JP2009087528A - Semiconductor integrated circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit capable of reducing a chip size. <P>SOLUTION: The semiconductor integrated circuit includes a plurality of input/output terminals for transmitting input/output data and a plurality of memory cell array areas to which bits of different in number among the input/output data are assigned, and addresses different from one another are assigned. By a bit line switch, a plurality of bit lines connected to memory cells of each memory cell array area are connected to a shared bit line formed in the memory cell array area. A sense amplifier is connected to the shared bit line to amplify data of the bit line transmitted through the bit line switch. By making the input/output data of different in bits share the sense amplifier, the number of the sense amplifiers can be reduced and the chip size can be reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor integrated circuit having a data compression test function that aggregates data signals and efficiently performs a read / write operation test.

  In memory LSIs such as DRAM (Dynamic Random Access Memory), the storage capacity is increasing year by year. Due to the increase in storage capacity, these memory LSI address spaces have become sufficiently secured even when the input / output terminals are 16 bits or 32 bits (generally referred to as multi-bit products). . For example, a work memory used in a 32-bit microcomputer can be configured by using one 32-bit memory LSI.

  On the other hand, as the number of external terminals increases, the number of memory LSIs that can be mounted on a test evaluation board tends to decrease. The test efficiency of the memory LSI depends on the number of input / output terminals of the LSI tester. For example, if the number of input / output channels of the LSI tester is 256, a DRAM having an 8-bit input / output terminal can test 32 simultaneously, but a DRAM having a 32-bit input / output terminal can simultaneously test 8 Only one can be tested. As a result, the test cost (especially the test for shipping) is greatly increased.

  Recently, in order to prevent an increase in test cost due to an increase in the number of input / output terminals, a memory LSI having a data compression function for consolidating data signals in the memory LSI and efficiently performing a read / write operation test has been developed. .

  FIG. 12 shows a memory core 10 in an SDRAM (Synchronous DRAM) having a data compression function. This SDRAM has a 32-bit input / output terminal. Hereinafter, each bit of input / output data transmitted through the input / output terminal is also referred to as DQ.

  The memory core 10 has 96 memory cell arrays 12 arranged in 8 rows in the vertical direction and 12 columns in the horizontal direction.

  One row of the memory cell array 12 is assigned to one of the blocks BLK0 to BLK7. Blocks BLK0 and BLK4, blocks BLK1 and BLK5, blocks BLK2 and BLK6, and blocks BLK3 and BLK7 are simultaneously activated blocks. Twelve memory cell arrays 12 composed of 4 rows × 3 columns correspond to a predetermined DQ. In the figure, the memory cells with the symbol A correspond to DQ0, DQ1, DQ14, and DQ15. The memory cells with the symbol B correspond to DQ2, DQ3, DQ12, and DQ13. Memory cells marked with symbol C correspond to DQ4, DQ5, DQ10, and DQ11. The memory cells with the symbol D correspond to DQ6, DQ7, DQ8, and DQ9. The memory cells with the symbol E correspond to DQ18, DQ19, DQ28, and DQ29. The memory cells with the symbol F correspond to DQ16, DQ17, DQ30, and DQ31. The memory cells with the symbol G correspond to DQ22, DQ23, DQ24, and DQ25. The memory cells with the symbol H correspond to DQ20, DQ21, DQ26, and DQ27. A memory cell array region composed of twelve memory cell arrays 12 with symbols A to H is hereinafter also referred to as groups A to H.

  Column decoders 14 are arranged at the ends of the groups B, D, F, and H, respectively. A row decoder 16 is arranged between the groups C and D and the groups E and F. A word line WL is wired from the row decoder 16 toward the memory cell arrays 12 on both sides in the horizontal direction.

  Between the memory cell arrays 12, a plurality of main data line pairs MDLP are formed along the vertical direction, and a plurality of sub data line pairs are formed along the horizontal direction. The sub data line pair SDLP is connected to the main data line pair MDLP by a data line switch 18 indicated by a black circle. That is, the data line has a hierarchical structure. Group A, B, Group C, D, Group E, F, Group G, H have the same structure (including mirror symmetry), except for the DQ number. Therefore, the groups A and B will be mainly described below.

  FIG. 13 shows details of the layout of groups A and B.

  Each memory cell array 12 is formed with a plurality of bit line pairs BLP along the vertical direction. Adjacent bit line pairs BLP are wired with a bit line pair BLP of a different bit number sandwiched between them to avoid mutual interference. The bit line pair BLP is connected to the sub data line pair SDLP by a column line switch 20 indicated by a white circle. The bit line pair BLP connected to the column line switch 20 formed between the blocks (for example, between BLK1 and BLK2) is wired in both blocks (BLK1 and BLK2). The bit line pairs BLP connected to the column line switch 20 formed at the ends of the blocks BLK0 and BLK3 are wired in the blocks BLK0 and BLK3, respectively.

  Arrows indicated by bold lines in the figure indicate the flow of data in the read operation and the write operation. For example, data read from the memory cell array 12 of the group B block BLK1 is transmitted to the outside of the group B via the bit line pair BLP, the column line switch 20, the sub data line pair SDLP, the data line switch 18, and the main data line pair MDLP. (FIG. 13 (i)). Data written to the memory cell array 12 of the block BLK4 (group A) is from outside the group A via the main data line pair MDLP, the data line switch 18, the sub data line pair SDLP, the column line switch 20, and the bit line pair BLP. It is transmitted to a memory cell (not shown) (FIG. 13 (ii)).

