阅读说明：本技术 采用有限数量的测试引脚测试存储器件的方法以及利用该方法的存储器件 (Method for testing memory device using limited number of test pins and memory device using the same ) 是由 徐晓东 赵祥明 刘顺临 陈轶 于 2019-10-17 设计创作，主要内容包括：一种方法用于测试包括封装衬底、控制器裸片和存储器裸片的存储器件。封装衬底包括隔离引脚、测试模式选择引脚、测试时钟引脚和测试数据引脚。所述方法包括：将隔离引脚设置为使存储器裸片与控制器裸片隔离的隔离状态；以及在隔离引脚被设置为隔离状态时,将存储器裸片设置为经由测试模式选择引脚、测试时钟引脚和测试数据引脚接收控制。(A method is for testing a memory device that includes a package substrate, a controller die, and a memory die. The package substrate includes an isolation pin, a test mode selection pin, a test clock pin, and a test data pin. The method comprises the following steps: setting an isolation pin to an isolation state that isolates a memory die from a controller die; and setting the memory die to receive control via the test mode select pin, the test clock pin, and the test data pin when the isolation pin is set to the isolated state.)

1. A memory device, comprising:

a package substrate comprising:

isolating the pins;

a test mode selection pin configured to switch an operating mode of the memory die;

a test clock pin configured to receive a test clock; and

a test data pin configured to perform a data transfer;

a controller die disposed on the package substrate and coupled to the isolation pin; and

the memory die disposed on the package substrate and coupled to the test mode select pin, the test clock pin, and the test data pin;

wherein the memory die is configured to receive control via the test mode select pin, the test clock pin, and the test data pin when the isolation pin is configured in an isolation state that isolates the memory die from the controller die.

2. The memory device of claim 1,

the controller die includes a write enable pin and a data pin;

the memory die includes a test register coupled to the write enable pin and the data pin; and is

The controller die is configured to set the test register to a test enabled state via the write enable pin and the data pin; and is

After the test register is set to the test enable state, the isolation pin is set to the isolation state that isolates the memory die from the controller die.

3. The memory device of claim 1, wherein the package substrate further comprises a chip enable pin coupled to the memory die and configured to transmit a chip enable signal to the memory die for enabling the memory die.

4. The memory device of claim 1, wherein the data transfer is associated with a read access to the memory die.

5. The memory device of claim 1, wherein the data transfer is associated with a write access to the memory die.

6. A memory device, comprising:

a package substrate comprising:

isolating the pins;

a test enable pin;

a test mode selection pin configured to switch an operating mode of the memory die;

a test clock pin configured to receive a test clock; and

a test data pin configured to perform a data transfer;

a controller die disposed on the package substrate and coupled to the isolation pin; and

a memory die disposed on the package substrate and coupled to the test enable pin, the test mode select pin, the test clock pin, and the test data pin;

wherein when the isolation pin is set to an isolation state that isolates the memory die from the controller die and the test enable pin is set to a test enabled state, the memory die is set to receive control via the test mode select pin, the test clock pin, and the test data pin.

7. The memory device of claim 6, wherein the package substrate further comprises a chip enable pin coupled to the memory die and configured to transmit a chip enable signal to the memory die for enabling the memory die.

8. The memory device of claim 6, wherein the data transfer is associated with a read access to the memory die.

9. The memory device of claim 6, wherein the data transfer is associated with a write access to the memory die.

10. A method of testing a memory device, the memory device including a package substrate, a controller die, and a memory die, the package substrate including an isolation pin, a test mode selection pin, a test clock pin, and a test data pin, the method comprising:

setting the isolation pin to an isolation state that isolates the memory die from the controller die; and

setting the memory die to receive control via the test mode select pin, the test clock pin, and the test data pin while the isolation pin is set to the isolated state.

11. The method of claim 10, wherein:

the controller die includes a write enable pin and a data pin;

the memory die includes a test register coupled to the write enable pin and the data pin;

the method further comprises the following steps: the controller die sets the test register to a test enabled state via the write enable pin and the data pin; and is

Setting the isolation pin to the isolation state that isolates the memory die from the controller die after the test register is set to the test enable state.

12. The method of claim 10, wherein the package substrate further comprises a chip enable pin coupled to the memory die; and is

The method further comprises the following steps: the chip enable pin transmits a chip enable signal to the memory die for enabling the memory die.

13. The method of claim 10, wherein:

the package substrate further includes a test enable pin;

the method also includes setting the test enable pin to a test enabled state; and is

The memory die is configured to receive control via the test mode select pin, the test clock pin, and the test data pin when the isolation pin is set to the isolation state and the test enable pin is set to the test enable state.

