KR101062725B1 - Mode Selection Circuits and Methods for Memory Devices - Google Patents

Abstract

 The present invention relates to a mode selection circuit for a memory device that enables the operation mode to be changed only by the test mode in the packaged memory device. The circuit includes: first and second switching units connected to X4 and X8 bonding pads, respectively, and receiving X4 and X8 test mode entry signals, respectively; First and second buffers connected to the output terminals of the first and second switching units and outputting an X4 mode entry signal and an X8 mode entry signal, respectively; And an OR means connected to output terminals of the first and second buffers to output an X16 mode entry signal, wherein the X4 test mode or the X8 test mode in the X16 mode in which the X4 and X8 bonding pads are connected to ground (VSS). When the entry signal is enabled, it is switched to the X4 mode or the X8 mode.

Description

Circuit selection mode and method for memory devices {Circuit of mode selection for memry device}

1 is a mode selection circuit for a conventional memory device.

2 is a mode selection circuit for a memory device according to the present invention;

3 is a table of operating modes according to bonding options of an X4 bonding pad and an X8 bonding pad.

4 is a mode selection circuit diagram for a memory device according to another embodiment of the present invention.

* Names of symbols for main parts of the drawings

200: X4 bonding pad 210: X8 bonding pad

220: first switching unit 230: second switching unit

240: third buffer 250: fourth buffer

260: first orphan means

The present invention relates to a mode selection circuit and a method for a memory device, and more particularly, to a mode selection circuit and a method for a memory device that enables the operation mode to be changed only by the test mode in the packaged memory device.

In general, in the case of DRAM, the output data is made in the form of X4, X8, X16, and X32 mode depending on how many bits are output in the same cycle in consideration of the memory usage. In particular, DDR (Double Date Rate) SDRAM in X16 mode is used for ultra high speed memory, and X8 mode is often used as main memory by being assembled into memory modules.

On the other hand, this type of classification is made by the fact that the use of the column address is actually different with respect to the use of the address. In terms of structure, the packaging pad is determined by determining the X16, X8, and X4 modes using a bonding pad.

In this regard, Fig. 1 shows a conventional mode selection circuit for a memory device.

Conventional mode selection circuit is connected to the X4 bonding pad 100 and the X8 bonding pad 110, respectively, the first and second antistatic parts (101, 111) for protecting the internal circuit from external electrical influences including static electricity, A first buffer 120 connected to an output node of the first antistatic unit 101 to output an X4 operation mode signal, and a first node connected to an output node of the second antistatic unit 111 to output an X8 operation mode signal; Two buffers 130, and OR means 140 for receiving the X4 and X8 operating mode signals and outputting the X16 mode operating signals.

The conventional mode selection circuit having the configuration as described above is connected to the X4 bonding pad 100 and the X8 bonding pad 110 at the time of package manufacture, that is, with the internal voltage VDD or the ground VSS. Depending on the connection state, a particular mode of operation is determined. In addition, since one memory supports two or more operation modes, it is necessary to verify whether the operation of the memory determined as the X16 mode has a specific effect on the X4 and X8 operation modes. However, in the related art, in order to change the operation mode of the memory in which the package is completed, the package must be removed, the bonding wires already connected must be removed, and the connection state of the bonding pads must be changed. There is a case that does not operate, and also, there is a problem that takes a lot of time, equipment and manpower to change the operation mode.

Accordingly, the present invention was created to solve the problems inherent in the prior art as described above, and an object of the present invention is to use a test mode entry signal, thereby enabling a mode of a memory device to be switched without modifying a bonding option. A mode selection circuit and method for a memory device is provided.

