JPH02265313A - Semiconductor circuit - Google Patents

Abstract

PURPOSE:To output directly a change in an input signal to minimize the time delay of a generated pulse by providing a function utilizing directly an input pin signal as a control signal not passing through a logic circuit to supply the control signal with faster response. CONSTITUTION:A signal from a delay circuit 3 and an input signal 1 are inputted to an exclusive OR circuit 7, from which the change in the input signal 1 is outputted directly as an output signal 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a circuit for supplying a control signal synchronized with an input signal in a semiconductor circuit.

[Conventional technology]

FIG. 4 is a circuit diagram showing a conventional ATD signal generation circuit. In the figure, (1) is an input signal, (2) is an internal transmission signal, (3) is a delay circuit for controlling the pulse width of ATD, and (4)
is the pulse generation circuit, (5) is the waveform shaping driver (6)
indicates the output signal of the waveform shaping driver (5). FIG. 5 is a timing chart showing waveforms of various parts in the circuit of FIG. 4.

Next, the operation will be explained. After the input signal (1) passes through an address buffer, it is input to a delay circuit (3) and a pulse generation circuit (4). The output of the delay circuit (3) is input to two transmission gates, each of which performs an ON or OFF operation. At this time, an inverted signal is input to each input of the transmission gate, and the delay circuit (3)
It is possible to generate a pulse that becomes the lLm signal by the width of the time delayed by .

[Problem to be solved by the invention]

As can be seen from the waveforms at points E and F shown in FIG. 5, the width of the received pulse is determined by the change in point A in FIG. 4 and the change time of the output of the delay circuit (3).

In recent years, as speeds have increased, access times have become faster.
Correspondingly, the time required for the ATD signal to complete is becoming shorter, and if the signal start time is delayed, the pulse width becomes narrower, making it impossible to operate satisfactorily. For example, to make a 1-ounce product with high-speed SRAM, the ATD signal is considered to be equalized at 5 nS. Then, the pulse width needs to be approximately 3 nS assuming a delay from the input of 2 nS.

A pulse width of 3 nS is not sufficient even considering internal capacitance.

This invention was made to solve problems such as 1 fertilizer.
The purpose of this is to bring the pulse generation start point as close to the change in the input signal as possible to supply stable pulses.

[Means to solve the problem]

The semiconductor circuit according to the present invention uses the input signal directly and brings the start point of the output signal closer to the start point of the input signal, thereby ensuring a sufficient pulse width.

[Effect]

The semiconductor circuit according to the present invention can generate a pulse almost simultaneously with a change in an input signal, and has an excellent effect of high-speed response.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram showing an ATD signal generating circuit. In the figure, (1) to (a) * (5) e (6) are the same as those shown in the conventional example of FIG. 4, so their explanation will be omitted. (7) is an exclusive OR circuit. Figure 2 shows the conventional example shown in Figure 4 for comparison with Figure 1;
FIG. 3 is a timing chart showing the waveforms of each input signal (1) and output signal (6). FIG. 3 is a timing chart obtained by simulation of the waveforms of each part shown in the circuit of FIG.

Next, the operation will be explained. An exclusive OR circuit (
7), a change in the input signal (1) can be directly output as an output signal (6).

The waveforms of each part of the circuit in FIG. 1 are shown in the timing charts of FIGS. 2 and 3.

〔Effect of the invention〕

As described above, according to the present invention, changes in an input signal can be directly output, and the time delay of generated pulses can be minimized.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an ATD signal generation circuit showing an embodiment of the present invention, FIG. 2 is a timing chart showing waveforms of input signals and output signals in the circuits of FIGS. 1 and 4, and FIG. Figure 3 is a timing chart obtained by simulation of the waveforms of each part shown in the circuit in Figure 1, Figure 4 is a circuit diagram of a conventional ATD signal generation circuit, and Figure 5 shows the waveforms at each point shown in Figure 4. This is a timing chart. In the figure, (1) is an input signal, (2) is an internal transmission signal,
(3) C delay circuit, (5) waveform shaping driver, (
6) J, t output signal, (July shows an exclusive OR circuit. In the figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A semiconductor circuit having a function of supplying a control signal with faster response by directly using an input pin signal as a control signal without going through logic in a circuit having a circuit control signal such as an ATD.