  Each block (for example, BLK0 including groups B, D, F, and H shown in FIG. 12) has two word line relief circuits 22 respectively. The word line relief circuit 22 has a redundant word line (not shown) and a plurality of redundant memory cells (not shown) connected to the redundant word line. Each of the blocks BLK0 to BLK7 can relieve two word line defects or two bit defects by using the word line relief circuit 22.

  Each group A to H has at least one bit line relief circuit 24. The bit line relief circuit 24 has a redundant bit line pair (not shown) and a plurality of redundant memory cells (not shown) connected to the redundant bit line pair. The groups A to H can repair one bit line defect or one bit defect by using the bit line relief circuit 24.

  FIG. 14 shows a control circuit 26 formed between the blocks BLK0 and BLK1.

  The bit line pair BLP of the blocks BLK0 and BLK1 is connected to the shared bit line pair SHBLP via a bit line switch 28 made of an nMOS transistor. Each bit line switch 28 is controlled by control signals BT0 and BT1, which are activated according to the column address. A sense amplifier 30 and a precharge circuit 32 are connected to the shared bit line pair SHBLP. When the equalize signal BRS is at a high level, the precharge circuit 32 applies the precharge voltage VPR to the shared bit line pair SHBLP and the bit line pair BLP connected to the shared bit line pair SHBLP by the control signals BT0 and BT1. Is a circuit for supplying The sense amplifier 30 and the precharge circuit 32 are shared by the blocks BLK0 and BLK1 through the bit line switch 28. The shared bit line pair SHBLP is connected to the sub data line pair SDLP via a column line switch 20 made of an nMOS transistor. The gate of the column line switch 20 is controlled by a column line selection signal CL that is activated according to a column address. The data line switch 18 for connecting the sub data line pair SDLP and the main data line pair MDLP is composed of an nMOS transistor and an inverter. The gate of the data line switch 18 is controlled by a precharge signal BRS via an inverter. For example, in the read operation of block BLK0, control signal BT0 and column line selection signal CL change to high level, control signal BT1 and precharge signal BRS change to low level, bit line pair BLP of block BLK0, shared bit This is executed by connecting the line pair SHBLP, the sub data line pair SDLP, and the main data line pair MDLP.

  FIG. 15 shows a control circuit 34 formed between the blocks BLK3 and BLK4 (between groups A and B).

  Since groups A and B have different bit numbers (DQ) of data to be held, each group has a control circuit. The bit line switch 28 connected to the end of the shared bit line pair SHBLP has a gate connected to the ground line VSS and an end opposite to the bit line pair BLP open. In block BLK3, precharge circuit 32 and data line switch 18 receive precharge signal BRS3, column line switch 20 receives column line selection signal CL, and switch 28 connected to bit line pair BLP receives control signal. Received BT3. In block BLK4, precharge circuit 32 and data line switch 18 receive precharge signal BRS4, column line switch 20 receives column line selection signal CL, and bit line switch 28 connected to bit line pair BLP Receives control signal BT4.

  As described above, the sense amplifier 30, the precharge circuit 32, and the like corresponding to the groups A and B are arranged at the boundary between the groups A and B, respectively. For this reason, a larger layout area is required between the blocks BLK3 and BLK4 than between the other blocks.

  FIG. 16 shows a data compression circuit 36 for write data in a conventional SDRAM.

  The data compression circuit 36 includes eight buffer circuits 38 and selection circuits 40 corresponding to the input / output data signals DQ0 to DQ7. The buffer circuit 38 receives the input / output data signals DQ0 to DQ7, and outputs them as write data signals DINCZ0 to DINCZ7. The selection circuit 40 receives the write data signals DINCZ0 to DINCZ7 and the compression test enable signal TEST8 and outputs write data signals DIN0 to DIN7.

  FIG. 17 shows details of the selection circuit 40.

  The selection circuit 40 includes eight switch circuits 42 corresponding to the write data signals DINCZ0 to DINCZ7, and inverters 40a, 40b, and 40c that control the switch circuits 42, respectively. The switch circuit 42 includes a CMOS transmission gate 42a that transmits a signal supplied to the terminal D1 via an inverter, and a CMOS transmission gate 42b that transmits a signal supplied to the terminal D2. The outputs of the CMOS transmission gates 42a and 42b are connected to each other and connected to the terminal DO via two cascaded inverters. The CMOS transmission gates 42a and 42b are controlled by a signal in phase with the enable signal TEST8 and a signal in reverse phase.

  The CMOS transmission gate 42a is turned on when the enable signal TEST8 is at a low level (normal operation). The CMOS transmission gate 42b is turned on when the enable signal TEST8 is at a high level (data compression test). The terminal D2 of each selection circuit 42 receives an inverted signal of the write data signal DINCZ7 via the inverter 40c. That is, in normal operation, write data signals DINCZ0-7 are transmitted as write data signals DIN0-7, respectively. In the operation of the data compression test, the 8-bit input / output terminal is compressed to 1 bit, and the write data signal DINCZ7 is transmitted as the write data signals DIN0 to DIN7. Although not particularly shown, the selection circuit 40 having the same structure is also formed for the input / output data signals DQ8-15, DQ16-23, and DQ24-31.

  The evaluation board of the LSI tester that evaluates the SDRAM can execute a read / write operation test of one SDRAM only by using a 4-bit (DQ7, DQ15, DQ23, DQ31) input / output channel. For example, an LSI tester having 256 input / output channels can execute 64 SDRAM tests at a time.

