KR20080052047A - Circuit and method for controlling read/write operation of semiconductor memory apparatus - Google Patents

Abstract

A circuit and a method for controlling read/write operation of a semiconductor memory apparatus are provided to improve test performance by preventing rapid increase of a transient current during data input or output operation. According to a circuit for controlling read/write operation of a semiconductor memory apparatus comprising a plurality of banks(30,40,50,60), a command decoder(10) outputs a read signal or a write signal by decoding a plurality of control signals corresponding to an external command. A control part(100) generates an enable signal to operate the plurality of banks with time difference, according to one of a test mode signal and an address signal and the read or write signal.

Description

Circuit and Method for Controlling Read / Write Operation of Semiconductor Memory Apparatus}

1 is a block diagram of a read / write operation control circuit of a semiconductor memory device according to the prior art;

2 is a block diagram of the controller of FIG. 1;

3 is a circuit diagram of an enable signal generator of FIG. 2;

4 is a timing diagram of a read operation of a semiconductor memory device according to the related art.

5 is a block diagram of a read / write operation control circuit of a semiconductor memory device according to the present invention;

6 is a block diagram of the controller of FIG. 5;

7 is a circuit diagram of an enable signal generator of FIG. 6;

8 is a timing diagram of a read operation of the semiconductor memory device according to the present invention.

<Description of Symbols for Main Parts of Drawings>

10: command decoder 20, 100: control unit

30 to 60: Bank 200: Enable signal generator

210: timing controller 220: enable signal output unit

230: signal input unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor memory devices, and more particularly, to a read / write operation control circuit and method of a semiconductor memory device for controlling timing of read and write operations of each memory bank (hereinafter, referred to as a bank).

As shown in FIG. 1, the read / write operation control circuit of a semiconductor memory device according to the related art includes a command decoder 10, a controller 20, and a plurality of banks 30 to 60. The number of the plurality of banks 30 to 60 depends on the memory capacity of the semiconductor memory device, and FIG. 1 shows an example of four banks.

The command decoder 10 may include a chip selection signal (CS), a column address strobe signal (CAS), a row address strobe signal (RAS), and a write enable signal ( Write enable signal (WE) is decoded and the operation command signal is output. For example, when the CS, CAS, RAS, and WE are input as a logic value suitable for a read or write command, the command decoder 10 decodes the combination of the CS, CAS, RAS, and WE to read the signal (iRDP) or The write signal iWTP is output.

As illustrated in FIG. 2, the controller 20 includes a signal processor 21 and an enable signal generator 22.

The signal processor 21 outputs a column selection signal YSP having the same timing as the read signal iRDP or the write signal iWTP, and performs a read or write operation among the addresses ADD <0:15>. The bank select signals BBY <0: 3> are output in accordance with ADD <14:15> which defines the bank.

The enable signal generator 22 generates an enable signal (YAE <0: 3>) that allows the plurality of banks 30 to 60 to receive an address using the column select signal YSP. do. The enable signal generator 22 transfers the enable signal YAE <0: 3> to a bank selected according to the bank selection signal BBY <0: 3> among the plurality of banks 30 to 60. By input, the bank is configured to receive an address and perform a read or write operation.

As shown in FIG. 3, the enable signal generator 22 commonly receives the column selection signal YSP at a first input terminal, and applies the bank selection signals BBY <0: 3> to a second input terminal. A first signal configured to receive the first to fourth NAND gates ND1 to ND4 and the outputs of the first to fourth NAND gates ND1 to ND4, respectively, to generate an enable signal YAE <0: 3>. First to fourth inverters IV1 to IV4 are provided.

The operation of the read / write operation control circuit of the semiconductor memory device according to the related art, which is configured as described above, is as follows.

The command decoder 10 decodes the combination of CS, CAS, RAS, and WE to output a read signal iRDP or a write signal iWTP.

The signal processor 21 of the controller 20 outputs a column select signal YSP having the same timing as the read signal iRDP or the write signal iWTP, and among the addresses ADD <0:15>. The bank selection signals BBY <0: 3> are output according to ADD <14:15> which defines a bank in which a read or write operation is to be performed. In the test mode, all bank selection signals BBY <0: 3> are activated and output regardless of the ADD <14:15>.

The enable signal generator 22 of the controller 20 transmits the column selection signal YSP to a bank selected according to the bank selection signals BBY <0: 3> among the plurality of banks 30 to 60. The enable signal (YAE <0: 3>) generated by using this function is output.

