Summary of the invention
The technical problem to be solved in the present invention provides a kind of method for parallelly detecting synchronous communication chips, and it can improve the same quantitation of parallelly detecting synchronous communication chips, and then improves concurrent testing efficient, reduces test duration and cost.
For solving the problems of the technologies described above, method for parallelly detecting synchronous communication chips of the present invention is to adopt following technical scheme to realize, at first, on silicon chip, use shift register that a plurality of chips are coupled together, change method also by string test signal is input on all chip under test; Then, be input on the I/O mouth of tester by the method for also changeing string by the output data of shift register a plurality of chips; The last test instrument obtains PASS/FAIL (pass/fail) result of each chip under test by the data of reading in being carried out data processing.
Adopt method of the present invention can obviously shorten the test duration of chip.For example adopt general tester to test simultaneously to 16 chips.And 16 chip simultaneous tests can further be extended to 64 chip simultaneous tests after adopting method of the present invention, testing efficiency has reached about 3~4 times of 16 chip simultaneous tests, it is about about 70% that this means that also the test duration of one piece of chip has shortened, and greatly reduces the testing cost of chip.
Embodiment
Boundary scan is a kind of more advanced means of testing, and it couples together each module in the chip by shift register and tests, and realizes controllability and the ornamental tested with this.The present invention promptly adopts the method for boundary scan that a plurality of synchronous communication chips are carried out concurrent testing, can effectively improve testing efficiency.
Method for parallelly detecting synchronous communication chips of the present invention is to regard a plurality of chips on the silicon chip as on the chip a plurality of modules, is connected on a plurality of chips with the parallel port on the shift register.Concrete solution is: as shown in Figure 1, on same silicon chip, on marking groove, make four two-way input and output shift registers, the PAD (pressure point) that the parallel delivery outlet of shift register is connected to each chip goes up on the signal end (for example I/O PAD), the probe of tester is pricked on the serial input port of four two-way input and output shift registers.PAD among Fig. 1 is the thin slice of an aluminium on each input/output port on the chip, and probe will be pricked in the above during test, is used to connect external pin during encapsulation.Like this, change method also by string test signal is input to all chip under test.
Utilize data setup time, export the data of concurrent testing successively on the I/O of tester mouth, (before rising edge clock) is with each data parallel output before data are effective.When the chip output data, earlier shift register is set to input state, and the output data (the last signal of PAD) of each chip is input in the I/O mouth of tester successively by shift register.Like this, by the method for also changeing string the output data of a plurality of chips is input to the I/O mouth of tester.On the ECR that on the tester I/O mouth input signal is write successively tester (ERROR CATCH ram error is handled internal memory), tester carries out the judgement of PASS/FAIL by the last data of ECR are handled realization to four corresponding on shift register chips, obtains test result.
As one embodiment of the present of invention, as seen in Figure 2, adopt method of the present invention to expand to the test resource of an original test channel.Make original two test channel can only carry out the same survey of two chips, can carry out the same survey of 8 chips, even under the situation of frequency and test duration permission, can also further increase the same survey number of chip through increasing shift register.
In test process, earlier the data in the shift register are moved to left at signal before effective time (be data effectively before) by tester, the data that needs are input on each chip (being DUT, measured device) move on on each chip.Then, be in input state, the data on the shift register are input on the chip, realize with of PATTERN (test vector) input test of a test channel a plurality of chip under test with this by the clock enabling signal chip.
When chip is in output state, make shift register be in parallel input state earlier, the output of a plurality of chip under test is input on the shift register.Then, before the next clock period arrives, the data on the shift register are moved to right, realize with of the collection of a test channel to a plurality of chip under test data.
At last, the data with the shift register input deposit among the ECR of tester laterally storage continuously in.Horizontal width is the same survey number on the same test channel.Vertically reading of data and effect reference value relatively just can be judged the current vertically PASS/FAIL result of this row chip under test successively as long as pass through when judging chip PASS/FAIL.
It is 4,8,16 or 32 that a test channel of tester can be pricked the chip of realizing concurrent testing on a shift register.
The probe of each test channel of tester can be pricked the shift register of chip chamber and expand, and realizes more chip is carried out with surveying.
The used probe of tester only need be made the probe of a chip, probe is pricked the test that realizes on the serial I/O port of shift register a plurality of chips.
After silicon chip was cut apart, the shift register in the scribe line all will be scratched with the line that is connected a plurality of chip chambers.The chip that originally links together on silicon chip will be separated.