14. The method of claim 10, wherein setting the memory die to receive control via the test mode select pin, the test clock pin, and the test data pin comprises:

setting the test mode select pin to switch an operating mode of the memory die;

setting the test clock pin to receive a test clock; and

the test data pin is set to perform data transfer.

15. The method of claim 14, wherein the data transfer is associated with a read access to the memory die.

16. The method of claim 14, wherein the data transfer is associated with a write access to the memory die.

Technical Field

The present invention relates to semiconductor testing, and more particularly, to a method of testing a memory device using a limited number of test pins and a memory device using the same.

Background

Non-volatile memory, such as flash memory, is widely used in communication and consumer electronic systems due to its compact physical size and reprogrammability. The reliability of non-volatile memories must be verified in factory testing to ensure that data can be reliably read from or written to the non-volatile memory. In practice, a non-volatile memory device, such as an embedded multimedia card (eMMC) or universal flash memory (UFS), may contain more than one memory unit that is only indirectly accessible via intermediate circuitry, such as a memory controller.

Therefore, a memory device and a test method thereof, which can directly access its memory cells from the outside, are required.

Disclosure of Invention

In one embodiment, a memory device includes a package substrate, a controller die, and a memory die. The package substrate includes an isolation pin, a test mode selection pin for switching an operation mode of the memory die, a test clock pin for receiving a test clock, and a test data pin for performing data transfer. The controller die is disposed on the package substrate and coupled to the isolation pins. A memory die is disposed on the package substrate and is coupled to the test mode select pin, the test clock pin, and the test data pin. The memory die is configured to receive control via the test mode select pin, the test clock pin, and the test data pin when the isolation pin is configured in an isolation state that isolates the memory die from the controller die.

In another embodiment, a memory device includes a package substrate, a controller die, and a memory die. The package substrate includes an isolation pin, a test enable pin, a test mode select pin for switching an operating mode of the memory die, a test clock pin for receiving a test clock, and a test data pin for performing data transfer. The controller die is disposed on the package substrate and coupled to the isolation pins. The memory die is disposed on the package substrate and is coupled to a test enable pin, a test mode select pin, a test clock pin, and a test data pin. The memory die is configured to receive control via the test mode select pin, the test clock pin, and the test data pin when the isolation pin is set in an isolation state that isolates the memory die from the controller die and the test enable pin is set in a test enabled state.

In yet another embodiment, a method is used for testing a memory device that includes a package substrate, a controller die, and a memory die. The package substrate includes an isolation pin, a test mode selection pin, a test clock pin, and a test data pin. The method comprises the following steps: setting an isolation pin to an isolation state, thereby isolating the memory die from the controller die; and setting the memory die to receive control via the test mode select pin, the test clock pin, and the test data pin when the isolation pin is set to the isolated state.

These and other objects of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiments, which are illustrated in the various drawing figures.

Drawings

The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the disclosure and to enable a person skilled in the pertinent art to make and use the disclosure.

FIG. 1 is a block diagram of a memory device according to an embodiment of the present invention.

Fig. 2 is a timing diagram of selected signals of the memory device of fig. 1.

Fig. 3 is a flow chart of a testing method suitable for use in the memory device of fig. 1.

FIG. 4 is a block diagram of another memory device according to an embodiment of the present invention.

Fig. 5 is a flow chart of a testing method suitable for use in the memory device of fig. 4.

Detailed Description

Fig. 1 is a block diagram of a memory device 1 according to an embodiment of the present invention. The memory device includes a package substrate 11, a controller die 10, and memory dies 121 to 12N, N being a positive integer, e.g., N-4 for 4 memory dies 121 to 124. The memory device 1 may be an embedded multimedia card (eMMC) device or a universal flash memory (UFS) device. The memory dies 121-12N may be NAND flash memory dies. The controller die 10 and the memory dies 121 through 12N may be fixed in a package and disposed on the package substrate 11. Package substrate 11 may include an isolation pin ISO, a test enable pin TE, a test chip enable pin CEt [1: N ], a test mode select pin MSt, a test clock pin CLKt, and a test data pin Dt for external test equipment to directly access memory dies 121-12N without passing through controller die 10. Controller die 10 may include chip enable pins CE [1: N ], write enable pins WE (1) through WE (N), read enable pins RE (1) through RE (N), data pins DQ (1) [7:0] through DQ (N) (7: 0), and other pins to access memory dies 121-12N. The controller die 10 may be coupled to the isolation pin ISO. Memory dies 121-12N may be coupled to test enable pin TE, test chip enable pin CEt [1: N ], test mode select pin MSt, test clock pin CLKi, and test data pin Dt on package substrate 11. In addition, each memory die 12N may be coupled to a chip enable pin CE [ N ], a write enable pin WE (N), a read enable pin RE (N), a data pin DQ (N) [7:0], and other pins of the controller 10, N being a positive integer and N ≦ N.

