Abstract:
A method for testing a memory device includes entering a test mode in which multiple memory banks operate in a same manner, allowing a row corresponding to a row address in the multiple memory banks to be activated, latching a bank address and the row address corresponding to the multiple memory banks, writing same data in a column selected by a column address in the multiple memory banks, reading the data written in the writing of the data from the multiple memory banks, checking whether the data read from the multiple memory banks in the reading of the data are equal to each other, and programming the row address to locations designated by the bank address latched in the latching in a nonvolatile memory when the data read from the multiple memory banks are different from each other.

Description:
BACKGROUND 
       [0001]    1. Field 
         [0002]    Exemplary embodiments of the present invention relate to a memory device and a test method thereof. 
         [0003]    2. Description of the Related Art 
         [0004]    Most memory device such as DRAM (Dynamic Random Access Memory) has a repair scheme for repairing failures therein. 
         [0005]      FIG. 1  is a block diagram illustrating a conventional memory device including a row repair scheme. 
         [0006]    Referring to  FIG. 1 , the memory device includes a cell array  110  including a plurality of memory cells, a row circuit  120  for activating a word line selected by a row address R_ADD, and a column circuit for accessing a bit line selected by a column address C_ADD for reading or writing. 
         [0007]    A row fuse circuit  140  stores a row address corresponding to a failed memory cell in the cell array  110 , as a repair row address REPAIR_R_ADD. A row comparison unit  150  compares the repair row address REPAIR_R_ADD stored in the row fuse circuit  140  with the row address R_ADD input from an external source. When the repair row address REPAIR_R_ADD coincides with the row address R_ADD, the row comparison unit  150  controls the row circuit  120  to activate a redundant word line instead of the word line designated by the row address R_ADD. That is, the word line corresponding to the repair row address REPAIR_R_ADD stored in the row fuse circuit  140  is replaced with the redundant word line. 
         [0008]    A signal RACT in  FIG. 1  indicates that an active command for allowing a word line to be active, a signal RD indicates a read command, and a signal WT indicates a write command. 
         [0009]    The conventional row fuse circuit  140  mainly includes a plurality of laser fuses. A unit laser fuse stores ‘high’ or ‘low’ data according to whether the fuse has been cut. Programming of the laser fuse is possible only at a wafer level, that is, it is not possible to program the laser fuse at a package level. Furthermore, it is difficult to design the laser fuse to have a smaller area due to the limitation of a line pitch. 
         [0010]    In order to overcome such disadvantages of the laser fuse, a nonvolatile memory, such as an efuse array circuit, a NAND flash memory, a NOR flash memory, an EPROM (Erasable Programmable Read Only Memory), an EEPROM (Electrically Erasable Programmable Read Only Memory), a FRAM (Ferroelectric RAM), or a MRAM (Magnetoresistive RAM), is mounted in a memory device, and repair information is stored in the nonvolatile memory, as disclosed in U.S. Pat. Nos. 6,904,751, 6,777,757, 6,667,902, 7,173,851, and 7,269,047. 
         [0011]      FIG. 2  is a block diagram illustrating a memory device in which a nonvolatile memory is used to store repair information. 
         [0012]    Referring to  FIG. 2 , the memory device includes a plurality of memory banks BK 0  to BK 3 , registers  210 _ 0  to  210 _ 3  provided to the memory banks BK 0  to BK 3  to store repair information, and a nonvolatile memory  201 . 
         [0013]    The nonvolatile memory  201  is provided instead of the fuse circuit  140 . The nonvolatile memory  201  stores repair information (i.e., repair addresses) corresponding to the memory banks BK 0  to BK 3 . The nonvolatile memory may be one of an efuse array circuit, a NAND flash memory, a NOR flash memory, an EPROM, an EEPROM, a FRAM, and a MRAM. 
         [0014]    The registers  210 _ 0  to  210 _ 3  are configured to be provided to the corresponding memory banks BK 0  to BK 3  and store repair information for the corresponding memory banks, respectively. That is, the register  210 _ 0  is configured to store repair information for the memory bank BK 0 , and the register  210 _ 2  is configured to store repair information for the memory bank BK 2 . The registers  210 _ 0  to  210 _ 3  include latch circuits, and are configured to store the repair information only when power is supplied thereto. The repair information to be stored in the registers  210 _ 0  to  210 _ 3  is received from the nonvolatile memory  201 . 
         [0015]    Since the nonvolatile memory  201  is provided in an array type, a certain time is required to call data stored therein. Thus, it may not be possible to directly perform a repair operation using the data stored in the nonvolatile memory  201 . In this regard, the repair information stored in the nonvolatile memory  201  is transmitted to and stored in the registers  210 _ 0  to  210 _ 3 , and data stored in the registers  210 _ 0  to  210 _ 3  is used for repair operations for the corresponding memory banks BK 0  to BK 3 . The process, in which the repair information stored in the nonvolatile memory  201  is transmitted to the registers  210 _ 0  to  210 _ 3 , is called boot-up, and such a boot-up operation is performed in an initialization operation of the memory device. 
       SUMMARY 
       [0016]    Exemplary embodiments of the present invention are directed to a technology for programming a failed address to a nonvolatile memory through a test in a memory device using the nonvolatile memory to store repair information. 
         [0017]    In accordance with an embodiment of the present invention, a method for testing a memory device includes entering a test mode in which two or more memory banks operate in a same manner, allowing a row corresponding to a row address in the two or more memory banks to be activated, latching a bank address and the row address corresponding to the two or more memory banks, writing same data in a column selected by a column address in the two or more memory banks, reading the data written in the writing of the data from the two or more memory banks, checking whether the data read from the two or more memory banks in the reading of the data are equal to each other, and programming the row address to locations designated by the bank address latched in the latching in a nonvolatile memory when the data read from the two or more memory banks are different from each other. 