The data compression test is often performed in order to confirm the operation of the chip in a probe test (repair determination) in a wafer state and a final test after being assembled into a package.
JP-A-6-333400

  By the way, in the data compression test, since input / output data is collected and tested, even if a defect is found in the test, it cannot be determined which bit of the input / output data is defective. For example, as indicated by the crosses in FIG. 13, even when there is a bit defect in DQ2 of block BLK0 and a word line defect occurs, the defect is detected in groups A, B, C in the data compression test. , D cannot be determined. Therefore, when this defect is repaired using the word line repair circuit 22, both the word line repair circuits 22 of the blocks BLK0 and BLK4 must be used. In other words, the relief efficiency (usage efficiency of the word line relief circuit 22) is lowered because the normally operating word line in the block BLK4 is relieved. As a result, there is a problem in that the yield decreases and the manufacturing cost increases.

  The relief address and relief DQ can be confirmed by a normal read / write operation test without using the data compression test method. However, in this case, since the number of memory LSIs that can be tested simultaneously by the LSI tester is reduced (in the above example, 64 to 8), the manufacturing cost (test cost) is greatly increased.

  Furthermore, a reduction in repair efficiency can be prevented by adding a data compression test control circuit corresponding to the number of DQs (4 bits in the above example) of each memory cell array 12 and changing the number of bits to be compressed. However, in this case, a new selection circuit must be formed in addition to the selection circuit shown in FIG. As a result, a large layout area is required, and the chip size may increase.

  Further, since the sense amplifier 30 and the precharge circuit 32 are arranged for each block BLK3 and BLK4 between the blocks BLK3 and BLK4 shown in FIG. 15, unlike the other blocks, the layout area becomes large. was there.

  An object of the present invention is to reduce the chip size of a semiconductor integrated circuit. For example, it is to reduce the chip size of a semiconductor integrated circuit having a data compression test function.

  In one embodiment of the present invention, a semiconductor integrated circuit includes a plurality of input / output terminals that transmit input / output data, a plurality of memory cell array regions, a bit line switch corresponding to each memory cell array region, and a sense amplifier. Yes. Each memory cell array region is assigned different numbers of bits of input / output data, and different addresses are assigned. The bit line switch connects a plurality of bit lines respectively connected to the memory cells in each memory cell array region to a shared bit line formed in the memory cell array region. The sense amplifier is connected to the shared bit line and amplifies the bit line data transmitted via the bit line switch. For example, when a certain memory cell array area is accessed, only the bit line switch corresponding to that memory cell array is turned on, and a predetermined bit of input / output data is transmitted between the bit line and the shared bit line. The The sense amplifier amplifies data transmitted to the shared bit line. When another memory cell array area is accessed, only the bit line switch corresponding to that memory cell array area is turned on, and the bit data different from the previous one of the input / output data is transmitted between the bit line and the shared bit line. Is done. The sense amplifier amplifies different bit data transmitted to the shared bit line from the previous time. Thus, the sense amplifier is shared for input / output data of different bits. As a result, the number of sense amplifiers can be reduced, the layout area of the memory cell array region is reduced, and the chip size is reduced.

  In a preferred example of one aspect of the present invention, the semiconductor integrated circuit includes a data line switch that connects the shared bit line and a data line corresponding to a bit assigned to each memory cell array region. Therefore, data of a predetermined bit assigned to the memory cell array is reliably transmitted between the memory cell array region and the data line.

  In a preferred example of one embodiment of the present invention, two memory cell array regions are connected to the shared bit line via each bit line switch. The control signal for the bit line switch corresponding to the bit in one memory cell array region is used as a control signal for deactivating the data line switch corresponding to the bit in the other memory cell array. That is, when the bit line in one memory cell array region is activated, the bit line in the other memory cell array region is deactivated. Therefore, the data line switches corresponding to the two memory cell array regions can be easily controlled without forming a special signal generation circuit.

  In a preferred example of one embodiment of the present invention, the semiconductor integrated circuit has a test mode in which a plurality of bit line switches are simultaneously turned on and input / output data is collectively written in each memory cell array region. At least one of the data line switches is turned on in the test mode. Therefore, by using one data line, input / output data can be written to the memory cell array region corresponding to the other data line. That is, the data compression test can be easily executed.

  In a preferred example of an embodiment of the present invention, by simultaneously turning on a plurality of bit line switches, all word lines connected to the memory cells are activated, and a burn-in test that applies stress to these memory cells is executed. .

  In the present invention, sense amplifiers can be shared for input / output data of different bits, and the number of sense amplifiers can be reduced. As a result, the layout area of the memory cell array region can be reduced, and the chip size can be reduced.

  Data of a predetermined bit assigned to the memory cell array region can be reliably transmitted between the memory cell array region and the data line.

  Data line switches corresponding to the two memory cell array regions can be easily controlled without forming a special signal generation circuit.

  By using one data line, input / output data can be written to the memory cell array region corresponding to the other data line. That is, the data compression test can be easily executed.

  When performing a wafer burn-in test, write data can be compressed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a memory core in a first embodiment of a semiconductor integrated circuit according to the present invention. The same circuits as those of the prior art are denoted by the same reference numerals, and detailed description of these circuits is omitted.

  The semiconductor integrated circuit is formed as an SDRAM having a data compression function on a silicon substrate using a CMOS process technology. The SDRAM has a 32-bit input / output terminal for transmitting input / output data.

  The SDRAM memory core 50 has 96 memory cell arrays 12 arranged in 8 rows in the vertical direction and 12 columns in the horizontal direction. The memory cell array 12 has a plurality of memory cells. Although not particularly shown, a write amplifier for writing data, a sense buffer for reading data, and the like are formed around the memory core 50.

