Semiconductor test apparatus for controlling tester
A tester instruction generation unit generates a tester instruction for terminals of a plurality of devices connected to a tester based on an instruction of a user program and causes an instruction storage unit to store the tester instruction. A transfer mode setting unit sets a transfer mode to either a successive transfer mode or a batch transfer mode, based on the number of tester instructions in the instruction storage unit or an instruction of the user program. A transfer control unit transmits the tester instruction in the instruction storage unit to the tester in accordance with the set transfer mode.
1. A semiconductor test apparatus for controlling a tester to which a plurality of devices are connected, comprising:
a user program execution unit executing an instruction of a user program;
an instruction generation unit generating tester instructions for terminals of the plurality of devices connected to said tester based on the instruction of said user program;
an instruction storage unit storing generated said tester instructions;
a transfer mode setting unit setting a transfer mode to either a successive transfer mode or a batch transfer mode based on one of the instruction of said user program and information on how many tester instructions are stored in said instruction storage unit;
a transfer control unit transmitting the tester instructions in said instruction storage unit to said tester in accordance with set said transfer mode;
a memory storing a list of abnormal devices among the plurality of devices connected to said tester; and
a device management unit identifying an abnormal device among the plurality of devices connected to said tester in accordance with a signal transmitted from said tester and updating the list of said abnormal devices, wherein
said instruction generation unit generates the tester instructions as many as terminals of a normal device among the plurality of devices connected to said tester, by referring to the list of said abnormal devices based on the instruction of said user program,
said transfer mode setting unit sets the transfer mode to a mode shorter in transfer time period of the successive transfer mode and the batch transfer mode based on the information on how many tester instructions are stored in said instruction storage unit, and
the transfer time period of the successive transfer mode is (ts 1 +ts 2 )×N and the transfer time period of the successive transfer mode is tb 1 +tb 2 ×N, in which ts 1 represents a time period required for pre-processing for transfer in the successive transfer mode, ts 2 represents a time period required for transfer of one tester instruction from said instruction storage unit to said tester in the successive transfer mode, tb 1 represents a time period required for pre-processing for transfer in the batch transfer mode, tb 2 represents a time period required for transfer of one tester instruction from said instruction storage unit to said tester in the batch transfer mode, and N represents the information on how many tester instructions are stored in said instruction storage unit.
2. The semiconductor test apparatus according to claim 1 , wherein
said transfer mode setting unit sets said transfer mode when said transfer mode setting unit receives a pattern execution instruction from said user program execution unit.
3. The semiconductor test apparatus according to claim 1 , comprising a test item storage unit storing a test item of which test in said device has failed in said batch transfer mode, wherein
said transfer mode setting unit sets the transfer mode for the tester instructions generated from an instruction included in the test item stored in said test item storage unit to said successive transfer mode.
4. The semiconductor test apparatus according to claim 3 , wherein
said transfer mode setting unit sets the transfer mode for the tester instructions generated from the instruction included in said user program in a pretest to said batch transfer mode, and
said device management unit identifies a test item which has failed in accordance with a signal transmitted from said tester and writes identified said test item in said test item storage unit.
5. The semiconductor test apparatus according to claim 1 , comprising a test item storage unit storing a test item of which first measurement value obtained in a test in said device in said successive transfer mode and second measurement value obtained in a test in said device in said batch transfer mode are different from each other by a prescribed value or more, wherein
said transfer mode setting unit sets the transfer mode for the tester instructions generated from an instruction of the test item stored in said test item storage unit to said successive transfer mode.
6. The semiconductor test apparatus according to claim 5 , wherein
said transfer mode setting unit sets the transfer mode for the tester instructions generated from the instruction included in said user program in a first pretest to said successive transfer mode,
said device management unit writes said first measurement value of each test item in said test item storage unit in accordance with a signal transmitted from said tester,
said transfer mode setting unit sets the transfer mode for the tester instructions generated from the instruction included in said user program in a second pretest to said batch transfer mode,
said device management unit writes said second measurement value of each test item in said test item storage unit in accordance with a signal transmitted from said tester, and
said device management unit writes the test item of which said first measurement value and said second measurement value are different from each other by the prescribed value or more in said test item storage unit.