         [0018]    In accordance with another embodiment of the present invention, a memory device includes first to N th  bank groups (N is an integer equal to or more than 2), each of which including two or more memory banks configured to simultaneously perform an active operation in response to same row address and to simultaneously perform read and write operations in response to same column address when a test mode is set, a bank selection unit configured to select one bank group for performing active, read, and write operations from the first to N th  bank groups in response to a bank address when the test mode is set, a latch unit configured to latch the bank address and the row address in the active operation in which the test mode has been set, a fail flag generation unit configured to compare data read from memory banks in the selected bank group when the test mode is set, and to generate a fail flag based on the comparison result, and a nonvolatile memory configured to store the row address latched in the latch unit in a location designated by the bank address latched in the latch unit when the fail flag is activated. 
         [0019]    In accordance with yet another embodiment of the present invention, a memory device includes a plurality of memory banks configured to allow a row corresponding to a row address to be activated when bank activation signals corresponding to the plurality of memory banks are activated, and to perform read and write operations for a column corresponding to a column address when bank selection signals corresponding to the plurality of memory banks are activated, a bank selection unit configured to generate the bank selection signals in response to a bank address, and to simultaneously activate two or more bank selection signals when a test mode is set, a bank active control unit configured to generate the bank activation signals in response to an active command and the bank selection signals, a plurality of input/output circuits configured to be provided to the corresponding memory banks, to be activated in response to the corresponding bank selection signal, to transfer write data to the corresponding memory banks in a write operation, and to output read data from the corresponding memory bank in a read operation, a latch unit configured to latch the bank address and the row address when the active command is activated after the test mode is set, a fail flag generation unit configured to compare read data transferred from the input/output circuits corresponding to the activated bank selection signals when the test mode is set, and to generate a fail flag based on the comparison result, and a nonvolatile memory configured to store the row address latched in the latch unit in a location designated by the bank address latched in the latch unit when the fail flag is activated. 
         [0020]    In accordance with still another embodiment of the present invention, a memory device includes first to N th  bank groups (N is an integer equal to or more than 2), each of which including two or more memory banks configured to allow row corresponding to row address to be active when bank activation signals corresponding to the memory banks are activated, and to perform read and write operations for column corresponding to column address when bank selection signals corresponding to the memory banks are activated, a bank selection unit configured to generate the bank selection signals in response to a bank address, and to activate the plurality of bank selection signals when a test mode is set, a bank active control unit configured to generate the bank activation signals in response to an active command and the bank selection signals, a plurality of input/output circuits configured to be provided to the corresponding memory banks, to be activated in response to the corresponding bank selection signals, to transfer write data to the corresponding memory banks in a write operation, and to output read data from the corresponding memory banks in a read operation, a latch unit configured to latch the row address when the active command is activated after the test mode is set, first to N th  fail flag generation units configured to correspond to the first to N th  bank groups in a one-to-one manner, compare read data transferred from the input/output circuits corresponding to the memory banks in the corresponding bank groups when the test mode is set, and to generate first to N th  fail flags based on the comparison result, and a nonvolatile memory configured to store the row address latched in the latch unit in a location designated by an activated fail flag of the first to N th  fail flags. 
         [0021]    According to the present invention, it may be possible to easily detect a failed row of each bank, and the detected failed row is directly programmed to a nonvolatile memory, and thus, it may be possible to shorten a test time for repairing a failed memory cell. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  is a block diagram illustrating a conventional memory device including a row repair scheme. 
           [0023]      FIG. 2  is a block diagram illustrating a memory device in which a nonvolatile memory is used to store repair information. 
           [0024]      FIG. 3  is a block diagram of a memory device in accordance with an embodiment of the present invention. 
           [0025]      FIG. 4  is a flowchart illustrating a method for testing the memory device shown in  FIG. 3 . 
           [0026]      FIG. 5  is a diagram illustrating a process in which a bank address and a row address stored in the nonvolatile memory in match with each other through the process shown in  FIG. 4  are used for a repair operation of a memory device. 
           [0027]      FIG. 6  is a block diagram of a memory device in accordance with another embodiment of the present invention. 
           [0028]      FIG. 7  is a diagram illustrating a process in which a row address is programmed to the nonvolatile memory shown in  FIG. 6  and the row address stored in the nonvolatile memory is used for a repair operation of a memory device. 
           [0029]      FIG. 8  is a block diagram of a memory device in accordance with yet another embodiment of the present invention. 
           [0030]      FIG. 9  is a diagram illustrating a process in which a row address is programmed to the nonvolatile memory shown in  FIG. 8  and the row address stored in the nonvolatile memory is used for a repair operation of a memory device. 
       
