Semiconductor integrated circuit device and device for testing same
View Patent ↗A device for testing a semiconductor integrated circuit device has a test board on which the semiconductor integrated circuit device to be tested is removably mounted, and a two-pulse generator mounted on the test board, for generating two pulses spaced from each other by a pulse interval equal to the period of a test clock for the delay test, from the test clock, and supplying the generated two pulses to the scan path test circuit. The device also has a PLL circuit for multiplying the frequency of the test clock and supplying a signal having the multiplied-frequency to the two-pulse generator.
1. A test circuit for a semiconductor integrated circuit device for being put to a delay test using a scan path test circuit incorporated on said semiconductor integrated circuit device for a scan path test, comprising:
a two-pulse generator for generating two pulses spaced from each other by a pulse interval equal to a period of a test clock for the delay test, said test clock being input from an external source, and supplying the generated two pulses to the scan path test circuit, said two-pulse generator comprises a gate signal generator for generating a gate signal to extract two pulses from said test clock and a latch gate circuit for outputting two pulses from said test clock according to said gate signal, said gate signal generator generating one of a positive and negative edge of said gate signal at a predetermined time delay after a negative edge of said test clock as measured from an input timing of a control signal.
2. The test circuit according to claim 1 , wherein said test circuit is fabricated in said semiconductor integrated circuit device and further comprises:
a PLL circuit for multiplying a frequency of said test clock and supplying a signal having the multiplied-frequency to said two-pulse generator.
3. The test circuit according to claim 1 , wherein said test circuit is mounted on a test board, and said semiconductor integrated circuit device is removably mounted on said test board.
4. The test circuit according to claim 3 , further comprising: a PLL circuit for multiplying the frequency of said test clock and supplying a signal having the multiplied-frequency to said two-pulse generator.
5. The test circuit according to claim 3 , further comprising: a clock generator for outputting said test clock. a test board on which a semiconductor integrated circuit device is removably mounted.
6. The test circuit according to claim 3 , furthering comprising: a frequency divider mounted on said test board, for dividing the frequency of said test clock into a lower frequency.
7. The test circuit according to claim 1 , further comprising: a clock generator for outputting said test clock, wherein said two-pulse generator is fabricated in said semiconductor integrated circuit device, and said semiconductor integrated circuit device is removably mounted to a test board, and said clock generator is mounted on said test board.
8. The test circuit according to claim 7 , further comprising: a PLL circuit for multiplying the frequency of said test clock and supplying a signal having the multiplied-frequency to said two-pulse generator, wherein said PLL circuit is fabricated in said semiconductor integrated circuit device.
9. The test circuit according to claim 7 , further comprising: a second PLL circuit mounted on said test board, for multiplying a frequency of said test clock and supplying a signal having the multiplied-frequency to said semiconductor integrated circuit device.
10. The test circuit according to claim 7 , further comprising: a frequency divider mounted on said test board, for dividing a frequency of said test clock into a lower frequency.
11. The test circuit according to claim 1 , wherein said gate signal generator comprises a control circuit for adjusting a timing of said gate signal.
12. The test circuit according to claim 11 , wherein said control circuit counts said test clock for adjusting said timing of said gate signal.