The memory device 1 may operate in a normal mode or a test mode. In the normal mode, the controller die 10 is coupled to each memory die 12n via a chip enable pin CE [ n ], a write enable pin WE (n), a read enable pin RE (n), a data pin DQ (n) [7:0], and other pins corresponding to the memory die 12n to control access to each memory die 12 n. In a test mode, the test equipment may set the isolation pin ISO to an isolated state, isolating each memory die 12n from the controller die 10 by disconnecting each memory die 12n from the chip enable pin CE [ n ], the write enable pin WE (n), the read enable pin RE (n), the data pin DQ (n) [7:0], and other pins of the controller die 10, and may set the test enable pin TE to a test enabled state for each memory die 12n to receive control directly from the test equipment via the test mode select pin MSt, the test clock pin CLKi, the test data pin Dt, and the test chip enable pin CEt [ n ]. In some embodiments, the isolation state may be a logic high level and the test enable state may be the logic high level. In some embodiments, test enable pin TE may be implemented through multi-die select pins MDS [3:0 ]. The multi-die select pins MDS [3:0] may be used to address the various memory dies 121-12N with unique addresses. In some embodiments, multi-die select pins MDS [3:0] may all be set to a logic high level to enable memory dies 121-12N for testing. Memory dies 121-12N may be tested in sequence by sequentially setting the respective test chip enable pins CEt [1: N ] to logic low levels.

Specifically, in the test mode, the test equipment may configure the test chip enable pins CEt [1: N ] to enable the respective memory dies 121 to 12N, configure the test mode select pin MSt to switch the operating mode of the respective memory dies 121 to 12N, configure the test clock pin CLKt to transmit a test clock to the respective memory dies 121 to 12N, and configure the test data pin Dt to perform data transmission on the respective memory dies 121 to 12N. The test chip enable pins CEt [1: N ] may be held at a logic high level, enabling the respective memory dies 121-12N. The data transfer may be associated with a read access or a write access to the respective memory dies 121-12N.

Fig. 2 shows a timing diagram of selected signals on isolation pin ISO, test enable pin TE, test mode select pin MSt, test clock pin CLKt, and test data pin Dt on package substrate 11. At time t1, isolation pin ISO and test enable pin TE are set to a logic high level by the test equipment, thereby setting memory die 12n to a test mode. At time t2, test mode select pin MSt receives a mode switch waveform from the test equipment indicating that mode switching of data transmission on test data pin Dt will begin next. The mode switching waveform received through the test mode select pin MSt may be a "high-low-high" pattern. At time t3, the test data pin Dt receives a mode code (M1, M2, M3) from the test equipment, while the test clock pin CLKi receives a clock signal for retrieving the mode code and performing a subsequent data transfer. The mode code (M1, M2, M3) is 3-bit data indicating a mode of a subsequent data transfer, for example, the mode code (0,0,1) may indicate a command mode, the mode code (0,1,0) may indicate an address mode, and the mode code (0,1,1) may indicate a data mode. In the case of a write access, at time t3, the mode code (M1, M2, M3) on the test data pin Dt may be (0,1,0) indicating that a subsequent data transfer will carry the write address, and at time t4, the test data pin Dt receives the 8-bit addresses B0 through B7 from the test equipment and transfers them to the memory die 12 n. At time t6, the test mode select pin MSt receives a mode switch waveform indicating another mode switch, and at time t7 the test data pin Dt receives a mode code (M1, M2, M3) indicating the next data access, e.g., a mode code (0,1,1) indicating that the subsequent data transmission will include data to be written. In some embodiments, if at time t6 no mode switching waveform is detected on the test mode select pin MSt, the test mode select pin MSt may continue to receive the next 8-bit address until a mode switching waveform is detected. In the case of a read access, at time t3, the mode code (M1, M2, M3) may be (0,1,0) indicating that the subsequent data transfer will include a read address, and at time t5, the test data pin Dt receives 8-bit data B0 through B7 from the memory die 12n and transfers it to the test equipment.

Fig. 3 is a flow chart of a test method 300 applicable to the memory device 1. The test method 300 comprises steps S302 and S304 for testing the memory dies 121 to 12N in the memory device 1, wherein step S302 is for isolating the memory dies 121 to 12N from the controller die 10 and step S304 is for setting the memory dies 121 to 12N into a test mode. Any reasonable variation or adjustment of steps is within the scope of the present disclosure. The following steps S302 and S304 are provided:

s302: at power up, the isolation pin ISO is set to an isolation state, thereby isolating the memory dies 121 to 12N from the controller die 10;

s304: test enable pin TE is set to a test enabled state to set memory dies 121-12N to receive control via test mode select pin MSt, test clock pin CLKi, and test data pin Dt.