  One row of the memory cell array 12 is assigned to one of the blocks BLK0 to BLK7. Blocks BLK0 and BLK4, blocks BLK1 and BLK5, blocks BLK2 and BLK6, and blocks BLK3 and BLK7 are simultaneously activated blocks. For example, when a certain address is supplied from the outside, the blocks BLK0 and BLK4 are activated simultaneously. Twelve memory cell arrays 12 composed of 4 rows × 3 columns correspond to a predetermined DQ. The memory cell array region composed of these memory cell arrays 12 is referred to as group A to group H as in the prior art.

  Column decoders 14 are arranged at the ends of the groups B, D, F, and H, respectively. A row decoder 16 is arranged between the groups C and D and the groups E and F. A word line WL is wired from the row decoder 16 to the memory cell arrays 12 on both sides in the horizontal direction.

  Between the memory cell arrays 12, a plurality of main data line pairs MDLP are formed along the vertical direction, and a plurality of sub data line pairs SDLP are formed along the horizontal direction. The sub data line pair SDLP is connected to the main data line pair MDLP by a data line switch 18 indicated by a black circle. That is, the data line has a hierarchical structure.

  Between the blocks BLK3 and BLK4, a sub data line pair SDLP in which the data line switch 18 corresponding to the upper group and the data line switch 18 corresponding to the lower group are connected is formed.

  FIG. 2 shows details of the layout of groups A and B. Here, only elements different from FIG. 13 described in the related art will be described. As in the prior art, each block (for example, BLK0 composed of groups B, D, F, and H shown in FIG. 1) has two word line relief circuits 22, and each group A to H has at least one bit line relief circuit 24.

  The bit line pair BLP of the blocks BLK3 and BLK4 is connected to a sub data line pair SDLP formed between the blocks BLK3 and BLK4 by a column line switch 20 indicated by white circles. That is, the sub data line pair SDLP formed between the blocks BLK3 and BLK4 is used for DQ2 and DQ3 when the block BLK3 operates, and is used for DQ0 and DQ1 when the block BLK4 operates.

  Note that the data line is not limited to the structure formed between the blocks, and may be, for example, a structure wired over the memory cell array.

  FIG. 3 shows a control circuit 52 formed between the blocks BLK3 and BLK4. Note that the same control circuit 26 as in the prior art (FIG. 14) is formed between the other blocks.

  The bit line pair BLP of the blocks BLK3 and BLK4 is connected to the shared bit line pair SHBLP via a bit line switch 28 made of an nMOS transistor. Each bit line switch 28 is controlled by control signals BT3 and BT4 which are activated according to the column address. That is, the control signal BT3 is an activation signal that activates the bit line pair BLP of the block BLK3, and the control signal BT4 is an activation signal that activates the bit line pair BLP of the block BLK4. A sense amplifier 30 and a precharge circuit 32 are connected to the shared bit line pair SHBLP. The sense amplifier 30 and the precharge circuit 32 are shared by the blocks BLK3 and BLK4 via the bit line switch 28. For this reason, the layout area of the control circuit 52 is significantly reduced as compared with the conventional control circuit 34 (FIG. 15).

  The shared bit line pair SHBLP is connected to the sub data line pair SDLP via a column line switch 20 made of an nMOS transistor. The gate of the column line switch 20 is controlled by a column line selection signal CL that is activated according to a column address. In order to connect the sub data line pair SDLP and the two main data line pairs MDLP, two data line switches 18 are formed. The gate of the data line switch 18 corresponding to the group A is controlled by a control signal BT3 for controlling the block BLK3 (group B) through an inverter. The gate of the data line switch 18 corresponding to the group B is controlled by a control signal BT4 that controls the block BLK4 (group A) via an inverter. In other words, the control signal BT3 activates the bit line switch 28 of the block BLK3 and simultaneously deactivates the data line switch 18 corresponding to the block BLK4. The control signal BT4 activates the bit line switch 28 of the block BLK4 and simultaneously deactivates the data line switch 18 corresponding to the block BLK3. Since the gate of the data line switch 18 is controlled by the inverted signals of the control signals BT3 and BT4 of the counterpart block, the control circuit is simplified.

  For example, in the read operation of block BLK3, control signal BT3 and column line selection signal CL change to high level, control signal BT4 and precharge signal BRS change to low level, bit line pair BLP of block BLK3, shared bit This is executed by connecting the line pair SHBLP, the shared sub data line pair SDLP, and the main data line pair MDLP corresponding to the group B.

  FIG. 4 shows a data compression circuit 54 for write data. The data compression circuit 54 has eight buffer circuits 38 and selection circuits 56 corresponding to the input / output data signals DQ0 to DQ7. The selection circuit 56 receives write data signals DINCZ0 to DINCZ7 and data compression test enable signals TEST4 and TEST8, and outputs write data signals DIN0 to DIN7. The enable signal TEST4 is at a high level during a 4-bit data compression test, and the enable signal TEST8 is at a high level during an 8-bit data compression test. That is, the SDRAM of this embodiment has two types of compression test modes that can reduce the number of input / output data bits (number of input / output terminals) to one-fourth or one-eighth.