    
    
     DETAILED DESCRIPTION 
       [0031]    Exemplary embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. Throughout the disclosure, like reference numerals refer to like parts throughout the various figures and embodiments of the present invention. 
         [0032]      FIG. 3  is a block diagram of a memory device in accordance with an embodiment of the present invention. 
         [0033]    Referring to  FIG. 3 , the memory device includes a plurality of memory banks BK 0  to BK 3 , a bank selection unit  310 , a bank active control unit  320 , a plurality of input/output circuits  330 _ 0  to  330 _ 3 , a latch unit  340 , a fail flag generation unit  350 , a nonvolatile memory  360 , and a plurality of input/output pads DQ&lt;0:7&gt;. 
         [0034]    The plurality of memory banks BK 0  to BK 3  are configured to allow a word line corresponding to row address R_ADD&lt;0:N&gt; to be activated when corresponding bank activation signals RACT 0  to RACT 3  is activated, to allow data to be written in a bit line corresponding to column address C_ADD&lt;0:M&gt; in response to a write command WT when corresponding bank selection signals BS 0  to BS 3  is activated, and to allow data to be read from a bit line corresponding to a column address C_ADD&lt;0:M&gt; in response to a read command RD when the corresponding bank selection signals BS 0  to BS 3  is activated. For example, the memory bank BK 1  allows the word line selected by the row address R_ADD&lt;0:N&gt; to be activated when the bank activation signal RACT 1  is activated, and allows data to be written in the bit line selected by the column address C_ADD&lt;0:M&gt; in response to the write command WT or allows data to be read from the bit line selected by the column address C_ADD&lt;0:M&gt; in response to the read command RD when the corresponding bank selection signal BS 1  is activated. 
         [0035]    The bank selection unit  310  is configured to generate the plurality of bank selection signals BS 0  to BS 3  in response to bank address BA&lt;0:1&gt;. When a test mode signal TDRM is deactivated, that is, during a normal operation, the bank selection unit  310  decodes all bits of the bank address BA&lt;0:1&gt; and activates one of the bank selection signals BS 0  to BS 3 . However, when the test mode signal TDRM is activated, the bank selection unit  310  decodes a partial bit BA&lt;1&gt; of the bank address BA&lt;0:1&gt; and activates two bank selection signals at a time. The test mode signal TDRM is activated during a test mode in which two or more memory banks simultaneously operate in order to find a failed row. Referring to Table 1 below, it is possible to recognize an operation of the bank selection unit  310  when the test mode signal TDRM is activated (TDRM=1) and is deactivated (TDRM=0). 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                   
                   
                 Activated bank 
               
               
                   
                 TDRM 
                 BA&lt;1&gt; 
                 BA&lt;0&gt; 
                 selection signal 
               
               
                   
                   
               
             
             
               
                   
                 0 
                 0 
                 0 
                 BS0 
               
               
                   
                 0 
                 0 
                 1 
                 BS1 
               
               
                   
                 0 
                 1 
                 0 
                 BS2 
               
               
                   
                 0 
                 1 
                 1 
                 BS3 
               
               
                   
                 1 
                 0 
                 don&#39;t care 
                 BS0, BS1 
               
               
                   
                 1 
                 1 
                 don&#39;t care 
                 BS2, BS3 
               
               
                   
                   
               
             
          
         
       
