Abstract: A method of designing a circuit having at least one hierarchical block which requires block specific test patterns to facilitate quiescent current testing of the circuit, comprises, for each block, configuring the block and any embedded blocks located one level down in design hierarchy in quiescent current test mode in which input and output peripheral memory elements are configured in internal test mode and in external test mode, respectively; generating quiescent current test patterns which do not result in elevated quiescent current levels and which include a bit for all memory elements in the block and for any peripheral memory elements in any embedded blocks located one level down in design hierarchy; and, if the block contains embedded blocks, synchronizing the test pattern with a corresponding test pattern generated for embedded blocks so that test patterns loaded in scan chains in the block are consistent with test patterns loaded in scan chains in said embedded blocks.

Abstract: A method for use in the hierarchical design of integrated circuits having at least one module, each the module having functional memory elements and combinational logic, the method comprising reading in a description of the circuit; replacing the description of each functional memory element of the modules with a description of a scannable memory element configurable in scan mode and capture mode; partitioning each module into an internal partition and a peripheral partition by converting the description of selected scannable memory elements into a description of peripheral scannable memory elements which are configurable in an internal test mode, an external test mode and a normal operation mode; modifying the description of modules in the circuit description so as to arrange the memory elements into scan chains in which peripheral and internal scannable memory elements of each module are controlled by an associated module test controller when configured in internal test mode; and peripheral scannable memory

Abstract: A method of designing a circuit having at least one hierarchical block which requires block specific test patterns to facilitate quiescent current testing of the circuit, comprises, for each block, configuring the block and any embedded blocks located one level down in design hierarchy in quiescent current test mode in which input and output peripheral memory elements are configured in internal test mode and in external test mode, respectively; generating quiescent current test patterns which do not result in elevated quiescent current levels and which include a bit for all memory elements in the block and for any peripheral memory elements in any embedded blocks located one level down in design hierarchy; and, if the block contains embedded blocks, synchronizing the test pattern with a corresponding test pattern generated for embedded blocks so that test patterns loaded in scan chains in the block are consistent with test patterns loaded in scan chains in said embedded blocks.

Abstract: A method for at-speed testing high-performance digital systems and circuits having combinational logic and memory elements that may be both scannable and non-scannable is performed by enabling at least two clock pulses during a capture sequence following a shift sequence. The method provides for initialization of any non-scannable memory elements via the scannable memory elements at the beginning of the test before an at-speed test is performed. During initialization, control logic generates a signal to disable the generation of system clock pulses for capture. Instead, only one clock cycle derived from the test clock or a system clock is generated to initialize the non-scannable elements. The number of shift sequences required depends on the maximum number of non-scannable elements that must be traversed between two scannable memory elements. During the same initialization period, the output response analyzer is disabled since unknown data values will present in the stream of data shifted out.

Abstract: A method of and computer program product for modeling a logic circuit having combinational logic and latches, in which the latches are clocked by one of a first clock phase, a second clock phase or a pulse derived from the second clock phase, a subset of latches being scannable, comprises, for each latch in the logic circuit, associating the latch with one of the first and second clock phase; and when latch is associated with the first clock phase, modeling the latch as a buffer connected between the data input and output of latch; and when the latch is associated with the second clock phase, modeling the latch as an edge-triggered flip-flop having the same data input, data output and clock input as the latch.

Abstract: A method of and computer program product for modeling a logic circuit having combinational logic and latches, in which the latches are clocked by one of a first clock phase, a second clock phase or a pulse derived from the second clock phase, a subset of latches being scannable, comprises, for each latch in the logic circuit, associating the latch with one of the first and second clock phase; and when latch is associated with the first clock phase, modeling the latch as a buffer connected between the data input and output of latch; and when the latch is associated with the second clock phase, modeling the latch as an edge-triggered flip-flop having the same data input, data output and clock input as the latch.

Abstract: A method and digital system for testing scannable memory and combinational networks. The scannable memory is configurable into several scan chains. Each chain may have a different effective clock rate, as determined by respective clock enable signals. The method and digital system allow scan testing of digital circuits that use a single operational clock rate and several functional clock enable signals to effect slower lock operating rates. The digital system includes memory elements having scan enable and clock enable inputs.