KR19990061047A - Semiconductor memory device and signal coding method - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal transmission circuit of a semiconductor memory, and in particular, when a signal is transmitted using a load path having a large load such as an address or an input / output in a chip, one transmission path may be changed by different pulse widths applied to the transmission path. In the semiconductor memory device, multiple signals are transmitted to one transmission path 20 in order to reduce the number of transmission paths and thereby reduce chip size and reduce current by transmitting several signals at the same time. Transmitter 10 for transmitting in a pulse state having a different width according to the state; In the semiconductor memory device and the signal coding method of the signal coding method using a pulse width provided to the receiving unit 30 for receiving a signal of a different state transmitted through the transmission path 20 to decode the original signal It is about.

Description

Semiconductor memory device and signal coding method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal transmission circuit of a semiconductor memory, and in particular, when a signal is transmitted using a load path having a large load such as an address or an input / output in a chip, one transmission path may be changed by different pulse widths applied to the transmission path. The present invention relates to a semiconductor memory device and a signal coding method for reducing the number of transmission paths, thereby reducing chip size and reducing current, by transmitting several signals at the same time.

Taking a conventional DRAM as an example, when using 16 inputs / outputs, a transmission path of at least 16 data lines is required in a peripheral area.

In this case, 16 transmission paths generate pulses each time I / O is accessed, or 16 transmission paths perform level transitions depending on the latch circuit. Current consumption.

Therefore, the present invention was devised to solve the above-mentioned problems. The pulse width applied to the transmission path when the signal is transmitted using a transmission path with a large load such as an address or an input / output in the chip is determined. The present invention provides a semiconductor memory device and a signal coding method thereof in which multiple signals are transmitted at the same time through different transmission paths, thereby reducing the number of transmission paths, thereby reducing chip size and reducing current. The purpose is.

1 is a block diagram of a semiconductor memory device using a pulse width according to the present invention;

2A to 2H are input / output pulse timing diagrams of FIG. 1.

Explanation of symbols for main parts of the drawings

10: transmitter 20: transmission path

30 receiver 11 pulse width controller

12 pulse generator 31 pulse rising edge detector

32: N-pulse generator 33: pulse decoder

In accordance with another aspect of the present invention, there is provided a semiconductor memory device comprising: a transmitter (10) for transmitting a plurality of signals to one transmission path (20) in pulse states having different widths according to states; It is characterized in that the signal coding using the pulse width is provided by the receiving unit 30 for receiving a signal of different states transmitted through the transmission path 20 to decode the original signal.

In addition, the present invention for achieving the object as described above, in the signal coding method of the semiconductor memory device, the process of selecting the width of the pulse to be output according to the state of the signal to be transmitted to one of n different types and ; Applying a pulse of a selected width to the transmission line in accordance with the reference clock; Reading the time point of the pulse received through the transmission path and outputting the internal reference clock of the receiver; Outputting a decoding pulse for delaying the internal reference clock of the receiver by an amount equal to the delay amount for controlling the pulse width used by the pulse width controller of the transmitter; And comparing the signals received through the decoding pulse output and the transmission path output in the above process to separate and output the n different states.

As shown in FIG. 1, the transmitter 10 includes: a pulse width controller 11 for selecting one of n different types of pulse widths to be output according to a state of a signal to be transmitted; And a pulse generator 12 for applying the pulse width of the width selected by the pulse width controller 11 to the transmission line 20 in accordance with the reference clock.

As shown in FIG. 1, the receiver 30 includes: a pulse rising edge detector 31 for reading a time point of a received pulse and outputting a receiver internal reference clock; N-pulse outputting a decoding pulse delaying the internal reference clock output from the pulse rising edge detector 31 by the same amount as the pulse width control delay amount used by the pulse width controller 11 of the transmitter 10. Generator 32; And a pulse decoder 33 for comparing the output of the N-pulse generator 32 and the signal received through the transmission path 20 to separate and output n different states.

The operation principle according to the present invention will be described in detail as follows.

In the present invention, a plurality of signals are coded and transmitted in one transmission path 20. As a method of coding, a width of a pulse to be transmitted is changed according to a signal code.

An example of transmitting two signals through one transmission path 20 will be described.