     
         [0036]    The bank active control unit  320  is configured to generate the bank activation signals RACT 0  to RACT 3 , corresponding to each of the memory banks BK 0  to BK 3 , using an active command ACT and the bank selection signals BS 0  to BS 3 . When the active command ACT is activated, the bank active control unit  320  activates a bank activation signal corresponding to an activated signal among the bank selection signals BS 0  to BS 3 . When a precharge command PCG is activated, the bank active control unit  320  deactivates the bank activation signal corresponding to the activated signal among the bank selection signals BS 0  to BS 3 . For example, when the bank selection signal BS 2  and the active command ACT are activated, the bank active control unit  320  activates the bank activation signal RACT 2 . Meanwhile, when the bank selection signal BS 2  and the precharge command PCG are activated, the bank active control unit  320  deactivates the bank activation signal RACT 2 . When the bank activation signals RACT 0  to RACT 3  are activated once, the bank activation signals RACT 0  to RACT 3  maintain the activated state until the bank activation signals RACT 0  to RACT 3  are deactivated by the precharge command PCG. 
         [0037]    The latch unit  340  is configured to latch the bank address BA&lt;1&gt; and the row address R_ADD&lt;0:N&gt; when the active command ACT and the test mode signal TDRM are activated. At the time of the activation of the test mode signal TDRM, since the other one BA&lt;0&gt; of the bank address BA&lt;0:1&gt; is in “don&#39;t care” state, the latch unit  340  latches only the BA&lt;1&gt;. That is, the latch unit  340  latches the bank address BA&lt;1&gt; and the row address R_ADD&lt;0:N&gt; in an active operation. 
         [0038]    The plurality of input/output pads DQ&lt;0:7&gt; are pads through which data is input from an external source, or data is externally output from the memory device. A data bus DATA_BUS is used to transmit data to be input or output through the plurality of input/output pads DQ&lt;0:7&gt;. In the present embodiment, it is assumed that the number of the input/output pads DQ&lt;0:7&gt; is 8. 
         [0039]    The plurality of input/output circuits  330 _ 0  to  330 _ 3  are provided to the memory banks BK 0  to BK 3 , respectively. The plurality of input/output circuits  330 _ 0  to  330 _ 3  are activated when the bank selection signals BS 0  to BS 3  corresponding to the input/output circuits  330 _ 0  to  330 _ 3  are activated. The plurality of input/output circuits  330 _ 0  to  330 _ 3  receive the test mode signal TDRM. In a first case in which the test mode signal TDRM has been deactivated, when the write command WT is activated, the plurality of input/output circuits  330 _ 0  to  330 _ 3  transfer data received from the data bus DATA_BUS to memory banks corresponding to the input/output circuits  330 _ 0  to  330 _ 3 . When the read command RD is activated, the plurality of input/output circuits  330 _ 0  to  330 _ 3  transfer data output from the memory banks corresponding to the input/output circuits  330 _ 0  to  330 _ 3  to the data bus DATA BUS. In a second case in which the test mode signal TDRM has been activated, when the write command WT is activated, the plurality of input/output circuits  330 _ 0  to  330 _ 3  transfer data received from the data bus DATA BUS to the memory banks corresponding to the input/output circuits  330 _ 0  to  330 _ 3 . When the read command RD is activated, the plurality of input/output circuits  330 _ 0  to  330 _ 3  transfer data output from the memory banks corresponding to the input/output circuits  330 _ 0  to  330 _ 3  to the fail flag generation unit  350 . 
         [0040]    The fail flag generation unit  350  is configured to compare read data transferred from the input/output circuits  330 _ 0  to  330 _ 3  corresponding to the activated bank selection signals of the bank selection signals BS 0  to BS 3  when the test mode is set, and to generate a fail flag FAIL based on the comparison result. When read data transferred from the input/output circuits different from one another are equal to each other, the fail flag generation unit  350  deactivates the fail flag FAIL. Otherwise, the fail flag generation unit  350  activates the fail flag FAIL. For example, in a case in which the test mode signal TDRM has been activated and the bank selection signals BS 0  and BS 1  have been activated, when the read command RD is activated, read data are transferred from the input/output circuits  330 _ 0  and  330 _ 1 . When the read data transferred from the input/output circuit  330 _ 0  is equal to the read data transferred from the input/output circuit  330 _ 1 , the fail flag generation unit  350  deactivates the fail flag FAIL. When the read data transferred from the input/output circuit  330 _ 0  is different from the read data transferred from the input/output circuit  330 _ 1 , the fail flag generation unit  350  activates the fail flag FAIL. 
