Abstract: Electronic scan circuitry includes a decompressor (510), a plurality of scan chains (520.i) fed by the decompressor (510), a scan circuit (502, 504) coupled to the plurality of scan chains (520.i) to scan them in and out, a masking circuit (590) fed by the scan chains (520.i), and a scannable masking qualification circuit (550, 560, 580) coupled to the masking circuit (590), the masking qualification circuit (550, 560, 580) scannable by scan-in of bits by the decompressor (510) along with scan-in of the scan chains (520.i), and the scannable masking qualification circuit (550, 560, 580) operable to hold such scanned-in bits upon scan-out of the scan chains through the masking circuit (590). Other scan circuitry, processes, circuits, devices and systems are also disclosed.

Abstract: A circuit includes a multipath memory having multiple cells and a plurality of sequence generators. Each sequence generator of the plurality of sequence generators drives one separate cell of the multiple cells via an automatic test pattern generator (ATPG) mode signal for each cell. The ATPG mode signal for each cell is configured via a sequence configuration input that controls a timing sequence to test each cell. The state of the ATPG mode signal of each cell selects whether test data or functional data is output from the respective cell.

Abstract: A circuit device is provided with a first codec including a first portion of a logic circuit and a second codec including a second portion of the logic circuit. The circuit device can also include a plurality of first scan chains coupled to the first codec and configured to shift a delayed test vector onto the first codec, wherein the delayed test vector is a test vector with a phase delay. A plurality of second scan chains can be coupled to the second codec and configured to shift the test vector onto the second codec.

Abstract: Electronic scan circuitry includes a decompressor (510), a plurality of scan chains (520.i) fed by the decompressor (510), a scan circuit (502, 504) coupled to the plurality of scan chains (520.i) to scan them in and out, a masking circuit (590) fed by the scan chains (520.i), and a scannable masking qualification circuit (550, 560, 580) coupled to the masking circuit (590), the masking qualification circuit (550, 560, 580) scannable by scan-in of bits by the decompressor (510) along with scan-in of the scan chains (520.i), and the scannable masking qualification circuit (550, 560, 580) operable to hold such scanned-in bits upon scan-out of the scan chains through the masking circuit (590). Other scan circuitry, processes, circuits, devices and systems are also disclosed.

Abstract: A test override circuit includes a memory that includes multiple memory instances. A path selector receives a control signal from automatic test pattern generator equipment (ATE) to control data access to data paths that are operatively coupled between the memory instances and a plurality of logic endpoints. The path selector generates an output signal that indicates which of the data paths is selected in response to the control signal. A gating circuit enables the selected data paths to be accessed by at least one of the plurality of logic endpoints in response to the output signal from the path selector.

Abstract: A circuit includes a multipath memory having multiple cells and a plurality of sequence generators. Each sequence generator of the plurality of sequence generators drives one separate cell of the multiple cells via an automatic test pattern generator (ATPG) mode signal for each cell. The ATPG mode signal for each cell is configured via a sequence configuration input that controls a timing sequence to test each cell. The state of the ATPG mode signal of each cell selects whether test data or functional data is output from the respective cell.

Abstract: A circuit device is provided with a first codec including a first portion of a logic circuit and a second codec including a second portion of the logic circuit. The circuit device can also include a plurality of first scan chains coupled to the first codec and configured to shift a delayed test vector onto the first codec, wherein the delayed test vector is a test vector with a phase delay. A plurality of second scan chains can be coupled to the second codec and configured to shift the test vector onto the second codec.

Abstract: An integrated circuit, comprising functional circuitry and testing circuitry. A first set of pads is operable in a first state for communicating testing signals to the testing circuitry and operable in a second state for communicating input/output signals to the functional circuitry. A second set of pads, differing from the first set of pads, is operable in the second state for communicating testing signals to the testing circuitry for testing signals associated in the second state with the first set of pads.

Abstract: A test override circuit includes a memory that includes multiple memory instances. A path selector receives a control signal from automatic test pattern generator equipment (ATE) to control data access to data paths that are operatively coupled between the memory instances and a plurality of logic endpoints. The path selector generates an output signal that indicates which of the data paths is selected in response to the control signal. A gating circuit enables the selected data paths to be accessed by at least one of the plurality of logic endpoints in response to the output signal from the path selector.

Abstract: An integrated circuit, comprising functional circuitry and testing circuitry. A first set of pads is operable in a first state for communicating testing signals to the testing circuitry and operable in a second state for communicating input/output signals to the functional circuitry. A second set of pads, differing from the first set of pads, is operable in the second state for communicating testing signals to the testing circuitry for testing signals associated in the second state with the first set of pads.

Abstract: A system is provided that includes a memory configured to store test patterns. A first lockstep core and a second lockstep core are configured to receive the same set of test patterns. First scan outputs are generated from the first lockstep core, and second scan outputs are generated from the second lockstep core during a reset of the first lockstep core and the second lockstep core. A comparator can be coupled to the first lockstep core and the second lockstep core and is configured to compare the first scan outputs to the second scan outputs. The first and second lockstep cores can be initialized to a similar state if the first and second scan outputs are the same. The first and second lockstep cores can comprise non-resettable flip flops.

