摘要:
In one aspect, an electronic device that has been partitioned into segments by using clock gating or signal gating is tested. One of the segments that is a source of a failure is identified. Diagnostic procedures are applied to the identified segment to determine a cause of the failure.
摘要:
A method for locally generating a ratio clock on a chip includes generating a global clock signal having a global clock cycle. A centralized state machine includes a counter going through a complete cycle in response to a non-integer number of global clock cycles, the state machine generating a control signal in response to the counter. The control signal is provided to staging latches, the staging latches generating a clock high signal and a clock low signal. Local pass gates generate an (n+0.5)-to-1 clock signal in response to the global clock signal, the clock high signal and the clock low signal.
摘要:
An apparatus and method is provided that combines both self test and functional features in a single latch circuit, which may be used with an SRAM array and is usefully embodied as an L1-L2 latch. During partial writes from an SRAM array, data bits of unknown state are inhibited from entering the latch circuit, while data for testing is allowed to enter. In one useful embodiment of the invention the latch circuit is used with a mode control that provides mode select signals to operate the latch circuit in one of a plurality of modes, including at least full write and partial write modes. The latch circuit further includes a data hold circuit for selectively receiving and storing data coupled to the latch circuit. A first enabling circuit responsive to the mode select signals enables the hold circuit to receive all the data contained in the array during a full write mode, and further enables the hold circuit to receive only some of the data bits contained in the array during a partial write mode, while preventing other data bits of “X” state from entering the latch circuit. A second enabling circuit enables the data hold circuit to receive data bits from a self test source in place of respective data bits from the SRAM array that are prevented from entering the latch circuit.
摘要:
In a first aspect, a first method is provided for isolating a defect in a scan chain. The first method includes the steps of (1) modifying a first test mode of one or more of a plurality of latches included in the scan chain; (2) operating the one or more latches whose first test modes are modified in the modified first test mode; and (3) operating one or more of the plurality of latches included in the scan chain in a second test mode. Numerous other aspects are provided.
摘要:
Memory array built in self testing utilizing including a simple data history table. The table is used to track failing locations observed during any level of assembly test of processor or logic semiconductor chips where the chips contain SRAM macros with redundant elements for failure relief.
摘要:
A computing system is provided which includes a processor having a cache memory. The cache memory includes a plurality of independently configurable subdivisions, each subdivision including a memory array. A service element (SE) of the computing system is operable to cause a built-in-self-test (BIST) to be executed to test the cache memory, the BIST being operable to determine whether any of the subdivisions is defective. When it is determined that one of the subdivisions of the cache memory determined defective by the BIST is non-repairable, the SE logically deletes the defective subdivision from the system configuration, and the SE is operable to permit the processor to operate without the logically deleted subdivision. The SE is further operable to determine that the processor is defective when a number of the defective subdivisions exceeds a threshold.
摘要:
In one aspect, an electronic device that has been partitioned into segments by using clock gating or signal gating is tested. One of the segments that is a source of a failure is identified. Diagnostic procedures are applied to the identified segment to determine a cause of the failure.
摘要:
Systems, methods and apparatus are provided for isolating a defect in a scan chain. The invention includes modifying a first test mode of a plurality of latches included in a scan chain, operating the latches in the modified first test mode, and operating the plurality of latches included in the scan chain in a second test mode. A portion of the scan chain adjacent and following a stuck-@-0 or stuck-@-1 fault in the scan chain may store and/or output a value complementary to the value on the output of the previous portion of the scan chain due to the fault. Such values may be unloaded from the scan chain and used for diagnosing (e.g., isolating a defect in) the defective scan chain. Numerous other aspects are provided.
摘要:
Circuitry for locally generating a ratio clock on a chip. The circuitry includes circuitry for generating a global clock signal having a global clock cycle. A state machine includes a counter going through a complete cycle in response to a non-integer number of global clock cycles. The state machine generates a control signal in response to the counter. Staging latches receive the control signal and generate a clock high signal and a clock low signal, the clock high signal and the clock low signal having patterns derived from a waveform of a target divided ratio clock, the clock high signal and the clock low signals have patterns that match the targeted divided clock frequency and duty cycle. A local pass gate receives the clock low signal and the clock high signal and generates an (n+0.5)-to−1 clock signal in response to the global clock signal, the clock high signal and the clock low signal.
摘要:
The output register of an array and the Multiple Input Signature Register (MISR) logic is implemented with one set of L1/L2 master/slave latches and single additional slave latch. This new combined logic uses less critical area on a chip without a performance impact on the array access time or circuit testing.
摘要翻译:阵列的输出寄存器和多输入签名寄存器(MISR)逻辑由一组L 1 / L 2主/从锁存器和单个附加从锁存器实现。 这种新的组合逻辑在芯片上使用较少的关键区域,而不会对阵列访问时间或电路测试产生性能影响。