Wafer test trigger signal generating circuit of a semiconductor memory apparatus, and a wafer test circuit using the same

1. A wafer test trigger signal generating circuit of a semiconductor memory apparatus, comprising:

an enable timing control unit configured to generate an enable signal by using a plurality of address signals; and

a trigger signal generating unit configured to generate a test trigger signal, which designates a decoding timing of a test mode defined by the plurality of address signals, in response to the enable signal,

wherein the enable timing control unit generates the enable signal by using an address signal that is firstly enabled among the plurality of address signals.

2. The wafer test trigger signal generating circuit of claim 1 , wherein the enable timing control unit enables the enable signal when a predetermined time interval has lapsed from an enabling timing of the address signal that is firstly enabled.

3. The wafer test trigger signal generating circuit of claim 2 , wherein the enable timing control unit enables the enable signal when a time corresponding to about one-half of an enable duration of the address signal that is firstly enabled has lapsed from the enabling timing of the address signal.

4. The wafer test trigger signal generating circuit of claim 3 , wherein the enable timing control unit includes:

an enable signal generating unit configured to enable a preliminary enable signal at the enabling timing of the address signal that is firstly enabled; and

a pulse generating unit configured to enable the enable signal when a time corresponding to about one-half of the enable duration of the address signal that is firstly enabled has lapsed after the preliminary enable signal has been enabled.

5. The wafer test trigger signal generating circuit of claim 1 , wherein the test trigger signal generating unit generates the test trigger signal having a predetermined activation period in response to an enablement of the enable signal.

6. A wafer test circuit of a semiconductor memory apparatus, comprising:

a wafer test trigger signal generating circuit configured to generate a test trigger signal that designates a timing for a plurality of test modes by using a plurality of address signals when a wafer of the semiconductor memory apparatus is tested; and

a decoding circuit configured to enable one of the plurality of test modes by decoding the plurality of address signals during an enable period of the test trigger signal,

wherein the wafer test trigger signal generating circuit generates the test trigger signal in response to an enable signal generated by using an address signal that is firstly enabled among the plurality of address signals.

7. The wafer test circuit of claim 6 , wherein the wafer test trigger signal generating circuit includes:

an enable timing control unit configured to generate the enable signal by using the plurality of address signals; and

a trigger signal generating unit configured to generate the test trigger signal that designates the decoding timing of the test modes defined by the plurality of address signals in response to the enable signal.

8. The wafer test circuit of claim 7 , wherein the enable timing control unit generates the enable signal by using the address signal that is firstly enabled among the plurality of address signals.

9. The wafer test circuit of claim 8 , wherein the enable timing control unit enables the enable signal when a predetermined time interval has lapsed from an enabling timing of the address signal that is firstly enabled.

10. The wafer test circuit of claim 9 , wherein the enable timing control unit enables the enable signal when a time corresponding to about one-half of an enable duration of the address signal that is firstly enabled has lapsed from the enabling timing of the address signal.

11. The wafer test circuit of claim 10 , wherein the enable timing control unit includes:

an enable signal generating unit configured to enable a preliminary enable signal at the enabling timing of the address signal that is firstly enabled; and

a pulse generating unit configured to enable the enable signal when a time corresponding to about one-half of the enable duration of the address signal that is firstly enabled has lapsed after the preliminary enable signal has been enabled.

12. The wafer test circuit of claim 7 , wherein the test trigger signal generating unit generates the test trigger signal having a predetermined activation period in response to an enable of the enable signal.

13. A wafer test trigger signal generating circuit of a semiconductor memory apparatus, comprising:

an enable timing control unit configured to generate an enable signal by using a plurality of address signals;

an enable signal generating unit configured to enable a preliminary enable signal at an enabling timing of a first enabled one of a plurality of address signals;

a pulse generating unit configured to enable the preliminary enable signal when a time corresponding to about one-half of an enable duration of the first enabled address signal has lapsed after the preliminary enable signal has been enabled; and

a trigger signal generating unit configured to generate a test trigger signal in response to the enable signal, wherein the test trigger signal designates a decoding timing of a test mode defined by the plurality of address signals.

14. The wafer test trigger signal generating circuit of claim 13 , wherein the test trigger signal generating unit generates the test trigger signal having a predetermined activation period in response to an enablement of the preliminary enable signal.

15. A semiconductor memory apparatus, comprising:

a wafer test circuit including: a wafer test trigger signal generating circuit configured to generate a test trigger signal that designates a timing for a plurality of test modes by using a plurality of address signals when a wafer of the semiconductor memory apparatus is tested; and

a decoding circuit configured to enable one of the plurality of test modes by decoding the plurality of address signals during an enable period of the test trigger signal,

wherein the wafer test trigger signal generating circuit generates the test trigger signal in response to an enable signal generated by using an address signal that is firstly enabled among the plurality of address signals.

16. The semiconductor memory apparatus of claim 15 , wherein the wafer test trigger signal generating circuit includes:

an enable timing control unit configured to generate the enable signal by using the plurality of address signals; and

a trigger signal generating unit configured to generate the test trigger signal that designates the decoding timing of the test modes defined by the plurality of address signals in response to the enable signal.

17. The semiconductor memory apparatus of claim 16 , wherein the enable timing control unit generates the enable signal by using the address signal that is firstly enabled among the plurality of address signals.

18. The semiconductor memory apparatus of claim 17 , wherein the enable timing control unit enables the enable signal when a predetermined time interval has lapsed from an enabling timing of the address signal that is firstly enabled.

19. The semiconductor memory apparatus of claim 18 , wherein the enable timing control unit enables the enable signal when a time corresponding to about one-half of an enable duration of the address signal that is firstly enabled has lapsed from the enabling timing of the address signal.

20. The semiconductor memory apparatus of claim 19 , wherein the enable timing control unit includes:

an enable signal generating unit configured to enable a preliminary enable signal at the enabling timing of the address signal that is firstly enabled; and

a pulse generating unit configured to enable the enable signal when a time corresponding to about one-half of the enable duration of the address signal that is firstly enabled has lapsed after the preliminary enable signal has been enabled.