Disclosed are representative embodiments of methods, apparatus, and systems for test scheduling and test access in a test compression environment. Clusters of test patterns for testing a plurality of cores in a circuit are formed based on test information that includes compressed test data, corresponding tester channel requirements and correlated cores. The formation of test pattern clusters is followed by tester channel allocation. A best-fit scheme or a balanced-fit scheme may be employed to generate channel allocation information. A test access circuit for dynamic channel allocation can be designed based on the channel allocation information.

An implementation of a system disclosed herein includes a decompressor logic with the capability to vary a level of decompression of a scanning input signal based on value of compression program bits and a compressor logic to generate a scanning output signal, the compressor logic including a plurality of XOR logics, wherein the output of the plurality of XOR logics is selected based on the compression program bits.

The disclosure describes novel methods and apparatuses for accessing test compression architectures (TCA) in a device using either a parallel or serial access technique. The serial access technique may be controlled by a device tester or by a JTAG controller. Further the disclosure provides an approach to access the TCA of a device when the device exists in a daisy-chain arrangement with other devices, such as in a customer's system. Additional embodiments are also provided and described in the disclosure.

Method and apparatus to test an integrated circuit includes retrieving power distribution data relating to an integrated circuit and designating a segment that includes at least one component of the integrated circuit. A switching limit associated with the segment may be set based on the power distribution data. Processes further generate a testing pattern that includes the determined switching limit associated with the segment.

Various aspects of the disclosed technology relate to streaming data to circuit blocks in a circuit. A system for streaming data in a circuit comprises a first network comprising first data channels and first interface devices and a second network comprising second data channels and second interface devices. Each of the first interface devices is coupled to ports of one of circuit blocks in the circuit and configurable to transport a plurality of equal-sized data packets consecutively. Each of the second interface devices is coupled to one of the first interface devices and configurable to transport configuration data to the first interface devices. The configuration data comprise data for determining whether or not a first interface device is activated and data for determining which bit or bits of each of the plurality of data packets to be captured, replaced, or captured and replaced by an activated first interface device.

An implementation of a system disclosed herein includes a decompressor logic with the capability to vary a level of decompression of a scanning input signal based on value of compression program bits and a compressor logic to generate a scanning output signal, the compressor logic including a plurality of XOR logics, wherein the output of the plurality of XOR logics is selected based on the compression program bits.

Various aspects of the disclosed technology relate to using data throttling to generate streaming data for streaming networks in circuits. A plurality of equal-sized data packets to be transported consecutively in a network to the plurality of circuit blocks are generated. The number of bits in each of the plurality of equal-sized data packets assigned to a circuit block requiring longest data loading time is equal to the number of input ports of the circuit block, while the number of bits in each of the plurality of data packets assigned to each of the rest of the plurality of circuit blocks is equal to or smaller than the number of input ports of the each of rest of the plurality of circuit blocks, determined based on the longest data loading time and data loading time for the each of rest of the plurality of circuit blocks.

The invention relates to a microchip with a multiplicity of reconfigurable test structures, wherein the microchip has a test input (TDI) and a test output (TDO), wherein the multiplicity of test structures can be connected to the test input (TDI) and the test output (TDO), wherein one intermediate memory is provided for each of the multiplicity of test structures, wherein each of the multiplicity of test structures can be tested separately and concurrently with the aid of the respective intermediate memory and a corresponding individual control.

The disclosure describes novel methods and apparatuses for accessing test compression architectures (TCA) in a device using either a parallel or serial access technique. The serial access technique may be controlled by a device tester or by a JTAG controller. Further the disclosure provides an approach to access the TCA of a device when the device exists in a daisy-chain arrangement with other devices, such as in a customer's system. Additional embodiments are also provided and described in the disclosure.

Method and apparatus to test an integrated circuit includes retrieving power distribution data relating to an integrated circuit and designating a segment that includes at least one component of the integrated circuit. A switching limit associated with the segment may be set based on the power distribution data. Processes further generate a testing pattern that includes the determined switching limit associated with the segment.