In the case of a read operation, a bank in which the enable signal YAE <0: 3> activated to the one of the plurality of banks 30 to 60 is activated receives and decodes the address ADD <0:15>. Data of the cell corresponding to the decoding result is read and output to the outside of the semiconductor memory device through the data lines GIO <0: 3>.

Meanwhile, in the write operation, a bank in which the enable signal YAE <0: 3> activated to the one of the plurality of banks 30 to 60 is activated receives the address ADD <0:15>. Decoded data is written outside the semiconductor memory device through the data lines GIO <0: 3> in a cell corresponding to the decoding result.

The operation of the semiconductor memory device may be classified into a normal mode and a test mode. The test mode is a mode for operating in accordance with a predetermined test condition in order to check an operation abnormality of the semiconductor memory device. The test mode is not a normal mode. There are several types of test modes, among which are parallel test modes. The parallel test mode is a test mode in which data having the same logic value is written in parallel to the data pin of the semiconductor memory device and read again in parallel to test whether data write and read operations are performed normally. The parallel test mode is a test mode that is widely used because it can reduce the test progress time.

In the read or write operation according to the normal mode described above, only one of the bank selection signals BBY <0: 3> is activated, and thus only one of the enable signals YAE <0: 3> is also activated. For example, when the enable signal YAE <0> is activated, the bank 0 30 of the plurality of banks 30 to 60 performs a read or write operation.

On the other hand, in the case of the read operation according to the test mode, for example, the parallel test mode, all of the bank selection signals BBY <0: 3> are activated at the same timing. Therefore, as shown in FIG. 4, since the enable signals YAE <0: 3> are all activated at the same timing, the plurality of banks 30 to 60 simultaneously perform a read operation so that the data lines GIO <0: 3> are simultaneously read. The data is output at the same timing. In the case of the write operation according to the parallel test mode, the plurality of banks 30 to 60 simultaneously perform the write operation, and data input is performed at the same timing through the data lines GIO <0: 3>.

The read / write operation control circuit of the semiconductor memory device according to the related art has the following problems because all banks operate simultaneously and data is input or output.

First, all banks operate simultaneously to rapidly increase the amount of current consumed at the timing of data input or output, thereby increasing the total current consumption.

Secondly, all banks operate simultaneously to allow data to be input or output, resulting in instantaneous current surges that can cause test errors.

An object of the present invention is to provide a read / write operation control circuit and method for a semiconductor memory device capable of reducing current consumption.

Another object of the present invention is to provide a read / write operation control circuit and method for a semiconductor memory device capable of preventing noise.

The read / write operation control circuit of a semiconductor memory device according to the present invention is a read / write operation control circuit of a semiconductor memory device having a plurality of banks, and decodes a plurality of control signals corresponding to an external command to read or write a signal. A command decoder for outputting the; And a controller configured to generate an enable signal for operating the plurality of banks at a time difference according to one of a test mode signal and an address signal and the read or write signal.

The read / write operation control method of a semiconductor memory device according to the present invention is a read / write operation control method of a semiconductor memory device having a plurality of banks, and decodes a plurality of control signals according to an external command to decode a read signal or a write signal. Generating; And activating the plurality of banks at a time difference according to any one of a test mode signal and the read signal or the write signal to perform a read or write operation.

Hereinafter, exemplary embodiments of a read / write operation control circuit and method of a semiconductor memory device according to the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 5, the read / write operation control circuit of the semiconductor memory device according to the present invention decodes a plurality of control signals corresponding to an external command and outputs a read signal iRDP or a write signal iWTP. The plurality of banks 30 to 60 may be connected according to the decoder 10 and one of the test mode signal TPARA and the address signal ADD <14:15> and the read signal iRDP or the write signal iWTP. The control unit 100 generates an enable signal YAE <0: 3> for operation with a parallax.

The plurality of control signals include a chip selection signal (CS), a column address strobe signal (CAS), a row address strobe signal (RAS), and a write enable signal (Write). Enable Signal: WE).

As illustrated in FIG. 6, the controller 100 generates a column select signal YSP using the read signal iRDP or the write signal iWTP, and generates the address signal ADD <14:15>. The signal processor 21 generates a plurality of bank selection signals BBY <0: 3> and delays the column selection signal YSP by different times according to the test mode signal TPARA. The enable signal generator 200 outputs a plurality of enable signals YAE <0: 3> corresponding to the respective bank selection signals BBY <0: 3>.

