JPH07273555A - Optional waveform generator - Google Patents

Abstract

PURPOSE:To reduce a storage time of data to a waveform data memory by controlling an amplitude of a generated waveform of the optional waveform generator with high accuracy and reducing the used capacity of the waveform data memory when the amplitude is controlled by digital data. CONSTITUTION:Amplitude information Cn is stored in a packet memory 3, digital data being normalized with amplitude of an output waveform are stored in a waveform data memory 4, a digital multiplier 16 provided between the waveform data memory 4 and a D/A converter 7 multiplies an output 15 of the amplitude information Cn by a waveform data output and provides an output of the product. Furthermore, the amplitude is controlled by selecting with changeover the waveform data output or the amplitude information Cn output based on control data stored in the packet memory 3 for each waveform packet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when an arbitrary waveform is generated by a mixed IC tester or the like, controls the amplitude with high accuracy, reduces the amount of use of the waveform data memory, and stores the data in the memory. The present invention relates to an arbitrary waveform generator with reduced storage time.

[0002]

2. Description of the Related Art When testing a semiconductor device, which is an object to be tested, using a semiconductor testing apparatus such as a mixed IC tester, it is necessary to add various waveform outputs by an arbitrary waveform generator. FIG. 2 is a block diagram showing a configuration concept of a conventional arbitrary waveform generator. First, there is a clock 8 for controlling the address controller 1, the waveform data memory 4, and the D / A converter 7. When it is necessary to output various output waveforms 9, which are output waveforms, when the packet switching signal is input, the start address 13 and the stop address 14 are output from the packets 1 to n of the packet memory 3. Next, those outputs are controlled by the address controller 1 and input to the waveform data memory 4. Here, the predetermined waveform data is calculated and generated in advance and stored in the waveform memory data 4. Then, it is output as D / A converter input data 5, and D / A
It is input to the converter 7 and output from the D / A converter 7 as a waveform output 6 to provide various output waveforms 9.

That is, when the arbitrary waveform generator of the prior art generates a waveform that needs to be generated, a method of individually calculating each time and storing it has been adopted.
That is, even when only the amplitude of the output waveform is changed as shown in various output waveforms 9, the waveform data of each amplitude is calculated and generated and stored in the waveform data memory 4, and the waveform data is stored. It was realized by switching the address of the memory 4. Therefore, even if waveforms with different amplitudes are output, the method of calculating and storing in the memory requires a long time for calculation and storage, and the memory capacity becomes large. Had.

[0004]

In the prior art method of controlling the amplitude of the generated waveform of the arbitrary waveform generator, the waveform data of each amplitude is calculated and stored in the packet memory, and the packet switching is performed. The amplitude was controlled by switching the address of the waveform data memory by the signal. Therefore, even if you want to output waveforms that have the same waveform but different amplitudes, the waveforms of each required amplitude are calculated and stored in memory. No, but it also took a lot of time to store.

Incidentally, in the past, when the analog waveform was directly controlled by the D / A converter output, the ATT, that is, the attenuator and the VGA, that is, the voltage control amplifier were used in some cases. It was not possible to control the amplitude with high precision due to the badness of. Therefore, in the amplitude control of the generated waveform of the arbitrary waveform generator by the digital data in the present invention, the D / A converter input data is controlled by the digital data of the generated waveform amplitude which is desired to be changed, that is, the high precision The purpose is to realize a device in which the amplitude can be controlled, the amount of memory used for each waveform is reduced, the waveform data memory is effectively used, and the storage time is significantly reduced.

[0006]

In order to achieve the above object, according to the present invention, a start / stop address for determining a waveform is stored in the packet memory 3 and amplitude data for controlling the amplitude is stored. The amplitude of the generated waveform was controlled by additionally storing 15 and providing a digital multiplier for multiplying the waveform data and the amplitude data.

[0007]

[Action]

(1) According to the present invention, unlike the prior art, as shown in the memory contents of FIG. 1, packets 1 to 3 are both start address A1 and stop address B1, and the same waveform data is used. . At that time, the amplitude information is C1,
Different from C2 and C3. Then, in packet 4, the start address and stop address are A for the first time.
2 and B2, and amplitude information changed to C4 are stored. In other words, when you want to change only the amplitude,
That is, when you want to control the amplitude,
It indicates that the data that determines the waveform can be shared.

