Patent Publication Number: US-10311923-B2

Title: Input circuit of three-dimensional semiconductor apparatus capable of enabling testing and direct access

Description:
CROSS-REFERENCES TO RELATED APPLICATION 
     The present application is a divisional application of U.S. application Ser. No. 14/634,167, filed on Feb. 27, 2015, and claims priority under 35 U.S.C. § 119 (a) to Korean application number 10-2014-0174416, filed on Dec. 5, 2014, in the Korean Intellectual Property Office, which is incorporated herein by reference in its entirety as set forth in full. 
    
    
     BACKGROUND 
     1. Technical Field 
     Various embodiments generally relate to a semiconductor apparatus, and more particularly, to an input circuit of a semiconductor apparatus and a semiconductor system using the same. 
     2. Related Art 
     A semiconductor memory may have a three-dimensional structure. The three-dimensional structure may include a plurality of memory dies that are stacked. Stacking the memory dies may be used as one method for improving an integration degree of a semiconductor memory. 
     Recently, a system on chip (SOC) type of semiconductor apparatus is being used. The SOC type of semiconductor apparatus uses a semiconductor memory module and a memory controller such as, for example, a CPU or a GPU. The semiconductor memory module and a memory controller of a SOC type semiconductor apparatus are fabricated into one package. 
     A SOC type of semiconductor apparatus may include a plurality of bumps for inputting and outputting data. 
     Because the pluralities of bumps are not exposed to an exterior of a package, a separate configuration may be required in order to directly access a semiconductor memory module. 
     SUMMARY 
     In an embodiment, an input circuit of a semiconductor apparatus may include a first input buffer configured to receive a signal through a test input terminal and to output a first input signal. The input circuit of a semiconductor apparatus may include a second input buffer configured to receive a signal through a normal input terminal and to output a second input signal. The input circuit of a semiconductor apparatus may include a switching unit configured to transfer the signal inputted through the test input terminal to the second input buffer according to a test mode signal. The input circuit of a semiconductor apparatus may include a comparison unit configured to compare the first input signal with the second input signal and to generate a comparison signal, and a storage unit configured to store the comparison signal. 
     In an embodiment, a semiconductor system may include a package substrate configured with a plurality of test input terminals are positioned below the package substrate, and an interposer coupled to an upper portion of the package substrate. The semiconductor system may include a memory module coupled to an upper portion of the interposer and including a plurality of normal input terminals. The semiconductor system may include a memory controller located on the interposer and coupled to the memory module. The memory module may be configured to test whether an input circuit coupled to the plurality of normal input terminals normally operates according to a signal inputted through the test input terminal. 
     In an embodiment, an input circuit of a semiconductor apparatus may include a first input buffer configured to receive a signal through a test input terminal and to output a first input signal. The input circuit of the semiconductor apparatus may include a second input buffer configured to receive a signal through a normal input terminal and to output a second input signal. The input circuit of the semiconductor apparatus may include a direct access mode circuit configured to perform an operation related to a direct access mode according to the first input signal. The input circuit of the semiconductor apparatus may include a normal mode circuit configured to perform an operation including data write or read related to a normal mode according to the second input signal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating an example of a representation of a configuration of a semiconductor system  100  according to an embodiment. 
         FIG. 2  is a diagram illustrating an example of a representation of a configuration of an input circuit  101  according to an embodiment. 
         FIG. 3  is a diagram illustrating an example of a representation of a configuration of an input circuit  102  according to an embodiment. 
         FIG. 4  is a timing diagram illustrating an example of a representation of an operation of an input circuit  102  of  FIG. 3 . 
         FIG. 5  illustrates a block diagram of an example of a representation of a system employing the input circuit of a semiconductor apparatus and/or semiconductor system in accordance with the embodiments discussed above with relation to  FIGS. 1-4 . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, an input circuit of a semiconductor apparatus and a semiconductor system using the same according to various embodiments will be described with reference to the accompanying drawings through examples of various embodiments. 
     An input circuit of a semiconductor apparatus configured for enabling direct access and an input test and a semiconductor system using the same may be described herein. 
     Referring to  FIG. 1 , a semiconductor system  100  according to an embodiment may have a system on chip (SOC) structure. 
     The semiconductor system  100  according to an embodiment may include a memory module, a memory controller (a CPU or a GPU), an interposer, a package substrate, and a plurality of test input terminals. 
     For the plurality of test input terminals, direct access balls (DABs) may be used for example but the embodiments are not limited in this manner. 