As shown in FIG. 7, the enable signal generator 200 delays and outputs the column selection signal YSP by a different time according to the test mode signal TPARA. An enable signal output unit 220 for outputting the output of the timing controller 210 as the plurality of enable signals YAE <0: 3> according to a plurality of bank selection signals BBY <0: 3>; And a signal input unit 230 for inputting the test mode signal TPARA and the column selection signal YSP to the timing controller 210. When the test mode signal TPARA is activated, that is, when the test mode signal TPARA is activated, the enable signal generator 200 receives a plurality of enable signal YAE <0: 3. >), And when the test mode signal TPARA is deactivated, that is, in the normal mode, the column selection signal YSP is selected from among the plurality of bank selection signals BBY <0: 3>. And to output an enable signal corresponding to the signal.

The timing controller 210 outputs one of the column selection signal YSP or the column selection signal YSP delayed by each delay time according to the test mode signal TPARA. And 211 to 214. The first timing control logic circuit 211 may receive a first NAND gate ND1 and a column for receiving the column selection signal YSP at a first input terminal and an inverted test mode signal TPARA at a second input terminal. A second NAND gate receiving the first delay De_t0 receiving the selection signal YSP, the output of the first Delay_t0 at the first input, and the test mode signal TPARA at the second input; ND12 and a third NAND gate ND13 that receives an output of the first NAND gate ND11 and an output of the second NAND gate ND12. The second to fourth timing control logic circuits 212 to 214 are configured in the same manner as the first timing control logic circuit 211. However, delay times of the first to fourth delays Delay_to to Delay_t3 of the first to fourth timing control logic circuits 211 to 214 are different from each other, and a delay time of each of the first to fourth delays Delay_to to Delay_t3 is different. When t0 to t3, t0 <t1 <t2 <t3.

The signal output unit 220 logically multiplies each of the plurality of bank selection signals BBY <0: 3> and the output of the timing controller 210 to the plurality of enable signals YAE <0: 3>. First to fourth signal output logic circuits 221 to 224. The first signal output logic circuit 221 receives an output of the timing controller 210 at a first input terminal and corresponds to one of the plurality of bank selection signals BBY <0: 3> at a second input terminal. NAND gate ND31 that receives (BBY <0>), and an output of the NAND gate ND31 are inverted to one of the plurality of enable signals YAE <0: 3>. An inverter IV31 for outputting is provided. The second to fourth signal output logic circuits 222 to 224 are configured in the same manner as the first signal output logic circuit 221.

The signal input unit 230 receives a signal line for inputting the column selection signal YSP to the timing controller 210, a test mode signal TPARA, and inverts the input signal to the timing controller 210. An inverter IV11 and a second inverter IV12 configured to receive and invert an output of the first inverter IV11 and to be input to the timing controller 210 are provided.

The operation of the read / write operation control circuit of the semiconductor memory device according to the present invention configured as described above is as follows.

First, the read or write operation in the normal mode will be described.

The command decoder 10 decodes the combination of CS, CAS, RAS, and WE to output a read signal iRDP or a write signal iWTP.

The signal processor 21 of the controller 100 outputs a column select signal YSP having the same timing as the read signal iRDP or the write signal iWTP, and reads from the addresses ADD <0:15>. Alternatively, the bank select signal BBY <0: 3> is output according to ADD <14:15> which defines a bank in which the write operation is to be performed.

In the normal mode, the test mode signal TPARA is inactivated to a low level.

The enable signal generation unit 200 of the controller 100 transmits the column selection signal YSP to a bank selected according to the bank selection signals BBY <0: 3> among the plurality of banks 30 to 60. The enable signal (YAE <0: 3>) generated without delay is output.

Since the test mode signal TPARA is at a low level, the signal input unit 230 of the enable signal generator 200 outputs a high level signal through the first inverter IV11 and through the second inverter IV12. Output a low level signal.

Since the first NAND gate ND11 of the first timing control logic circuit 211 of the timing controller 210 receives a high level signal from the signal input unit 230 at a second input terminal, it operates as an inverter to select the column. The signal YSP is inverted and output to the third NAND gate ND13. Since the second NAND gate ND12 receives a low level signal from the signal input unit 230 at a second input terminal, a high level signal is transferred to the third NAND gate ND13 regardless of the signal level of the first input terminal. Output Since the third NAND gate ND13 receives a high level signal from the second NAND gate ND12 at a second input terminal, the third NAND gate ND13 operates as an inverter, thereby inverting the output of the first NAND gate ND11, thereby providing a first delay ( Delay_t0) outputs a column selection signal YSP having an original phase without being delayed.