In order to achieve the above object, in accordance with an aspect of the present invention, there is provided a mode selection circuit for a memory device, the circuit being connected to an X4 and X8 bonding pad, respectively, and receiving a first X4 and X8 test mode entry signal, respectively. And a second switching unit; First and second buffers connected to the output terminals of the first and second switching units and outputting an X4 mode entry signal and an X8 mode entry signal, respectively; And an OR means connected to output terminals of the first and second buffers to output an X16 mode entry signal, wherein the X4 test mode or the X8 test mode in the X16 mode in which the X4 and X8 bonding pads are connected to ground (VSS). When the access signal is enabled, it is characterized in that the conversion to the X4 mode or X8 mode.

According to another aspect of the invention, the first and second switching unit, the transmission means for receiving a signal transmitted from the X4 and X8 bonding pads, X4 and X8 test mode entry signal, respectively; A switch means connected to an internal voltage VDD and receiving the X4 and X8 test mode entry signals, respectively, when the X4 and X8 test mode entry signals are disabled, the switch means is turned off, and The transfer means transfers the signal transmitted from the X4 bonding pad to the first and second buffers, respectively, and when the X4 or X8 test mode entry signal is enabled, the switch means is turned on and the internal voltage VDD ) Is delivered to the first or second buffer, respectively.

According to one aspect of the present invention, there is provided a mode selection method for a memory device, the method comprising: connecting the X4 and X8 bonding pads to ground to operate the memory device in X16 mode;

Applying an X4 or X8 test mode entry signal to the memory device operating in the X16 mode; And

And switching the memory device from the X16 mode to the X4 or X8 mode by the X4 or X8 test mode entry signal, respectively.

According to one aspect of the present invention, there is provided a mode selection method for a memory device, the method comprising: (a) enabling a first test mode entry signal to operate in an X4 mode; (b) enabling the second test mode entry signal to operate in the X8 mode; And (c) disabling the first and second test mode entry signals to operate in the X16 mode.

According to another aspect of the present invention, only one of the steps (a) to (c) is selected.

(Example)

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 shows a mode selection circuit for a memory device according to the present invention.

The mode selection circuit for the memory device according to the present invention may be connected to the X4 bonding pads and the X8 bonding pads 200 and 210, respectively, to protect the internal circuits from external electrical influences including static electricity. ) And the first and second switching units 220 and 230, the first and the second switches connected to the output terminals of the third and fourth antistatic parts 201 and 211 and receiving the X4 and X8 test mode entry signals tm_X4 and tm_X8, respectively. The third and fourth buffers 240 and 250 and the output terminals of the third and fourth buffers 240 and 250, respectively, connected to the output terminals of the second switching units 220 and 230, respectively, to output the X4 mode and X8 mode entry signals X4 and X8. And first first means 260 which is connected to and outputs an X16 mode entry signal X16.

The first and second switching units 220 and 230 receive the signals transmitted from the third and fourth static electricity preventing units 201 and 211 and the X4 and X8 test mode entry signals tm_X4 and tm_X8, respectively. And switch means 221 and 231 connected to the internal voltage VDD and receiving the X4 and X8 test mode entry signals tm_X4 and tm_X8, respectively.

The transmission means 270 and 280 are inverters which receive the transmission gates 271 and 281 and X4 and X8 test mode entry signals tm_X4 and tm_X8, respectively, which pass signals transmitted from the third and fourth antistatic parts 201 and 211, respectively. 270 and 280.

The switch means (221, 231) has PMOS transistors (221, 231) provided between the output node of the transfer means (270, 280) and the internal voltage (VVD), and the X4 and X8 test mode entry signals to the gate terminals of the PMOS transistors (221, 231). Receive (tm_X4, tm_X8) respectively. The third and fourth buffers 240 and 250 are inverter chains formed of an even number of inverters 241, 242, 251 and 252.

Hereinafter, the operation of the mode selection circuit for a memory device according to the present invention will be described with reference to FIGS. 2 and 3.

3 shows an operation mode table according to bonding options of the X4 bonding pad and the X8 bonding pad.