     The interposer may be coupled to an upper portion of the package substrate. 
     The memory module and the memory controller (a CPU or a GPU) may be coupled to an upper portion of the interposer. 
     Physical areas PHY of the memory module and the memory controller (a CPU or a GPU) may be coupled to each other through the interposer. 
     The memory module may have a configuration including a plurality of dies that are stacked. 
     The plurality of dies may include the lowermost base die and a plurality of core dies stacked on the base die. 
     The base die and the plurality of core dies may be electrically connected or coupled to each other through a through electrode (for example, a TSV (Through Silicon Via)), and are configured such that data, commands, and addresses may be transmitted. 
       FIG. 1  illustrates only one memory module, and in an actual circuit configuration, a plurality of memory modules may be coupled to the memory controller (a CPU or a GPU) through the interposer. 
     A plurality of direct access balls (DABs) may be formed outside the package substrate. 
     The plurality of direct access balls (DABs) may be electrically connected or coupled to the memory module via the package substrate and the interposer. 
     The direct access balls (DABs) may be configured such that the memory module may be directly accessed from the exterior of the semiconductor system  100  for a test and/or other operations. 
     Referring to  FIG. 2 , an input circuit  101  according to an embodiment may include a first input buffer  200  and a second input buffer  300 . 
     The input circuit  101  according to an embodiment may further include a direct access mode circuit (hereinafter, referred to as a DA mode circuit)  210  and a normal mode circuit  310 . 
     The first input buffer  200  may be configured to receive a signal through a direct access ball (DAB) and to output a first input signal DAIN. 
     The DA mode circuit  210  may be configured to perform an operation related to a DA mode according to the first input signal DAIN. 
     The second input buffer  300  may be configured to receive a signal through a normal input terminal  500  and to output a second input signal DIN. 
     The normal input terminal  500  may include a micro bump. 
     The normal input terminal  500  may not be exposed to the exterior of the package and may be formed within the package. 
     The normal input terminal  500  may be configured to receive data DOUT through an output buffer  400 . The data DOUT may be outputted from the memory module. The normal input terminal  500  may be configured to output the data DOUT to the exterior of the memory module. 
     The normal mode circuit  310  may be configured to perform an operation (for example, data write and read operations and the like) related to a normal mode according to the second input signal DIN. 
     As described above, the direct access ball (DAB) may be electrically connected or coupled to the memory module via the package substrate and the interposer. 
     The input circuit  101  according to an embodiment may be configured in the memory module, for example, the base die. 
     In the input circuit  101  according to an embodiment, data inputted through the normal input terminal  500  from the exterior of the semiconductor system  100  or the memory controller (a CPU or a GPU) together with a write command, may be transferred to the normal mode circuit  310  through the second input buffer  300 , so that a data read operation may be performed by the normal mode circuit  310 . 
     Data, inputted from a test equipment through the direct access ball (DAB) in order to directly test the memory module, may be transferred to the DA mode circuit  210  through the first input buffer  200 , so that a memory module test operation may be performed by the DA mode circuit  210 . 
     In the aforementioned input circuit  101  according to an embodiment, one normal input terminal  500 , one direct access ball (DAB), one first input buffer  200 , and one second input buffer  300  may be configured for the purposes of convenience. However, the first input buffer  200  and the second input buffer  300  may be configured in proportion to the number of the normal input terminals  500  and the number of the direct access balls (DABs). 
     Referring to  FIG. 3 , an input circuit  102  according to an embodiment may include the first input buffer  200 , the second input buffer  300 , and a switching unit  800 . The input circuit  102  may include a comparison unit  600 , and a storage unit  700 . 
     The input circuit  102  according to an embodiment may further include the DA mode circuit  210  and the normal mode circuit  310 . 
     The first input buffer  200  may be configured to receive a signal through the test input terminal. The test input terminal may include for example, the direct access ball (DAB). The first input buffer  200  may be configured to output the first input signal DAIN. 
     The DA mode circuit  210  may be configured to perform an operation related to the DA mode according to the first input signal DAIN. 
     The second input buffer  300  may be configured to receive a signal through the normal input terminal  500  and to output the second input signal DIN. 
     The normal input terminal  500  may include a micro bump. 
     The normal input terminal  500  may not be exposed to the exterior of the package and be formed in the package. 