         [0041]    When the fail flag FAIL is activated, the nonvolatile memory  360  matches the bank address and the row address stored in the latch unit  340  with each other, and stores them. That is, when the fail flag FAIL is activated, the bank address and the row address are programmed to the nonvolatile memory. The matched bank address and row address stored in the nonvolatile memory  360  are used for the repair operation of the memory device. The nonvolatile memory  360  may be one of an efuse array circuit, a NAND flash memory, a NOR flash memory, an EPROM, an EEPROM, a FRAM, and a MRAM. 
         [0042]      FIG. 4  is a flowchart illustrating a method for testing the memory device shown in  FIG. 3 . 
         [0043]    Referring to  FIG. 4 , the test mode signal TDRM is activated, so that a test mode is set (S 410 ). The test mode signal TDRM may be activated by applying a setting-related control signal, such as a mode register set (MRS) command, to the memory device. In the test mode in which the test mode signal TDRM has been activated, two or more memory banks simultaneously operate like one. For example, the memory banks BK 0  and BK 1  simultaneously operate like one and the memory banks BK 2  and BK 3  simultaneously operate like one. The memory banks BK 0  and BK 1  may be grouped into a first bank group, and the memory banks BK 2  and BK 3  may be grouped into a second bank group. 
         [0044]    In two or more memory banks, the word lines corresponding to the row address R_ADD&lt;0:N&gt; are activated (S 420 ). When the active command ACT is activated, if the bank address BA&lt;1&gt; is ‘0’, the word lines corresponding to the row address R_ADD&lt;0:N&gt; in the memory banks BK 0  and BK 1  are activated. Meanwhile, if the bank address BA&lt;1&gt; is ‘1’, the word lines corresponding to the row address R_ADD&lt;0:N&gt; in the memory banks BK 2  and BK 3  are activated. For example, when the active command ACT is activated, if the bank address BA&lt;1&gt; is ‘0’ and the row address R_ADD&lt;0:N&gt; indicate 230 th  word line, the 230 th  word line in the memory banks BK 0  and BK 1  are active. Hereinafter, it is assumed that the 230 th  word lines in the memory banks BK 0  and BK 1  have been activated. 
         [0045]    The bank address BA&lt;1&gt; and the row address R_ADD&lt;0:N&gt; corresponding to the active memory banks BK 0  and BK 1  are latched (S 430 ). Since the 230 th  word lines in the memory banks BK 0  and BK 1  have been activated, the bank address BA&lt;1&gt; is latched to ‘0’ and the row address RADD&lt;0:N&gt; are latched to values corresponding to the 230 th  word line. Steps S 420  and S 430  are performed in response to the activation of the active command ACT. Steps S 420  and S 430  may be simultaneously performed, or step S 430  may be performed before step S 420 . 
         [0046]    Then, the same data is written in the activated memory banks BK 0  and BK 1  (S 440 ). In a state in which the bank address BA&lt;1&gt; has been applied to ‘0’, when the write command WT is activated, data is written in the bit lines corresponding to the column address C_ADD&lt;0:M&gt; in the memory banks BK 0  and BK 1 . As a consequence, the same data is written in the same location in the memory banks BK 0  and BK 1 . 
         [0047]    Then, the data written in the memory banks BK 0  and BK 1  in step S 440  are read therefrom (S 450 ). Similar to step S 440 , step S 450  may be performed by activating the read command RD in a state in which the bank address BA&lt;1&gt; and the column address C_ADD&lt;0:M&gt; have been applied. As a consequence, in step S 450 , the data written in the memory banks BK 0  and BK 1  in step S 440  are read as is. 
