摘要:
The interface circuit includes n buffer circuits, switches for connecting an external pin of a tester to input nodes of n buffer circuits and connecting output nodes of n buffers respectively to n DUTs when a signal is provided from the tester to n DUTs, and successively connecting n DUTs to the external pin of the tester by a prescribed time period when voltage-ampere characteristics of n DUTs are measured. Therefore the number of devices that can be measured by the tester at a time can be increased by n times. As a result, the test cost can be reduced and the test accuracy can be improved.
摘要:
A waveform and timing generation circuit 28, a skew circuit 30, and a pin driver 32 are provided for each of a plurality of I/O terminals 22 corresponding respectively to a plurality of pins furnished on an LSI. A relay 44 and a loop control circuit 46 are provided to feed an output signal of the pin driver 32 back to an input side of the waveform and timing generation circuit 28. A skew board 100 is used to adjust the skew circuit 30, whereby the initial timing calibration is carried out. With the skew circuit 30 thus adjusted, oscillations are generated over the feedback path, and the number of resulting pulses is counted (to obtain pulse cycles). When the skew circuit 30 is adjusted so that the pulse count above matches the number of pulses generated during oscillations, a simplified form of timing calibration is implemented.
摘要:
In a test circuit, a determination circuit conducts a function test to determine whether timing of a slope section of waveform of an analog signal ANS of a measurement target device is within a range of specifications. An ADC performs AD-conversion only when a potential of analog signal ANS is within a range between reference potentials VOL, VOH. An analysis unit analyzes digital data from the ADC, and conducts a sloping waveform test to evaluate a sloping state of the waveform of analog signal ANS. Therefore, the slope section of the waveform of analog signal ANS of the device can be subjected to AD-conversion in a voltage range divided in arbitrary number of sections within a range of arbitrary voltage amplitude without requiring a large-capacity storage circuit. The function test by a determination circuit and the sloping waveform test by the analysis unit can be performed in parallel.
摘要:
In a test circuit, a determination circuit conducts a function test to determine whether timing of a slope section of waveform of an analog signal ANS of a measurement target device is within a range of specifications. An ADC performs AD-conversion only when a potential of analog signal ANS is within a range between reference potentials VOL, VOH. An analysis unit analyzes digital data from the ADC, and conducts a sloping waveform test to evaluate a sloping state of the waveform of analog signal ANS. Therefore, the slope section of the waveform of analog signal ANS of the device can be subjected to AD-conversion in a voltage range divided in arbitrary number of sections within a range of arbitrary voltage amplitude without requiring a large-capacity storage circuit. The function test by a determination circuit and the sloping waveform test by the analysis unit can be performed in parallel.
摘要:
An LSI testing apparatus of the invention comprises: a plurality of pins P1, P2, . . . PN; function units 10, 11 and 12 which supply the pins with LSI testing signals, which have functions for making judgments on tests, and which are furnished for each of the pins; and clock mask function units 15A and 15B furnished on the input side of each function unit. Upon testing, any unused pin and function are detected so as to mask the clock mask function unit corresponding to the detected pin and function, whereby power dissipation is reduced in terms of unused pins and functions.
摘要:
A jitter measurement circuit includes: a conversion section sampling one of a reference signal and a measurement target signal in response to the other of the signals, thereby obtaining a sampling data string; and a determination section measuring jitter of the measurement target signal on the basis of the sampling data string obtained by the conversion section. Since the reference signal is a stable signal having a predetermined cycle, the sampling data string as a measurement result depends on the measurement target signal. Therefore, it is possible to simply measure jitter level in accordance with irregularity of the measurement result and on the basis of relative measurement to expected value data.
摘要:
A semiconductor test apparatus includes an analog-to-digital converter for converting into a digital signal an analog output from a circuit under test; a test-apparatus-ADC-control-signal generation circuit for generating a control signal for the analog-to-digital converter in accordance with an activation signal entered from the outside; a measured data memory for storing, as measured data for each conversion, a signal output from the analog-to-digital converter; an address counter for generating an address signal for the measured data memory; a DAC counter for generating data to be input to the circuit under test; and a data write control circuit which produces, in response to a flag signal output from the analog-to-digital converter and representing that conversion is being performed, an update signal for the address counter, a memory write signal for the measured data memory, and an update signal for the DAC counter.
摘要:
In a threshold analysis method obtaining threshold voltages of all bits in a flash memory through single processing, fail bit map information is examined in order from a smaller voltage applied to the flash memory. As to a bit exhibiting a value, read from the flash memory, first mismatching a determination value, the threshold voltage is settled on the basis of a voltage applied when the bit fails in reading.
摘要:
There are provided a test apparatus and method for testing a semiconductor integrated circuit which enables improvements in the ease of operation and convenience of a BOST device and shortening of a test time. Numeric codes are assigned to tests. A test apparatus is equipped with memory and an analysis section. A test requirement table—in which hardware requirements required for conducting a test are set on a per-numeric-code basis—is stored in the memory. Test requirements corresponding to a numeric code are read from the memory, whereupon a test is performed. The analysis section analyzes a digital test output and sends the result of analysis to an external controller.
摘要:
A semiconductor test apparatus and method for performing a test on a nonvolatile semiconductor memory such as a flash memory while preventing excessive erasing with reliability. In each erase operation, all addresses are scanned to fetch an error address and error data into a catch memory. Then, on the basis of error information (error address and error data), a rewrite operation is performed to write data on all memory cells. The write data varies according to a comparison result between an address signal and an error address signal. If they disagree, a “0” is written on a memory cell at the address. If they agree, a “0” is written on a “pass” memory cell and a “1” is virtually written on a fail memory cell.