     The normal input terminal  500  may be configured to receive data DOUT through an output buffer  400 . The data DOUT may be outputted from the memory module. The normal input terminal  500  may be configured to output the data DOUT to the exterior of the memory module. 
     The normal mode circuit  310  may be configured to perform an operation (for example, data write and read operations and the like) related to the normal mode according to the second input signal DIN. 
     The switching unit  800  may be configured to transfer the signal inputted through the direct access ball (DAB) to the second input buffer  300  according to test mode signals TM/TMB. 
     The test mode signals TM and TMB may indicate differential signals and may have phases opposite to each other. 
     When the test mode signals TM/TMB are activated, that is for example, when the TM is logic high and the TMB is logic low, the switching unit  800  may transfer the signal inputted through the direct access ball (DAB) to the second input buffer  300 . 
     The comparison unit  600  may be configured to compare the first input signal DAIN outputted from the first input buffer  200  with the second input signal DIN outputted from the second input buffer  300  according to a clock signal CK, and to generate a comparison signal CMP. 
     The comparison unit  600  may be configured to compare the first input signal DAIN outputted from the first input buffer  200  with the second input signal DIN outputted from the second input buffer  300  according to a clock signal CK, and to generate the comparison signal CMP. 
     The comparison unit  600  may include a XNOR logic gate or equivalent circuit and may perform a XNOR logic. 
     The comparison unit  600  may output the comparison signal CMP as logic high when the logic values of the first input signal DAIN and the second input signal DIN are equal or substantially equal to each other, and output the comparison signal CMP as logic low when the logic values of the first input signal DAIN and the second input signal DIN are different from each other. 
     The storage unit  700  may be configured to store the comparison signal CMP. 
     The storage unit  700  may include a register accessible from the exterior of the semiconductor system  100 . 
     As the storage unit  700 , a register for storing a test result of a boundary scan test circuit may be used. 
     As described above, the direct access ball (DAB) may be electrically connected to the memory module via the package substrate and the interposer. 
     The input circuit  102  according to an embodiment may be configured in the memory module, for example, the base die. 
     In the aforementioned input circuit  102  according to an embodiment, one normal input terminal  500 , one direct access ball (DAB), one first input buffer  200 , and one second input buffer  300  may be configured for the purposes of convenience. However, the first input buffer  200 , the second input buffer  300 , and the switching unit  800  may be configured in proportion to the number of the normal input terminals  500  and the number of the direct access balls (DABs). 
     The comparison unit  600  may include XNOR logics proportional to the number of the normal input terminals  500  and the number of the direct access balls (DABs), and the storage unit  700  may also include a plurality of registers. 
     With reference to  FIG. 4 , the operation of the input circuit  102  according to an embodiment will be described. 
     As described above, the normal input terminal  500  may have a micro bump structure, and may not be directly accessed through test equipment located outside the semiconductor system  100 . 
     In this regard, in an embodiment, the operation of the input circuit  102  may be tested using the direct access ball (DAB), and an operation thereof will be described below. 
     The semiconductor system  100  enters a test mode and tests data, for example, logic high data is inputted through the direct access ball (DAB). 
     As the semiconductor system  100  enters the test mode, the test mode signal TM has, for example, a logic high value. 
     At this time, the TMB has, for example, a logic low value. 
     Since the test mode signal TM is logic high, the data inputted through the direct access ball (DAB) is simultaneously inputted to the first input buffer  200  and the second input buffer  300 . 
     When the first input buffer  200  and the second input buffer  300  are normally operating, they simultaneously output the first input signal DAIN of logic high and the second input signal DIN of logic high. 
     Since the logic values of the first input signal DAIN and the second input signal DIN are substantially equal to each other, the comparison unit  600  outputs the comparison signal CMP of logic high. 
     The comparison signal CMP of logic high may be stored in the storage unit  700 . 
     It is possible to test whether the second input buffer  300  is normally operating by reading a value stored in the storage unit  700 . 
     When a logic high value has been stored in the storage unit  700 , the second input buffer  300  may be determined to normally operate. 
     However, when the second input buffer  300  is not normally operating, since the logic values of the first input signal DAIN and the second input signal DIN are different from each other, the comparison unit  600  outputs the comparison signal CMP of logic low. 
     Therefore, since a logic low value is stored in the storage unit  700 , the second input buffer  300  may be determined to not be normally operating. 
     When the test mode is ended and the semiconductor system  100  enters the normal mode, the test mode signal TM has a logic low value. 
     At this time, the TMB has a logic high value. 