  FIG. 5 shows details of the selection circuit 56. The selection circuit 56 includes eight (1 byte) switch circuits 42 corresponding to the write data signals DINCZ0 to DINCZ7, an OR circuit 56a for controlling these switch circuits 42, an inverter 56b, and write data signals DIN0, DIN1, And a switch circuit 58 for selecting a data signal to be supplied to the switch circuit 42 corresponding to DIN4 and DIN5. The switch circuit 42 corresponds to the second switch circuit, and the switch circuit 58 corresponds to the first switch circuit. The switch circuit 58 is composed of two CMOS transmission gates and two inverters. The switch circuit 58 is a circuit that outputs an inverted signal of the write data signal DINCZ0 when the enable signal TEST4 is at a high level and outputs an inverted signal of the write data signal DINCZ7 when the enable signal TEST4 is at a low level.

  The CMOS transmission gates 42a and 42b of the switch circuit 42 are controlled by a signal in phase with the OR logic of the enable signals TEST4 and TEST8 and a signal in reverse phase. The CMOS transmission gate 42a is turned on when the enable signals TEST4 and TEST8 are both at a low level (normal operation). The CMOS transmission gate 42b is turned on when one of the enable signals TEST4 and TEST8 is at a high level (a 4-bit data compression test or an 8-bit data compression test). The terminal D2 of the selection circuit 42 corresponding to the write data signals DIN0, DIN1, DIN4, and DIN5 receives the write data signal DINCZ0 or the inverted signal of the write data signal DINCZ7 via the switch circuit 58. The terminal D2 of the selection circuit 42 corresponding to the write data signals DIN2, DIN3, DIN6, and DIN7 receives an inverted signal of the write data signal DINCZ7 through the inverter 56b.

  As described above, in this embodiment, a plurality of data compression tests can be performed using the same switch circuit 42 as in the past. This is because the selection circuit 56 is configured by the two-stage switch circuits 42 and 58. That is, the switch circuit 42 selects either normal data or test data, and the switch circuit 58 formed before the switch circuit 42 is one of a plurality of test data (write data signals DINCZ0 and DINCZ7). Select. Since the load of the write data signals DIN0 to DIN7 can be made the same as before, the timing design becomes easy. Further, a plurality of test data is selected by a simple switch circuit 58 constituted by a CMOS transmission gate. Therefore, a control circuit for a data compression test can be formed with a minimum layout area.

  Next, the operation of the selection circuit 56 will be described. In the normal operation mode, write data signals DINCZ0-7 are transmitted as write data signals DIN0-7, respectively. In the operation of the 4-bit data compression test, the 4-bit input / output terminal is compressed to 1 bit, and the write data signals DINCZ0 and DINCZ7 are written data signals DIN0, DIN1, DIN4, DIN5 and write data signals DIN2, DIN3, It is transmitted as DIN6 and DIN7. In the operation of the 8-bit data compression test, the 8-bit input / output terminal is compressed to 1 bit, and the write data signal DINCZ7 is transmitted as all the write data signals DIN0-7. Although not particularly shown, the input / output data signals DQ8-15, DQ16-23, and DQ24-31 are also controlled by the same selection circuit 56.

  The evaluation board of the LSI tester that evaluates this SDRAM is 4 bits (DQ7, DQ15, DQ23, DQ31) or 8 bits (DQ0, DQ7, DQ8, DQ15, DQ16, DQ23, DQ23, DQ24, DQ31) SDRAM read / write operation test can be executed simply by using the I / O channel. For example, by applying a 4-bit data compression test to a defect remedy test (test in a wafer state), it is possible to remedy the defect by using only the word line relief circuit 22 of the block in which the defect actually occurs. Therefore, even when the data compression test is applied to the relief determination, the number of SDRAMs to be simultaneously measured by the LSI tester can be increased without reducing the relief efficiency (use efficiency of the word line relief circuit 22). . In order to improve the repair efficiency, it is necessary to limit the defects confirmed in the data compression test within one block (for example, BLK0) which is the minimum unit of the word line repair circuit 22.

  By applying the 8-bit data compression test to the final test after assembly, the cost of the final test can be reduced. Further, when measuring electrical characteristics such as access speed and current consumption, the normal operation mode can be used. Thus, the most efficient test method can be selected and executed according to the test process. Further, since the sense amplifier 30 and the precharge circuit 32 used in the blocks BLK3 and BLK4 having different DQ numbers are shared, the layout area of the control circuit 52 can be greatly reduced as compared with the conventional case.

  FIG. 6 shows a data compression circuit 60 in the second embodiment of the semiconductor integrated circuit of the present invention. The same circuits as those in the first embodiment are denoted by the same reference numerals, and detailed description of these circuits is omitted. The SDRAM of this embodiment has a 16-bit input / output terminal.

  The data compression circuit 60 is a circuit in which two data compression circuits 54 of the first embodiment are combined. The data compression circuit 60 includes 16 buffer circuits 38 corresponding to the input / output data signals DQ0 to DQ15, two selection circuits 62, and a buffer circuit 38 that transmits a write data signal DIN that is test data. is doing. The selection circuit 62 corresponding to the input / output data signals DQ0 to DQ7 receives the write data signals DINCZ0 to DINCZ7, the data compression test enable signals TEST4, TEST8 and TEST, and the write data signal DIN, and outputs the write data signals DIN0 to DIN7. is doing. The selection circuit 62 corresponding to the input / output data signals DQ8 to DQ15 receives the write data signals DINCZ8 to DINCZ15, the data compression test enable signals TEST4, TEST8 and TEST, and the write data signal DIN, and outputs the write data signals DIN8 to DIN15. is doing. The enable signal TEST4 is high during a 4-bit data compression test, the enable signal TEST8 is high during an 8-bit data compression test, and the enable signal TEST is a 16-bit data compression test. Sometimes it becomes a high level. That is, the SDRAM of this embodiment has three types of data compression test functions. Other configurations are the same as those of the first embodiment except that the input / output terminals are 16 bits. Since the input / output terminals are 16 bits, for example, in the memory core 50 shown in FIG. 1, DQ6 to DQ31 of groups E, F, G, and H correspond to addresses different from those of groups A, B, C, and D. is doing.