Since the second to fourth timing control logic circuits 212 to 214 of the timing controller 210 are configured in the same manner as the first timing control logic circuit 211, the same as the first timing control logic circuit 211. Operation is performed to output the column selection signal YSP having the original phase without being delayed through each of the delays Delay_t0 to Delay_t3.

The first to fourth signal output logic circuits 221 to 224 of the signal output unit 220 may apply the column selection signal YSP only when the bank selection signals BBY <0: 3> input thereto are activated. Is output as an enable signal (YAE <0: 3>). For example, if only BBY <0> is activated among the bank selection signals BBY <0: 3>, the first signal output logic circuit 221 activates and outputs YAE <0>, and outputs second to fourth signals. Logic circuits 222 to 224 deactivate YAE <1: 3> to output.

In the read operation according to the normal mode, the bank in which the enable signal YAE <0: 3> input to the one of the plurality of banks 30 to 60 is activated is the address ADD <0:15>. Receives and decodes the data, reads data of a cell corresponding to the decoding result, and outputs the data to the outside of the semiconductor memory device through the data lines GIO <0: 3>.

Meanwhile, in the write operation according to the normal mode, the bank in which the enable signal YAE <0: 3> input to the one of the plurality of banks 30 to 60 is activated is the address ADD <0:15. >) Receives and decodes the data, and writes data input from the outside of the semiconductor memory device through the data lines GIO <0: 3> to the cell corresponding to the decoding result.

Next, the read or write operation in the test mode will be described. The test mode is a mode for operating in accordance with a predetermined test condition in order to check an operation abnormality of the semiconductor memory device. The test mode is not a normal mode. There are several types of test modes, among which are parallel test modes. The parallel test mode is a test mode in which data having the same logic value is written in parallel to the data pin of the semiconductor memory device and read again in parallel to test whether data write and read operations are performed normally. The parallel test mode is a test mode that is widely used because it can reduce the test progress time.

The command decoder 10 decodes the combination of CS, CAS, RAS, and WE to output a read signal iRDP or a write signal iWTP.

The signal processor 21 of the controller 100 outputs the column select signal YSP having the same timing as the read signal iRDP or the write signal iWTP, and all of the signals are irrespective of ADD <14:15>. The bank selection signals BBY <0: 3> are activated and output.

In the test mode, the test mode signal TPARA is activated to a high level.

An enable signal generated by the enable signal generator 200 of the controller 100 by delaying the column select signal YSP by the different times to the plurality of banks 30 to 60. Output>)

Since the test mode signal TPARA is high level, the signal input unit 230 of the enable signal generator 200 outputs a low level signal through the first inverter IV11 and through the second inverter IV12. Output a high level signal.

Since the first NAND gate ND11 of the first timing control logic circuit 211 of the timing controller 210 receives a low level signal from the signal input unit 230 at a second input terminal, the column select signal YSP Irrespective of this, a high level signal is output to the third NAND gate ND13. Since the second NAND gate ND12 receives a high level signal from the signal input unit 230 at a second input terminal, the second NAND gate ND12 operates as an inverter to invert the column selection signal YSP delayed through the first delay Delay_t0. Output to the third NAND gate ND13. Since the third NAND gate ND13 receives a high level signal from the first NAND gate ND11 at a first input terminal, the third NAND gate ND13 operates as an inverter to invert the output of the second NAND gate ND12 to invert the output of the first delay. The column select signal YSP is delayed by the delay time Delay_t0 and has an original phase.

Since the second to fourth timing control logic circuits 212 to 214 of the timing controller 210 are configured to be the same as the first timing control logic circuit 211, they are the same as the first timing control logic circuit 211. In this case, the column select signal YSP is delayed by the delay time of each delay Delay_t0 to Delay_t3 and has an original phase.

Since the first to fourth signal output logic circuits 221 to 224 of the signal output unit 220 are all of the bank selection signals BBY <0: 3> input thereto, the timing controller 210 may be activated. As shown in FIG. 8, the column selection signal YSP output from the first to fourth timing control logic circuits 211 to 214 of FIG. 8 is output as an enable signal YAE <0: 3>, which is activated at a predetermined time difference. .

In the case of the read operation according to the test mode, the plurality of banks 30 to 60 may be connected to the address ADD <0:15> according to the enable signal YAE <0: 3> which is activated at the predetermined time difference. Receives and decodes the data, reads data of a cell corresponding to the decoding result, and outputs the data with a predetermined time difference through the data lines GIO <0: 3> as shown in FIG.