     Since the test mode signal TM is logic low, the data inputted through the direct access ball (DAB) is inputted only to the first input buffer  200 . 
     The first input buffer  200  outputs the first input signal DAIN of logic high. 
     Since the test mode signal TM is logic low, data inputted through the normal input terminal  500  is inputted only to the second input buffer  300 . 
     The second input buffer  300  outputs the second input signal DIN of logic high. 
     A value stored in the storage unit  700  may be substantially maintained to a recent test value. 
     The input circuit of a semiconductor apparatus and/or semiconductor system discussed above (see  FIGS. 1-4 ) are particular useful in the design of memory devices, processors, and computer systems. For example, referring to  FIG. 5 , a block diagram of a system employing the input circuit of a semiconductor apparatus and/or semiconductor system in accordance with the embodiments are illustrated and generally designated by a reference numeral  1000 . The system  1000  may include one or more processors or central processing units (“CPUs”)  1100 . The CPU  1100  may be used individually or in combination with other CPUs. While the CPU  1100  will be referred to primarily in the singular, it will be understood by those skilled in the art that a system with any number of physical or logical CPUs may be implemented. 
     A chipset  1150  may be operably coupled to the CPU  1100 . The chipset  1150  is a communication pathway for signals between the CPU  1100  and other components of the system  1000 , which may include a memory controller  1200 , an input/output (“I/O”) bus  1250 , and a disk drive controller  1300 . Depending on the configuration of the system, any one of a number of different signals may be transmitted through the chipset  1150 , and those skilled in the art will appreciate that the routing of the signals throughout the system  1000  can be readily adjusted without changing the underlying nature of the system. 
     As stated above, the memory controller  1200  may be operably coupled to the chipset  1150 . The memory controller  1200  may include at least one input circuit of a semiconductor apparatus and/or semiconductor system as discussed above with reference to  FIGS. 1-4 . Thus, the memory controller  1200  can receive a request provided from the CPU  1100 , through the chipset  1150 . In alternate embodiments, the memory controller  1200  may be integrated into the chipset  1150 . The memory controller  1200  may be operably coupled to one or more memory devices  1350 . In an embodiment, the memory devices  1350  may include the at least one input circuit of a semiconductor apparatus and/or semiconductor system as discussed above with relation to  FIGS. 1-4 , the memory devices  1350  may include a plurality of word lines and a plurality of bit lines for defining a plurality of memory cells. The memory devices  1350  may be any one of a number of industry standard memory types, including but not limited to, single inline memory modules (“SIMMs”) and dual inline memory modules (“DIMMs”). Further, the memory devices  1350  may facilitate the safe removal of the external data storage devices by storing both instructions and data. 
     The chipset  1150  may also be coupled to the I/O bus  1250 . The I/O bus  1250  may serve as a communication pathway for signals from the chipset  1150  to I/O devices  1410 ,  1420  and  1430 . The I/O devices  1410 ,  1420  and  1430  may include a mouse  1410 , a video display  1420 , or a keyboard  1430 . The I/O bus  1250  may employ any one of a number of communications protocols to communicate with the I/O devices  1410 ,  1420 , and  1430 . Further, the I/O bus  1250  may be integrated into the chipset  1150 . 
     The disk drive controller  1450  (i.e., internal disk drive) may also be operably coupled to the chipset  1150 . The disk drive controller  1450  may serve as the communication pathway between the chipset  1150  and one or more internal disk drives  1450 . The internal disk drive  1450  may facilitate disconnection of the external data storage devices by storing both instructions and data. The disk drive controller  1300  and the internal disk drives  1450  may communicate with each other or with the chipset  1150  using virtually any type of communication protocol, including all of those mentioned above with regard to the I/O bus  1250 . 
     It is important to note that the system  1000  described above in relation to  FIG. 5  is merely one example of a system employing the input circuit of a semiconductor apparatus and/or semiconductor system as discussed above with relation to  FIGS. 1-4 . In alternate embodiments, such as cellular phones or digital cameras, the components may differ from the embodiments illustrated in  FIG. 5 . 
     While various embodiments have been described above, it will be understood to those skilled in the art that the embodiments described are by way of example only. Accordingly, the input circuit of a semiconductor apparatus and the semiconductor system using the same described herein should not be limited based on the described embodiments. Rather, the input circuit of a semiconductor apparatus and the semiconductor system using the same described herein should only be limited in light of the claims that follow when taken in conjunction with the above description and accompanying drawings.