         [0048]    Then, it is checked whether the data read from the memory banks BK 0  and BK 1  in step S 450  are equal to each other (S 460 ). When the data read from the memory bank BK 0  is equal to the data read from the memory bank BK 1 , the fail flag generation unit  350  deactivates the fail flag FAIL. In this case, it may be possible to assume that there is no error in the 230 th  word line of the memory bank BK 0  and the 230 th  word line of the memory bank BK 1 . When the data read from the memory bank BK 0  is different from the data read from the memory bank BK 1 , the fail flag generation unit  350  activates the fail flag FAIL. In this case, it may be possible to assume that there is an error in the 230 th  word line of the memory bank BK 0  and the 230 th  word line of the memory bank BK 1 . 
         [0049]    When the fail flag FAIL is activated in step S 460 , the bank address BA&lt;1&gt; and the row address R_ADD&lt;0:N&gt; latched in step S 430  are matched with each other, and are programmed to the nonvolatile memory  360  (S 470 ). When the fail flag FAIL is deactivated in step S 460 , the test operation is completed (if all columns are tested), or steps S 440 , S 450 , S 460 , and S 470  may be performed repeatedly while changing the column address C_ADD&lt;0:M&gt;, until the test operation to the 230 th  word line is completed. 
         [0050]    Alternatively, steps S 420 , S 430 , S 440 , S 450 , S 460 , and S 470  of  FIG. 4  may be performed repeatedly while changing the row address R_ADD&lt;0:N&gt; and/or the bank address BA&lt;1&gt;. 
         [0051]    Through the test method illustrated in  FIG. 4 , a failed row in the memory device may be quickly found, and when the failed row is found, the failed row may be directly programmed to the nonvolatile memory  360 , so that the memory device is repaired. 
         [0052]      FIG. 5  is a diagram for explaining a process in which the bank address and the row address stored in the nonvolatile memory  360  in match with each other through the process shown in  FIG. 4  are used for the repair operation of the memory device. 
         [0053]    Referring to  FIG. 5 , the bank address BA&lt;1&gt; and the row address R_ADD&lt;0:N&gt; are matched with each other, and are stored in the nonvolatile memory  360 . Among them, row address  501  and  503  stored in match with the bank address BA&lt;1&gt; having a value of ‘0’ are transferred to and stored in registers  510 _ 0  and  510 _ 1 . Row address  502 ,  504 , and  505  stored in match with the bank address BA&lt;1&gt; having a value of ‘1’ are transferred to and stored in registers  510 _ 2  and  510 _ 3 . That is, the bank address BA&lt;1&gt; stored in the nonvolatile memory  360  designates the registers  510 _ 0  to  510 _ 3  to which the matched and stored row address  501  to  505  are to be transferred. 
         [0054]    The row address  501  and  503  are received and stored in the registers  510 _ 0  and  510 _ 1 , and are used for repairing the row of the memory banks BK 0  and BK 1 . Thus, in the memory banks BK 0  and BK 1 , a 123 th  word line and a 201 th  word line are replaced with redundant word line, respectively. Similarly, since the registers  510 _ 2  and  510 _ 3  receive and store the row address  502 ,  504 , and  505 , a 67 th  word line, a 100 th  word line, and a 213 th  word line are replaced with redundant word line in the memory banks BK 2  and BK 3 . 
         [0055]      FIG. 6  is a block diagram of a memory device in accordance with another embodiment of the present invention. 
         [0056]    Referring to  FIG. 6 , the memory device includes a plurality of memory banks BK 0  to BK 3 , a bank selection unit  310 , a bank active control unit  320 , a plurality of input/output circuits  330 _ 0  to  330 _ 3 , a latch unit  340 , a fail flag generation unit  350 , a nonvolatile memory  660 , and a plurality of input/output pads DQ&lt;0:7&gt;. In the present embodiment, a row address storage scheme of the nonvolatile memory  660  is different from the embodiment of  FIG. 3 . In  FIG. 6 , the same reference numerals are used to designate the same elements of the embodiment of  FIG. 3 . 
         [0057]    In the embodiment of  FIG. 3 , when the fail flag FAIL is activated, the nonvolatile memory  360  matches the bank address and the row address stored in the latch unit  340  with each other and programs the addresses. However, in the embodiment of  FIG. 6 , when the fail flag FAIL is activated, the nonvolatile memory  660  programs only the row address latched in the latch unit  340 . A row address storage location in the nonvolatile memory  660  is determined by the bank address latched in the latch unit  340 . 