As shown, the mode switching circuit for a memory device according to the present invention performs the same operation as the prior art until the X4 and X8 test mode entry signals tm_X4 and tm_X8 are enabled. More specifically, when the X4 and X8 bonding pads 200 and 210 of the memory device are connected to the ground (VSS) and operating in the X16 mode, the X4 and X8 test mode entry signals tm_X4 and tm_X8 are disabled (low). Level), the switch means 221, 231 are turned off. In this case, the transfer means 270 and 280 transfer the signals transmitted from the X4 bonding pads and the X8 bonding pads 200 and 210 to the third and fourth buffers 240 and 250, respectively, thereby maintaining the existing X16 mode.

After that, when the X4 or X8 test mode entry signals tm_X4 and tm_X8 are enabled (high level), the switch means 221 and 231 are turned on, and the internal voltage VDD is transferred to the third or fourth buffers 240 and 250. Each is transferred to switch the memory device to X4 mode or X8 mode.

4 illustrates a mode selection circuit for a memory device according to another embodiment of the present invention.

The mode selection circuit for a memory device according to another exemplary embodiment of the present invention may include second and third switches instead of the first and second switching units 220 and 230 and the third and fourth buffers 240 and 250 of the previous embodiment shown in FIG. 2. Ora means (290, 300). The second and third orphan means 290 and 300 receive the signals transmitted from the X4 bonding pads and the X8 bonding pads 200 and 210 and the X4 and X8 test mode entry signals tm_X4 and tm_X8, respectively, to thereby perform the same operation as the previous embodiment. Perform.

As described above, the mode selection circuit for a memory device according to the present invention, in the X16 mode in which the X4 bonding pads and the X8 bonding pads 200 and 210 are connected to the ground (VSS), does not require modification of the bonding option X4 or X8. By enabling the test mode entry signals tm_X4 and tm_X8, the memory device may be switched to the X4 mode or the X8 mode.

According to the configuration as described above of the present invention, in the packaged memory device, by changing the operation mode only by the test mode entry signal, damage to the product, time, equipment and manpower caused when changing the connection state of the bonding pads It can prevent the disturbance.

While the invention has been shown and described with reference to certain preferred embodiments, the invention is not so limited, and the invention is not limited to the spirit and scope of the invention as set forth in the following claims. It will be readily apparent to those skilled in the art that these various modifications and variations can be made.

Claims (5)

In the mode selection circuit for a memory device, X4 and X8 bonding pads, respectively, connected to the transmission means for receiving signals transmitted from the X4 and X8 bonding pads and X4 and X8 test mode entry signals input from the outside, and an internal voltage (VDD), respectively. And first and second switching units including switch means for receiving an X8 test mode entry signal, respectively. First and second buffers connected to the output terminals of the first and second switching units and outputting an X4 mode entry signal and an X8 mode entry signal, respectively; And An ore means connected to the output terminals of the first and second buffers to output an X16 mode entry signal, And when the X4 or X8 test mode entry signal is enabled in the X16 mode in which the X4 and X8 bonding pads are connected to the ground (VSS), the mode selection circuit for the memory device. Claim 2 has been abandoned due to the setting registration fee. The method of claim 1, When the X4 and X8 test mode entry signals are disabled, the switch means is turned off and at the same time the transfer means transfers the signals transmitted from the X4 and X8 bonding pads to the first and second buffers, respectively. When the X4 or X8 test mode entry signal is enabled, the mode selection circuit for the memory device, wherein the switch means is turned on and the internal voltage VDD is transmitted to the first or second buffer, respectively. . In the mode selection method for a memory device, Operating the memory device in X16 mode by connecting the X4 and X8 bonding pads to ground and outputting an internal voltage when the X4 and X8 test mode entry signals are input from the outside; Applying the X4 or X8 test mode entry signal to the memory device operating in the X16 mode; And And when the X4 or X8 test mode entry signal is enabled, outputting a signal input from the X4 and X8 bonding pads to switch the memory device from the X16 mode to the X4 or X8 mode, respectively. How to choose mode. delete delete

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