Abstract: A system is provided that includes a memory configured to store test patterns. A first lockstep core and a second lockstep core are configured to receive the same set of test patterns. First scan outputs are generated from the first lockstep core, and second scan outputs are generated from the second lockstep core during a reset of the first lockstep core and the second lockstep core. A comparator can be coupled to the first lockstep core and the second lockstep core and is configured to compare the first scan outputs to the second scan outputs. The first and second lockstep cores can be initialized to a similar state if the first and second scan outputs are the same. The first and second lockstep cores can comprise non-resettable flip flops.

Abstract: A system includes a volatile storage device, a read-only memory (ROM), a memory built-in self-test (BIST) controller and a central processing unit (CPU). The CPU, upon occurrence of a reset event, executes a first instruction from the ROM to cause the CPU to copy a plurality of instructions from a range of addresses in the ROM to the volatile storage device. The CPU also executes a second instruction from the ROM to change a program counter. The CPU further executes the plurality of instructions from the volatile storage device using the program counter. The CPU, when executing the plurality of instructions from the volatile storage device, causes the ROM to enter a test mode and the memory BIST controller to be configured to test the ROM.

Abstract: A circuit includes a false circuit path in a circuit under test having a starting logic point to an end logic point of the path. The false circuit path is designated as a testing path to be excluded during testing of one or more valid timing paths of the circuit under test. A false path gating circuit gates the starting logic point to the end logic point of the false circuit path. The false path gating circuit disables the false circuit path in response to one or more gating controls asserted during the testing of the one or more valid timing paths of the circuit under test.

Abstract: A circuit device is provided with a first codec including a first portion of a logic circuit and a second codec including a second portion of the logic circuit. The circuit device can also include a plurality of first scan chains coupled to the first codec and configured to shift a delayed test vector onto the first codec, wherein the delayed test vector is a test vector with a phase delay. A plurality of second scan chains can be coupled to the second codec and configured to shift the test vector onto the second codec.

Abstract: A system includes a volatile storage device, a read-only memory (ROM), a memory built-in self-test (BIST) controller and a central processing unit (CPU). The CPU, upon occurrence of a reset event, executes a first instruction from the ROM to cause the CPU to copy a plurality of instructions from a range of addresses in the ROM to the volatile storage device. The CPU also executes a second instruction from the ROM to change a program counter. The CPU further executes the plurality of instructions from the volatile storage device using the program counter. The CPU, when executing the plurality of instructions from the volatile storage device, causes the ROM to enter a test mode and the memory BIST controller to be configured to test the ROM.

Abstract: A system is provided that includes a memory configured to store test patterns. A first lockstep core and a second lockstep core are configured to receive the same set of test patterns. First scan outputs are generated from the first lockstep core, and second scan outputs are generated from the second lockstep core during a reset of the first lockstep core and the second lockstep core. A comparator can be coupled to the first lockstep core and the second lockstep core and is configured to compare the first scan outputs to the second scan outputs. The first and second lockstep cores can be initialized to a similar state if the first and second scan outputs are the same. The first and second lockstep cores can comprise non-resettable flip flops.

Abstract: A circuit includes a false circuit path in a circuit under test having a starting logic point to an end logic point of the path. The false circuit path is designated as a testing path to be excluded during testing of one or more valid timing paths of the circuit under test. A false path gating circuit gates the starting logic point to the end logic point of the false circuit path. The false path gating circuit disables the false circuit path in response to one or more gating controls asserted during the testing of the one or more valid timing paths of the circuit under test.

Abstract: Electronic scan circuitry includes a decompressor (510), a plurality of scan chains (520.i) fed by the decompressor (510), a scan circuit (502, 504) coupled to the plurality of scan chains (520.i) to scan them in and out, a masking circuit (590) fed by the scan chains (520.i), and a scannable masking qualification circuit (550, 560, 580) coupled to the masking circuit (590), the masking qualification circuit (550, 560, 580) scannable by scan-in of bits by the decompressor (510) along with scan-in of the scan chains (520.i), and the scannable masking qualification circuit (550, 560, 580) operable to hold such scanned-in bits upon scan-out of the scan chains through the masking circuit (590). Other scan circuitry, processes, circuits, devices and systems are also disclosed.

Abstract: A circuit includes a dynamic core data register (DCDR) cell that includes a data register, a shift register and an output circuit to route the output state of the data register or the shift register to an output of the DCDR in response to an output control input. A clock gate having a gate control input controls clocking of the shift register in response to a first scan enable signal. An output control gate controls the output control input of the output circuit and controls which outputs from the data register or the shift register are transferred to the output of the output circuit in response to a second scan enable signal. The first scan enable signal and the second scan enable signal to enable a state transition of the shift register at the output of the DCDR.