On the other hand, in the write operation according to the test mode, the plurality of banks 30 to 60 are connected to the address ADD <0:15 according to the enable signal YAE <0: 3> which is activated at the predetermined time difference. >) Is input and decoded, and data input from the outside of the semiconductor memory device through the data lines GIO <0: 3> is written in a cell corresponding to the decoding result. In the write operation according to the test mode, data is simultaneously input through the data lines GIO <0: 3>, but is input according to the enable signal YAE <0: 3> which is activated at the predetermined time difference. Data is recorded with a parallax, and the present invention is a key technique for activating the enable signals YAE <0: 3> with a predetermined parallax.

As those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features, the embodiments described above should be understood as illustrative and not restrictive in all aspects. Should be. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

The read / write operation control circuit and method of the semiconductor memory device according to the present invention have the following effects.

First, since all banks operate with a predetermined time difference during the test mode, the amount of current consumed instantaneously during data input or output is reduced to reduce the total current consumption.

Second, since all banks operate with a predetermined time difference when the test mode is performed, instantaneous current surge does not occur during data input or output, thereby preventing noise, thereby improving test performance.

Claims (14)

A read / write operation control circuit of a semiconductor memory device having a plurality of banks, A command decoder configured to output a read signal or a write signal by decoding a plurality of control signals corresponding to an external command; And And a control unit for generating an enable signal for operating the plurality of banks at a time difference according to one of a test mode signal and an address signal and the read or write signal. The method of claim 1, The control unit A signal processing unit generating a column selection signal using the read signal or the write signal and generating a plurality of bank selection signals according to the address signal; And an enable signal generator configured to delay the column select signal by a different time according to the test mode signal and output a plurality of enable signals corresponding to the plurality of bank select signals, respectively. Lead / light operation control circuit. The method of claim 2, The enable signal generator Output a column selection signal delayed by a different time when the test mode signal is activated as a plurality of enable signals, and output the column selection signal as the plurality of enable signals when the test mode signal is deactivated. A read / write operation control circuit of a semiconductor memory device. The method of claim 2, The enable signal generator A timing controller configured to delay and output the column selection signal by a different time according to the test mode signal; An enable signal output unit configured to output the output of the timing controller as the plurality of enable signals according to the plurality of bank selection signals; And a signal input unit configured to input the test mode signal and the column selection signal to the timing controller. The method of claim 4, wherein The timing controller And a plurality of timing control logic circuits for outputting one of the column selection signal or a column selection signal delayed by a respective delay time according to the test mode signal. The method of claim 5, wherein The timing control logic circuit A first logic element receiving the column selection signal at a first input terminal and an inverted test mode signal at a second input terminal, A delay element receiving the column selection signal; A second logic element receiving an output of the delay element at a first input terminal and receiving the test mode signal at a second input terminal; and And a third logic element configured to receive an output of the first logic element and an output of the second logic element. The method of claim 4, wherein The signal output unit And a plurality of signal output logic circuits for logically multiplying each of the plurality of bank selection signals and the output of the timing controller to output the plurality of enable signals. The method of claim 7, wherein The signal output logic circuit A logic element receiving an output of the timing controller at a first input terminal and receiving one of the bank selection signals at a second input terminal; and And an inverting element for inverting an output of the logic element and outputting one of the plurality of enable signals. The method of claim 4, wherein The signal input unit A signal line for inputting the column selection signal to the timing controller; A first inverting device receiving the test mode signal and inputting the test mode signal to the timing controller; And a second inverting element which receives the output of the first inverting element and inputs it to the timing controller. The method according to any one of claims 1, 2, 3, 4, 5, 6, or 9, And the test mode signal is a signal generated according to a test mode for simultaneously inputting data having the same logic value to a data input / output pin of the semiconductor memory device. The method according to claim 1 or 2, The address signal is a read / write operation control circuit of a semiconductor memory device, characterized in that part of the address signal input from outside the semiconductor memory device associated with the bank selection. A read / write operation control method of a semiconductor memory device having a plurality of banks, Generating a read signal or a write signal by decoding a plurality of control signals according to an external command; And And performing a read or write operation by activating the plurality of banks at a time difference according to one of a test mode signal and the read signal or the write signal. The method of claim 12, The step of activating the plurality of banks with a time difference to perform a read or write operation And performing one of the test mode signal, the read signal, and the write signal when the test mode signal is activated. The method of claim 12, And performing a read or write operation by activating only selected banks of the plurality of banks when the test mode signal is deactivated and any one of the read signal or the write signal is activated. / Light behavior control method.

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