  FIG. 7 shows details of the selection circuit 62 corresponding to the input / output data signals DQ0 to DQ7. The signal names of the selection circuit 62 corresponding to the input / output data signals DQ8 to DQ15 are shown in parentheses.

  The selection circuit 62 includes eight switch circuits 42 corresponding to the write data signals DINCZ0 to DINCZ7, an OR circuit 62a for controlling these switch circuits 42, a switch circuit 63 including transmission circuits 62b, 62c, and 62d, The latch circuit 62e includes a switch circuit 64 that selects a data signal to be supplied to the switch circuit 42 corresponding to the write data signals DIN2, DIN3, DIN6, and DIN7. The switch circuits 63 and 64 correspond to the first switch circuit.

  The transmission circuits 62b, 62c, and 62d are composed of a CMOS transmission gate and an inverter that controls the transmission gate. The transmission circuit 62b is turned on when the enable signal TEST4 is at a high level, and transmits the write data signal DINCZ0 to the latch circuit 62e. The transmission circuit 62c is turned on when the enable signal TEST8 is at a high level, and transmits the write data signal DINCZ7 to the latch circuit 62e. The transmission circuit 62d is turned on when the enable signal TEST is at a high level, and transmits the write data signal DIN (DQ8) to the latch circuit 62e. The latch 62e is configured by connecting the inputs and outputs of the two inverters 62f and 62g to each other. The inverter 62g of the latch circuit 62e prevents a through current from being generated in the inverter 62f. That is, when the latch 62e is composed of only the inverter 62f, when the outputs of the transmission circuits 62b, 62c and 62d of the switch circuit 63 are high impedance, the input of the inverter 62f becomes indefinite. The inverter 62g eliminates this indefinite state.

  The switch circuit 64 is composed of two CMOS transmission gates and an inverter. The switch circuit 64 is a circuit that outputs an inverted signal of the write data signal DIN when the enable signal TEST is high and outputs an inverted signal of the write data signal DINCZ7 when the enable signal TEST is low.

  The CMOS transmission gate (not shown) of the switch circuit 42 is controlled by a signal in phase with the OR logic of the enable signals TEST4, TEST8, and TEST and a signal in reverse phase. That is, the switch circuit 42 outputs the signal received at the terminal D1 from the terminal DO when the enable signals TEST4, TEST8, and TEST are all at a low level (normal operation). The switch circuit 42 is connected to the terminal D2 when any of the enable signals TEST4, TEST8, and TEST is at a high level (a 4-bit data compression test, an 8-bit data compression test, or a 16-bit data compression test). The received signal is output from terminal DO. The terminal D2 of the selection circuit 42 corresponding to the write data signals DIN0, DIN1, DIN4, and DIN5 receives any of the inverted signals of the write data signals DINCZ0, DINCZ7, and DIN (DQ8) via the latch 62e. The terminal D2 of the selection circuit 42 corresponding to the write data signals DIN2, DIN3, DIN6, and DIN7 receives an inverted signal of the write data signal DINCZ7 or an inverted signal of the write data signal DIN via the switch circuit 64. That is, in normal operation, write data signals DINCZ0-7 are transmitted as write data signals DIN0-7, respectively.

  In the operation of the 4-bit data compression test, 4-bit input / output data is compressed to 1 bit. The inverted signal of the write data signal DINCZ0 and the inverted signal of DINCZ7 are the write data signals DIN0, DIN1, DIN4, DIN5 and write, respectively. It is transmitted as data signals DIN2, DIN3, DIN6 and DIN7. At this time, in the selection circuit 62 corresponding to the input / output data signals DQ8 to DQ15, the inverted signal of the write data signal DINCZ8 and the inverted signal of DINCZ15 are the write data signals DIN8, DIN9, DIN12, DIN13 and the write data signals DIN10, DIN11, respectively. , DIN14 and DIN15. The 4-bit data compression test is used for relief determination and the like, as in the first embodiment.

  In the operation of the 8-bit data compression test, 8-bit input / output data is compressed to 1 bit, and an inverted signal of the write data signal DINCZ7 is transmitted as write data signals DIN0-7. At this time, in the selection circuit 62 corresponding to the input / output data signals DQ8 to DQ15, the inverted signal of the write data signal DINCZ15 is transmitted as the write data signals DIN8 to DIN15. The 8-bit data compression test is used in the final test after assembly.

  In the operation of the 16-bit data compression test, 16-bit input / output data is compressed to 1 bit, and the write data signal DIN (DQ8) is transmitted as the write data signals DIN0-7. At this time, also in the selection circuit 62 corresponding to the input / output data signals DQ8 to DQ15, the write data signal DIN (DQ8) is transmitted as the write data signals DIN8 to DIN15. The 16-bit data compression test is used in the wafer burn-in test described later.

  Here, each selection circuit 62 is supplied with the write data signal DIN output from the buffer circuit 38 dedicated to the test, not the write data signal DINCZ8 used in the normal operation. For this reason, the load of the write data signal DINCZ8 is the same as the other write data signals DINCZ0 to 7 and 9 to 15. During normal operation, the write timing is not delayed by the write data signal DINCZ8.