When two signals S0 and S1 are transmitted to one transmission path 20, input / output signals of the transmitter 10 and the receiver 30 may be defined as shown in the following table.

S1 S0 I / O L L S01_0 L H S01_1 H L S01_2 H H S01_3

First, the pulse width controller 11 of the transmitter 10 selects one of four kinds of widths of pulses to be output according to the states of the incoming signals S0 and S1.

In the state where the pulse width of the input signal is selected through the pulse width controller 11 as described above, the pulse generator 12 receives the reference clock (referred to as RCLK below the reference clock) and is synchronized with the reference clock RCLK. 2, (a) to (d), one of four pulses having different pulse widths is applied to the transmission path 20.

The pulse rising edge detector 31 of the receiving unit 30 detects the rising edge of the signal entering through the transmission path 20 and generates a reference clock RCLK 1 to be used in the receiving unit 30.

In the N-pulse generator 32, the receiving unit reference clock RCLK 1 produced by the pulse rising edge detector 31 as described above is used for the pulse width control delay amount used in the pulse width controller 11 of the transmitting unit 10; Four decoding pulses D0-D3, delayed by the same amount, are made as shown in Figs.

The pulse decoder 33 compares the four decoding pulses D0-D3 and the signals input through the transmission path 20 to restore the original signal.

For example, as shown in (a) of FIG. 2, in the case of S01_0, a high pulse is detected by a logical product operation of the signal received through the transmission path 20 and D0 as shown in (e) of FIG. .

As shown in FIG. 2B, in the case of S01_1, the logical product operation of the signal received through the transmission path 20 and D1 as shown in FIG. 2E and D1 as shown in FIG. The high pulse is detected by this.

As shown in FIG. 2B, in the case of S01_0, D0 as shown in FIG. 2E, D1 as shown in FIG. 2B, D2 as shown in FIG. The high pulse is detected by the AND operation of the signal received through.

As shown in FIG. 2B, in the case of S01_0, D0 as shown in FIG. 2E, D1 as shown in FIG. 2B, D2 as shown in FIG. A high pulse is detected by a logical product operation of the signal received through D3 and the transmission path 20 such as).

At this time, one of the data outputs, which are the original signal values, is made high by using the detected high pulse.

As described in detail above, the present invention reduces the number of transmission paths and reduces the number of transmission paths required for signal transmission by applying and transmitting n states having different widths to one transmission path. The design area is reduced, and only a small number of transmission paths may be driven, thereby reducing current consumption due to signal transmission.

Preferred embodiments of the present invention are disclosed for purposes of illustration, and those skilled in the art will be able to make various modifications, changes, additions, and the like within the spirit and scope of the present invention, and such modifications and changes should be regarded as belonging to the following claims. something to do.

Claims (4)

In a semiconductor memory device, A transmitter for transmitting a plurality of signals in one transmission path in a pulse state having different widths according to states; And a receiver configured to receive signals of different states transmitted through the transmission path and decode the signals into original signals, thereby performing signal coding using a pulse width. The method of claim 1, The transmitting unit, A pulse width controller for selecting one of n different pulse widths to be output according to a state of a signal to be transmitted; And a pulse generator for applying a pulse width equal to a width selected by the pulse width controller to a transmission path in accordance with a reference clock. The method of claim 1, The receiving unit, A pulse rising edge detector for reading a time point of a received pulse and outputting a receiver internal reference clock; An N-pulse generator for outputting a decoding pulse for delaying the internal reference clock output from the pulse rising edge detector by an amount equal to the delay amount for controlling the pulse width used in the pulse width controller of the transmitter; And And a pulse decoder configured to compare the output of the N-pulse generator with a signal received through a transmission path to separate and output n different states. In the signal coding method of a semiconductor memory device, Selecting one of n types of pulse widths to be output according to the state of a signal to be transmitted; Applying a pulse of a selected width to the transmission line in accordance with the reference clock; Reading the time point of the pulse received through the transmission path and outputting the internal reference clock of the receiver; Outputting a decoding pulse for delaying the internal reference clock of the receiver by an amount equal to the delay amount for controlling the pulse width used by the pulse width controller of the transmitter; And And a process of separating and outputting n different states by comparing a decoding pulse output output in the process and a signal received through a transmission path.