, when asserted by external circuitry during normal mode operation, may force test signals derived from at least a portion of the shared interface pins by the test control unit into respective quiescent states, such that subsequent to assertion of the blocking pin, the integrated circuit is operable to enter the test mode of operation from the normal mode of operation without resetting operating state of the state logic.