  FIG. 8 shows a control circuit 66 formed between the blocks BLK3 and BLK4. In the control circuit 66, the NAND gate controls the gate of the data line switch 18a corresponding to DQ0, DQ1, DQ14, and DQ15. Other configurations of the control circuit 66 are the same as those of the control circuit 52 shown in FIG. The NAND gate receives the control signal BT3 at one input and the test mode signal WBIX at the other input. The test mode signal WBIX is a signal activated (low level) during the wafer burn-in test. In this embodiment, the wafer burn-in test is performed using a 16-bit data compression test mode with the maximum compression efficiency. The wafer burn-in test is a test in which a plurality of SDRAMs on a wafer are burned in at once. In the wafer burn-in test, a high voltage can be directly applied to a word line or the like using a test pad on a chip, so that many SDRAMs can be screened in a short time.

  In the wafer burn-in test, since all the memory cells on the chip are selected, the control signals BT3 and BT4 are all at a high level. At this time, the data line switch 18 is turned off. The write data is transmitted to the memory cell via the data line switch 18a which is turned on in response to the low level of the test mode signal WBIX data. That is, the wafer burn-in test is executed using the data compression test mode.

  Also in this embodiment, the same effect as that of the first embodiment described above can be obtained. Further, in this embodiment, a latch circuit 62e for latching test data is provided between the switch circuit 63 and the switch circuit 42. For this reason, when the outputs of the transmission circuits 62b, 62c, and 62d of the switch circuit 63 are high impedance, it is possible to prevent the input of the inverter 62f from becoming indefinite, and it is possible to prevent a through current from being generated in the inverter 62f.

  A dedicated buffer circuit 38 is provided which receives the input / output data signal DQ8 and supplies the received signal to the switch circuits 62d and 64 as a write data signal DIN. For this reason, all the loads of the write data signals DINCZ0 to DINCZ15 supplied to the switch circuit 42 can be made the same. As a result, the supply timing of the specific bit (DQ8) used in the data compression test mode to the switch circuit 42 can be prevented from shifting.

  The logic of the test mode signal WBIX is added to the control of the data line switch 18a, and the data line switch 18a is turned on during the wafer burn-in test. Therefore, by using one main data line pair MDLP, input / output data can be written to a block corresponding to the other main data line pair MDLP. That is, the write data can be compressed when performing the wafer burn-in test. As a result, in the burn-in test, the number of probes connected to the pads on the chip for supplying write data can be minimized.

  FIG. 9 shows a third embodiment of the semiconductor integrated circuit of the present invention. The same circuits as those in the first embodiment are denoted by the same reference numerals, and detailed description of these circuits is omitted. In this embodiment, the control circuit 68 is configured by adding nMOS transistors 68 a and 68 b to the control circuit 52 of the first embodiment. The nMOS transistors 68a and 68b are turned on in response to the high-level test mode signal WBIZ, and have a function of connecting the main data line pair MDLP to the sub data line pair SDLP. The test mode signal WBIZ is a signal activated (high level) during the wafer burn-in test.

  Also in this embodiment, the same effects as those of the second embodiment described above can be obtained. Further, in this embodiment, since the control circuit 68 is configured by adding an nMOS transistor, the layout area between the blocks BLK3 and BLK4 can be reduced.

  In the first embodiment described above, the example in which the switch circuit 42 is constituted by a CMOS transmission gate as shown in FIG. 5 has been described. The present invention is not limited to such an embodiment. For example, as shown in FIG. 10, the switch circuit 70 may be configured with a clocked inverter. Alternatively, as shown in FIG. 11, a switch circuit 72a having a clocked inverter and a switch circuit 72b having an inverter using the power source of the switch circuit 72a may be formed. The switch circuit 72a outputs voltages VD1, VS1, VD2, and VS1 from the drains of the pMOS transistor and the nMOS transistor on the power supply side in the clocked inverter, respectively. The switch circuit 72b receives these voltages VD1, VS1, VD2, and VS1 at the sources of the pMOS transistor and the nMOS transistor, respectively. This eliminates the need for control pMOS transistors and nMOS transistors in the switch circuit 72b.

  In the first embodiment described above, the example in which the data line switch 18 is configured by an nMOS transmission gate has been described. The present invention is not limited to such an embodiment. If the layout area is sufficient, the data line switch 18 may be constituted by a CMOS transmission gate.

In the first embodiment described above, the write data DINCZ0 is used during the data compression test.
An example using DINCZ7 was described. The present invention is not limited to such an embodiment. The bits used for the write data may be arbitrarily determined.

  In the second embodiment described above, the example in which the main data line pair MDLP corresponding to DQ0, DQ1, DQ14, and DQ15 is connected to the sub data line pair SDLP via the data line switch 18a has been described. The present invention is not limited to such an embodiment. For example, the main data line pair MDLP corresponding to DQ2, DQ3, DQ12, DQ13 may be connected to the sub data line pair SDLP via the data line switch 18a, and DQ0, DQ1, DQ14, DQ15, and DQ2, DQ3, The main data line pair MDLP corresponding to DQ12 and DQ13 may be connected to the sub data line pair SDLP via the data line switch 18a, respectively.

  In the second embodiment described above, an example in which the input and output of two inverters are connected to form the latch circuit 62e has been described (FIG. 7). The present invention is not limited to such an embodiment. For example, even if one inverter is replaced with a NAND gate, a power-on reset signal that is activated (low level) at power-on or a control signal including the logic of the power-on reset signal is supplied to one input of the NAND gate. Good. As a result, the NAND gate operates as a reset circuit, and the latch circuit is reliably initialized at power-on. Moreover, generation of a through current can be prevented.