When the waveform data to be output has a long waveform data length, that is, when the number of data points is large, or when it is desired to change the amplitude in multiple steps, for example, how the IC of the object to be measured may differ due to the difference in amplitude. It may be necessary to test for behavior. In the present invention, the required waveform output data is generated by combining and multiplying the short waveform data of only the waveform from the waveform data memory by the digital multiplier and the simple amplitude information from the packet memory. For this reason, the capability of the waveform data memory can be effectively used.

[0009]

1 is a block diagram showing the concept of an arbitrary waveform generator according to an embodiment of the present invention. (1) Unlike the prior art, the packet memory 3 is provided with amplitude information C1 ... Cn. Further, as shown in FIG. 1, only the waveform data memory 4 having different waveforms is stored. That is, one sine wave,
It also means that you have one square wave. Therefore, information containing information that changes the amplitude is not stored. (2) In the present invention, the digital multiplier 16 for changing the amplitude to the required value is provided between the waveform data memory 4 and the D / A converter 7.

(3) A command is issued to the packet memory 3 by the packet switching signal 2, and the required waveform data is converted into the waveform data memory under the control of the address controller 1 using the start address An and the stop address Bn of the corresponding packet. It is output from 4 and input to the digital multiplier 16. At the same time, the amplitude information in the packet memory 3
Cn is also input to the digital multiplier 16 to change the amplitude of the waveform data. (4) Then, the D / A converter input data 5 output from the digital multiplier 16 is controlled by the clock signal 8 and output from the D / A converter 7 as the waveform output 6.

(5) If a digital adder is used in place of the digital multiplier 16 of the embodiment of the present invention, a waveform output that changes the offset instead of changing the amplitude can be obtained. (6) Further, if a digital adder is further added to the digital multiplier 16 having the configuration of the embodiment of the present invention to switch both units, waveform output of both amplitude change and offset change is possible. . (7) Further, if a direct digital synthesizer (DDS) using a phase accumulator is used instead of the waveform data memory 4 of the configuration of the embodiment of the present invention, the waveform amplitude of DDS can be controlled with high accuracy.

Since the present invention is constructed as described above, it has the following effects. (1) In the prior art, even if the arbitrary waveform generator generates and outputs waveforms that differ only in amplitude, the method is to calculate and input each for different amplitudes, and then store it in the waveform data memory. The storage time becomes long, and the waveform data becomes large, resulting in a large capacity of the waveform data memory. According to the present invention, the calculation / storing time is remarkably short, the amount of waveform data is small, and the waveform data memory can be effectively used.

(2) Further, since it can be configured by a digital multiplier or a digital adder instead of using an ATT or VGA, it is possible to control the amplitude of the waveform with extremely high precision and output the arbitrary waveform. The generator was realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration concept of an arbitrary waveform generator according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration concept of a conventional arbitrary waveform generator.

[Explanation of symbols]

 1 address controller 2 packet switching signal 3 packet memory 4 waveform data memory 5 D / A converter input data 6 waveform output 7 D / A converter 8 clock 9 various output waveforms 10 output 11 output 12 output 13 start address output 14 stop address output 15 Amplitude information output 16 Digital multiplier

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[Procedure amendment]

[Submission date] July 8, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

Title: Arbitrary waveform generator

Claims (4)

[Claims] 1. A packet memory (3) storing amplitude information for controlling amplitude, a waveform data memory (4) storing digital data in which the amplitude of a generated waveform is normalized, and the waveform data memory (3). A digital multiplier (1 that inputs and multiplies the output of 4) and the output of the amplitude information (15)
An arbitrary waveform generator characterized in that 6) is provided, a D / A converter (7) that receives the output of the digital multiplier (16) is provided, and the above configuration is provided. 2. The arbitrary waveform generator according to claim 1, wherein a digital adder is used instead of the digital multiplier (16). 3. The arbitrary waveform generator according to claim 1, wherein a digital adder is provided in addition to the digital multiplier (16), and each output is switched and connected to the D / A converter (7). vessel. 4. The arbitrary waveform generator according to claim 1, wherein a phase accumulator is used instead of the waveform data memory (4).