         [0058]      FIG. 7  is a diagram for explaining a process in which the row address is programmed to the nonvolatile memory  660  shown in  FIG. 6  and the row address stored in the nonvolatile memory  660  is used for a repair operation of the memory device. 
         [0059]    Referring to  FIG. 7 , the nonvolatile memory  660  includes storages  710  and  720  including a plurality of memory sets  711  to  715  and  721  to  725 . The memory sets  711  to  715  and  721  to  725  are configured to store data corresponding to a bit number (N+1 bits) of the row address R_ADD&lt;0:N&gt;, respectively. When the fail flag FAIL is activated, if the bank address BA&lt;1&gt; latched in the latch unit  340  is ‘0’ (that is, corresponds to the bank group including the memory banks BK 0  and BK 1 ), the row address R_ADD&lt;0:N&gt; latched in the latch unit  340  are stored in one of the memory sets  711  to  715  in the storage  710  of the nonvolatile memory  660 . Meanwhile, when the fail flag FAIL is activated, if the bank address BA&lt;1&gt; latched in the latch unit  340  is ‘1’ (that is, corresponds to the bank group including the memory banks BK 2  and BK 3 ), the row address R_ADD&lt;0:N&gt; latched in the latch unit  340  are stored in one of the memory sets  721  to  725  in the storage  720  of the nonvolatile memory  660 . 
         [0060]    The memory sets  711  to  715  in the storage  710  may have priorities. When the fail flag FAIL is first activated in the state in which the bank address BA&lt;1&gt; has a value of ‘0’, the row address R_ADD&lt;0:N&gt; are stored in the memory set  711 . Then, when the fail flag FAIL is activated again in the state in which the bank address BA&lt;1&gt; has a value of ‘0’, the row address R_ADD&lt;0:N&gt; are stored in the memory set  712 . Similarly, the memory sets  721  to  725  in the storage  720  may have priorities. 
         [0061]    The storages  710  and  720  correspond to the bank groups in a one-to-one manner. The storage  710  corresponds to a first bank group including the memory banks BK 0  and BK 1 , and the storage  720  corresponds to a second bank group including the memory banks BK 2  and BK 3 . The row address stored in the memory sets  711  to  715  and  721  to  725  in the storages  710  and  720  are used for repair operations of the corresponding bank groups. That is, the row address stored in the memory sets  711  to  715  are transmitted to the registers  510 _ 0  to  510 _ 1  and are used for the repair operation, and the row address stored in the memory sets  721  to  725  are transmitted to the registers  510 _ 2  to  510 _ 3  and are used for the repair operation. 
         [0062]    In accordance with the embodiment described in  FIG. 6  and  FIG. 7 , the bank address BA&lt;1&gt; is not stored in (programmed to) the nonvolatile memory  660 , but the internal areas  710  and  720  of the nonvolatile memory  660  are divided to correspond to the bank groups and the row address R_ADD&lt;0:N&gt; are stored in corresponding areas, so that the repair operation is performed according to the bank group. 
         [0063]      FIG. 8  is a block diagram of a memory device in accordance with yet another embodiment of the present invention. 
         [0064]    Referring to  FIG. 8 , the memory includes a plurality of memory banks BK 0  to BK 3 , a bank selection unit  810 , a bank active control unit  820 , a plurality of input/output circuits  330 _ 0  to  330 _ 3 , a latch unit  840 , fail flag generation units  850 _ 0  and  850 _ 1 , a nonvolatile memory  860 , and a plurality of input/output pads DQ&lt;0:7&gt;. In  FIG. 8 , a description will be provided for an embodiment in which all memory banks BK 0  to BK 3  simultaneously operate in the test mode. In the embodiment of  FIG. 8 , the same reference numerals are used to designate the same elements of the embodiment of  FIG. 3 . 
         [0065]    When the test mode signal TDRM is deactivated (that is, in the normal operation), the bank selection unit  810  decodes the bank address BA&lt;0:1&gt; and activates one of the bank selection signals BS 0  to BS 3 . However, when the test mode signal TDRM is activated, the bank selection unit  810  activates all the bank selection signals BS 0  to BS 3 . Referring to Table 2 below, it may be possible to recognize an operation of the bank selection unit  810  when the test mode signal TDRM is activated (TDRM=1) and is deactivated (TDRM=0). 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                   
                   