  In the second embodiment described above, the example in which the present invention is applied to the wafer burn-in test has been described. The present invention is not limited to such an embodiment. For example, it may be applied to SDRAM burn-in test after assembly.

  In the third embodiment described above, the example in which the main data line pair MDLP corresponding to DQ0, DQ1, DQ14, and DQ15 is connected to the sub data line pair SDLP via the nMOS transistors 68a and 68b has been described. The present invention is not limited to such an embodiment. For example, the main data line pair MDLP corresponding to DQ2, DQ3, DQ12, DQ13 may be connected to the sub data line pair SDLP via nMOS transistors 68a, 68b, and DQ0, DQ1, DQ14, DQ15, and DQ2, DQ3 The main data line pair MDLP corresponding to DQ12 and DQ13 may be connected to the sub data line pair SDLP via nMOS transistors 68a and 68b, respectively.

  In the above-described embodiment, the example in which the present invention is applied to the SDRAM having 16 or 32 input / output terminals has been described. The present invention is not limited to such an embodiment. For example, the present invention may be applied to an SDRAM having 64 or more input / output terminals.

  In the above-described embodiment, the example in which the present invention is applied to the SDRAM has been described. However, the present invention is not limited to such an embodiment. For example, the present invention may be applied to a normal clock asynchronous asynchronous DRAM or SRAM. Alternatively, the present invention may be applied to a system LSI incorporating a DRAM memory core.

  The semiconductor manufacturing process to which the present invention is applied is not limited to a CMOS process, and may be a Bi-CMOS process.

  As mentioned above, although this invention was demonstrated in detail, said embodiment and its modification are only examples of this invention, and this invention is not limited to this. Obviously, modifications can be made without departing from the scope of the present invention.

FIG. 3 is a layout diagram illustrating a memory core according to the first embodiment. FIG. 2 is a layout diagram illustrating details of a main part of FIG. 1. It is a circuit diagram which shows the control circuit formed between blocks. It is a block diagram which shows the data compression circuit in 1st Embodiment. FIG. 5 is a circuit diagram showing details of the selection circuit of FIG. 4. It is a block diagram which shows the data compression circuit in 2nd Embodiment. FIG. 7 is a circuit diagram showing details of the selection circuit of FIG. 6. It is a circuit diagram which shows the control circuit formed between the blocks in 2nd Embodiment. It is a circuit diagram which shows the control circuit formed between the blocks in 3rd Embodiment. It is a circuit diagram which shows another example of a selection circuit. It is a circuit diagram which shows another example of a selection circuit. It is a layout diagram showing a memory core of a conventional SDRAM. FIG. 12 is a layout diagram illustrating details of a main part of FIG. 11. It is a circuit diagram which shows the control circuit formed between the blocks in the conventional SDRAM. It is a circuit diagram which shows the control circuit formed between another block in the conventional SDRAM. It is a block diagram which shows the data compression circuit in the conventional SDRAM. FIG. 17 is a circuit diagram showing details of the selection circuit of FIG. 16.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 Memory cell array 14 Column decoder 16 Row decoder 18 Data line switch 18a Data line switch 20 Column line switch 22 Word line relief circuit 24 Bit line relief circuit 26 Control circuit 28 Bit line switch 30 Sense amplifier 32 Precharge circuit 38 Buffer circuit 42 Switch Circuit 42a, 42b CMOS transmission gate 50 Memory core 52 Control circuit 54 Data compression circuit 56 Selection circuit 56a OR circuit 56b Inverter 58 Switch circuit 60 Data compression circuit 62 Selection circuit 62a OR circuit 62b, 62c, 62d Transmission circuit 62e Latch circuit 63 Switch Circuit 64 Switch circuit 66 Control circuit 68 Control circuit 68a, 68b nMOS transistor 70 Switch circuit 72a, 72b Switch circuit
BLK0 ~ BLK7 block
BLP bit line pair
BRS precharge signal
BT3, BT4 control signal
CL Column line selection signal
DIN0 to DIN7 Write data signal
DINCZ0 to DINCZ7 Write data signal
DQ0 to DQ7 I / O data signal
MDLP main data line pair
SDLP secondary data line pair
SHBLP Shared bit line pair
TEST4, TEST8, TEST enable signal
WBIX, WBIZ test mode signal
WL word line

Claims (5)

A plurality of input / output terminals for transmitting input / output data;
A plurality of memory cell array regions to which different numbers of bits of the input / output data are assigned and different addresses are assigned,
A plurality of bit lines respectively connected to the memory cells in each memory cell array region, bit line switches respectively connecting to the shared bit lines formed in the memory cell array region;
A semiconductor integrated circuit, comprising: a sense amplifier connected to the shared bit line and amplifying data of the bit line transmitted through the bit line switch. The semiconductor integrated circuit according to claim 1,
A semiconductor integrated circuit comprising a data line switch for connecting the shared bit line and a data line corresponding to the bit assigned to each memory cell array region. The semiconductor integrated circuit according to claim 2.
The shared bit line is connected to two memory cell array regions via the bit line switches,
The control signal for the bit line switch corresponding to the bit in one memory cell array region is used as a control signal for deactivating the data line switch corresponding to the bit in the other memory cell array region. A semiconductor integrated circuit. The semiconductor integrated circuit according to claim 1,
A test mode in which a plurality of the bit line switches are simultaneously turned on, and the input / output data is collectively written in the memory cell array regions;
At least one of the data line switches is turned on in the test mode. The semiconductor integrated circuit according to claim 1,
The test mode is a burn-in test mode in which all word lines connected to the memory cell are activated and stress is applied to the memory cell.

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