Details of steps S302 and S304 are described in the preceding paragraphs and are not repeated here for the sake of brevity. In the test mode, the test equipment may sequentially set the chip enable pins CE [1: N ] to a logic low level while sequentially applying test patterns to the memory dies 121-12N and receiving test results from the memory dies 121-12N, thereby completing factory testing of a large number of memory dies in a thorough and efficient manner.

Memory device 1 and test method 300 implement a test mode using (5+ N) pins (isolation pin ISO, test enable pin TE, test chip enable pin CEt [1: N ], test mode select pin MSt, test clock pin CLKt, and test data pin Dt), which uses a limited number of test pins on the package of memory device 1, allows a large number of memory devices 1 to be tested simultaneously, and reduces the time required for factory testing.

Fig. 4 is a block diagram of another memory device 4 according to an embodiment of the present invention. The circuit configuration and operation of the memory device 4 are similar to those in the memory device 1 except that the test enable pin TE is omitted from the package substrate 41 and additional test registers 441 through 44N are employed in the respective memory dies 421 through 42N to set the test mode. The explanation of the isolation pin ISO, the test chip enable pins CEt [1: N ], the test mode select pin MSt, the test clock pin CLKi, the test data pin Dt, the chip enable pins CE [1: N ], the write enable pins WE (1) to WE (N), the read enable pins RE (1) to RE (N), and the data pins DQ (1) [7:0] to DQ (N) [7:0] is the same as in FIG. 1, and is omitted for the sake of brevity. The following explanation will focus on the circuit configuration and operation of the test registers 441 to 44N.

Controller die 10 may have internal or external memory that stores test firmware. The write enable pins WE (1) through WE (n) may be active low pins. At power up, the controller 10 may load test firmware from internal or external memory, set the write enable pins WE (1) through WE (N) to a logic low level, and write test enable status into the test registers 441 through 44N according to the test firmware and via the data pins DQ (1) [7:0] through DQ (N) [7:0 ]. The test enable state may be a logic high ("1") or a logic low ("0"), e.g., controller 10 may write a "1" to test registers 441-44N at a respective memory address. Once the setting of test registers 441-44N to the test enabled state is complete, isolation pin ISO may be set to the isolation state, thereby isolating memory dies 421-42N from controller die 10. In some embodiments, the isolation pin ISO may be set by the controller 10 according to test firmware. In other embodiments, the isolation pin ISO may be set by test equipment external to the memory device 1. Memory dies 421 through 42N may then read the test enable states from test registers 441 through 44N and enter a test mode in which memory dies 421 through 42N may receive control directly from the test equipment via test mode select pin MSt, test clock pin CLKi, test data pin Dt, and test chip enable pin CEt [1: N ]. The operation of the test mode select pin MSt, the test clock pin CLKi, and the test data pin Dt are similar to those in FIG. 2 and thus will not be repeated here.

The memory device 4 uses 1 less pin on the package substrate 41 to implement the test mode than the memory device 1, thereby further reducing the number of test pins on the package, allowing a large number of memory devices 4 to be tested simultaneously, and reducing the time required for factory testing.

Fig. 5 is a flow chart of a test method 500 applicable to the memory device 4. The test method 500 includes steps S502 to S506 for testing the memory dies 421 to 42N in the memory device 4, wherein step S502 is for setting the test registers 441 to 44N to a test enabled state, step S504 is for isolating the memory dies 421 to 42N from the controller die 10, and step S506 is for setting the memory dies 121-12N to a start test mode. Any reasonable variation or adjustment of steps is within the scope of the present disclosure. The following steps S502 to S506 are provided:

s502: at power up, controller die 10 sets test registers 441-44N to a test enable state via respective write enable pins WE (1) through WE (N) and data pins DQ (1) [7:0] through DQ (N) [7:0 ];

s504: setting isolation pin ISO to an isolation state, thereby isolating memory dies 421-42N from controller die 10;

s506: memory dies 421-42N determine that the respective test registers 441-44N are in a test enabled state and receive control via respective test mode select pin MSt, test clock pin CLKi, and test data pin Dt.

Details of steps S502 and S506 are described in the preceding paragraphs and are not repeated here for the sake of brevity. Method 500 does not set the test enable pins to a test enabled state as disclosed in method 300, but rather sets test registers 441 through 44N to a test enabled state, thereby providing test functionality while employing a further reduced number of test pins on the package.

The memory devices 1, 4 and the test methods 300, 500 implement a test mode using a limited number of test pins on the package, allowing a large number of memory devices 1, 4 to be measured simultaneously and reducing the time required for factory testing.

Those skilled in the art will readily recognize many modifications and variations that may be made to the devices and methods while following the teachings of the present invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.