                   
                 Activated bank 
               
               
                   
                 TDRM 
                 BA&lt;1&gt; 
                 BA&lt;0&gt; 
                 selection signal 
               
               
                   
                   
               
             
             
               
                   
                 0 
                 0 
                 0 
                 BS0 
               
               
                   
                 0 
                 0 
                 1 
                 BS1 
               
               
                   
                 0 
                 1 
                 0 
                 BS2 
               
               
                   
                 0 
                 1 
                 1 
                 BS3 
               
               
                   
                 1 
                 don&#39;t care 
                 don&#39;t care 
                 BS0, BS1, BS2, BS3 
               
               
                   
                   
               
             
          
         
       
     
         [0066]    In the test mode, since the bank selection unit  810  activates all the bank selection signals BS 0  to BS 3 , all memory banks BK 0  to BK 3  operate like one in the same manner. 
         [0067]    The latch unit  840  is configured to latch the row address R_ADD&lt;0:N&gt; when the active command ACT is activated at the time of activation of the test mode signal TDRM. In the embodiment of  FIG. 3 , the latch unit  340  latches both the bank address BA&lt;0:1&gt; and the row address R_ADD&lt;0:N&gt;. However, the latch unit  840  of the present embodiment latches only the row address R_ADD&lt;0:N&gt;. 
         [0068]    In  FIG. 8 , the fail flag generation units  850 _ 0  and  850 _ 1  are provided to the bank groups, respectively. The fail flag generation unit  850 _ 0  is provided to the bank group including the memory banks BK 0  and BK 1 , and the fail flag generation unit  850 _ 1  is provided to the bank group including the memory banks BK 2  and BK 3 . At the time of activation of the test mode signal TDRM, the fail flag generation unit  850 _ 0  compares read data of the memory bank BK 0  transferred from the input/output circuit  330 _ 0  with read data of the memory bank BK 1  transferred from the input/output circuit  330 _ 1 , deactivates a fail flag FAIL 0  when the read data of the memory bank BK 0  is equal to the read data of the memory bank BK 1 , and activates the fail flag FAIL 0  when the read data of the memory bank BK 0  is different from the read data of the memory bank BK 1 . Similarly, at the time of activation of the test mode signal TDRM, the fail flag generation unit  850 _ 1  compares read data of the memory bank BK 2  transferred from the input/output circuit  330 _ 2  with read data of the memory bank BK 3  transferred from the input/output circuit  330 _ 3 , deactivates a fail flag FAIL 1  when the read data of the memory bank BK 2  is equal to the read data of the memory bank BK 3 , and activates the fail flag FAIL 1  when the read data of the memory bank BK 2  is different from the read data of the memory bank BK 3 . 
         [0069]    The nonvolatile memory  860  is configured to store the row address R_ADD&lt;0:N&gt; latched in the latch unit  840  when the fail flags FAIL 0  and FAIL 1  are activated. Locations for storing the row address R_ADD&lt;0:N&gt; in the nonvolatile memory  860  are determined by the fail flags FAIL 0  and FAIL 1 . 
         [0070]    In accordance with the embodiment shown in  FIG. 8 , it may be possible to detect and store failed row address while simultaneously testing all the memory banks BK 0  to BK 3 , which may significantly shorten a test time. 
         [0071]      FIG. 9  is a diagram for explaining a process in which the row address is programmed to the nonvolatile memory  860  of  FIG. 8  and the row address stored in the nonvolatile memory  860  is used for a repair operation of the memory device. 
         [0072]    Referring to  FIG. 9 , the nonvolatile memory  860  includes storages  910  and  920  including a plurality of memory sets  911  to  915  and  921  to  925 . The memory sets  911  to  915  and  921  to  925  are configured to store data corresponding to a bit number (N+1 bits) of the row address R_ADD&lt;0:N&gt;, respectively. When the fail flag FAIL 0  is activated, the row address R_ADD&lt;0:N&gt; latched in the latch unit  840  are stored in one of the memory sets  911  to  915  in the storage  910  of the nonvolatile memory  860 . Meanwhile, when the fail flag FAIL 1  is activated, the row address R_ADD&lt;0:N&gt; latched in the latch unit  840  are stored in one of the memory sets  921  to  925  in the storage  920  of the nonvolatile memory  860 . When the fail flag FAIL 0  and the fail flag FAIL 1  are simultaneously activated, the same row address R_ADD&lt;0:N&gt; are stored in one of the memory sets  911  to  915  in the storage  910  and one of the memory sets  921  to  925  in the storage  920 . 
         [0073]    The memory sets  911  to  915  and  921  to  925  in the storages  910  and  920  may have priorities. When the fail flag FAIL 0  is primarily activated, the row address R_ADD&lt;0:N&gt; are stored in the memory set  911 . Then, when the fail flag FAIL 0  is secondarily activated, the row address R_ADD&lt;0:N&gt; are stored in the memory set  912 . Similarly, when the fail flag FAIL 1  is primarily activated, the row address R_ADD&lt;0:N&gt; are stored in the memory set  921 . Then, when the fail flag FAIL 1  is secondarily activated, the row address R_ADD&lt;0:N&gt; are stored in the memory set  922 . 
         [0074]    The storages  910  and  920  correspond to the bank groups in a one-to-one manner. The storage  910  corresponds to the bank group including the memory banks BK 0  and BK 1 , and the storage  920  corresponds to the bank group including the memory banks BK 2  and BK 3 . The row address stored in the memory sets  911  to  915  and  921  to  925  in the storages  910  and  920  are used for repair operations of corresponding to bank groups. That is, the row address stored in the memory sets  911  to  915  are transmitted to the registers  510 _ 0  to  510 _ 1  and are used for the repair operation, and the row address stored in the memory sets  921  to  925  are transmitted to the registers  510 _ 2  to  510 _ 3  and are used for the repair operation. 
         [0075]    In accordance with the embodiment described in  FIG. 8  and  FIG. 9 , the separate fail flags FAIL 0  and FAIL 1  are generated for the bank groups, respectively. Furthermore, the bank address BA&lt;1&gt; is not stored in (programmed to) the nonvolatile memory, but the internal spaces of storages  910  and  920  of the nonvolatile memory  860  are divided to correspond to the bank groups and the row address R_ADD&lt;0:N&gt; that are stored according to corresponding fail flags FAIL 0  and FAIL 1 , so that the repair operation is performed according to the bank group. 
         [0076]    While the present invention has been described with respect to the specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.