Abstract: A computer implemented method, testing system, computer usable program code, and apparatus are provided for measuring microprocessor susceptibility to internal noise A noise generator modulates a clock signal to generate noise on a targeted component within a microprocessor. A function generator executes microprocessor functions on a plurality of functional components within the microprocessor. A maximum execution frequency on the plurality of functional components is then measured and a set of frequency ranges where the functional components are susceptible to the generated noise is determined.

Abstract: In-band firmware executes instructions which cause commands to be sent on a coherency fabric. Fabric snoop logic monitors the coherency fabric for command packets that target a resource in one of the support chips attached via an FSI link. Conversion logic converts the information from the fabric packet into an FSI protocol. An FSI command is transmitted via the FSI transmit link to an FSI slave of the intended support chip. An FSI receive link receives response data from the FSI slave of the intended support chip. Conversion logic converts the information from the support chip received via the FSI receive link into the fabric protocol. Response packet generation logic generates the fabric response packet and returns it on the coherency fabric. An identical FSI link between a support processor and support chips allows direct access to the same resources on the support chips by out-of-band firmware.

Abstract: A method and apparatus are provided for a support interface for memory-mapped resources. A support processor sends a sequence of commands over and FSI interface to a memory-mapped support interface on a processor chip. The memory-mapped support interface updates memory, memory-mapped registers or memory-mapped resources. The interface uses fabric packet generation logic to generate a single command packet in a protocol for the coherency fabric which consists of an address, command and/or data. Fabric commands are converted to FSI protocol and forwarded to attached support chips to access the memory-mapped resource, and responses from the support chips are converted back to fabric response packets. Fabric snoop logic monitors the coherency fabric and decodes responses for packets previously sent by fabric packet generation logic. The fabric snoop logic updates status register and/or writes response data to a read data register. The system also reports any errors that are encountered.

Abstract: A circuit for measuring timing uncertainty in a clocked digital path and in particular, the number of logic stages completed in any clock cycle. A local clock buffer receives a global clock and provides a complementary pair of local clocks. A first local (launch) clock is an input to a delay line, e.g., 3 clock cycles worth of series connected inverters. Delay line taps (inverter outputs) are inputs to a register that is clocked by the complementary clock pair to capture progression of the launch clock through the delay line and identify any variation (e.g., from jitter, VDD noise) in that progression. Global clock skew and across chip gate length variation can be measured by cross coupling launch clocks from a pair of such clock buffers and selectively passing the local and remote launch clocks to the respective delay lines.

Abstract: A method and apparatus for testing path delays in a high-speed boundary scan implementation overcomes limitations imposed by pipelined high-speed clocking architectures used in integrated circuits. A special phase hold circuit provides a mechanism for clocking circuits undergoing dynamic tests, permitting the dynamic test to produce proper results when the integrated circuit under test is clocked with a high-speed distributed clock. The functional logic clock enable is pipelined to synchronize the functional mode clock with the test mode clock when the tester mode is switched.