CN1256831C - Programmable high-frequency pulse signal generator - Google Patents

Abstract

A programmable high-frequency pulse signal generator is constructed as follows: a computer is connected to a DSK board via a parallel port on the DSK board, data input terminals of a main signal D/A conversion chip and a reference signal D/A conversion chip are connected to a sub-board slot on the DSK board, an input terminal of a main power amplifier is connected to an output of the main signal D/A conversion chip, and an output is connected to a main output terminal; an input terminal of a reference power amplifier is connected to an output of a reference signal D/A conversion chip, and an output is connected to a reference output terminal. The invention has the characteristics of simple structure, easy upgrade and expansion of functions, ability to generate high-frequency signals, periodic signals, arbitrary waveform signals, and ability to provide multi-channel synchronous output.

Description

Programmable high frequency pulse signal generator

Technical field:

The invention relates to a signal generator, in particular to a programmable high-frequency pulse signal generator.

Background technique:

Signal generators are widely used in various experimental instruments and systems that require signal input. Specifically, different output signals have their own unique applications and cannot be substituted. For example, a signal generator with a strictly synchronous reference signal output is necessary in a small spot measurement system ("Methods for Measuring Small Spots in Large Numerical Aperture Optical Systems", Xu Wendong, Qian Fuxi, China Laser, 2003, No. 30 Volume, No. 2, pp. 171-174), the main output signal is connected to an acousto-optic modulator as a modulating signal, and its output amplitude can be adjusted, and its strictly synchronous reference signal is connected to a lock-in amplifier for demodulation, and the output amplitude of the reference signal is not It should change with the change of the main output signal amplitude; the function signal generator that can output square wave, pulse train, sawtooth wave, sine wave and other signals is used to apply the ideal waveform to the designed circuit to verify its performance; arbitrary waveform signal generation The device can be used for over-pulse, peak, damping transient, frequency mutation and other factors to detect the possible devastating consequences of the circuit, which is especially suitable for circuits used in aerospace, military, railway and some important fields with complex important.

In the prior art programmable arbitrary digital signal generator (utility model patent, application number: 93207151.1), as shown in Figure 1: the device takes 8031 single-chip microcomputer as the core, including keyboard and display 01, clock circuit 03, external trigger input circuit 04 , waveform data memory 05, waveform length controller 06, frequency synthesizer 07, address generator 08, and D/A converter 09. When working, the 8031 MCU calculates arbitrary waveform data and writes it to the waveform data memory 5 in Figure 1, then reads out or directly reads out the periodic waveform data from the waveform data memory, and finally outputs the programmable signal through the D/A conversion circuit. Although it has the advantages of high output frequency resolution, good frequency setting repeatability and program control of frequency, there are still some shortcomings:

1) The structure is complex, the integration of peripheral circuits is not high, and it is difficult to upgrade and expand;

2) The data addressing range of the 8031 single-chip microcomputer is limited, and the table capacity is not high; the number of data bus bits is low, and the output signal precision is low; Great difficulty with high-frequency signals;

3) There is no synchronous output terminal that can provide the same waveform or different waveform reference signals that are strictly synchronized or have a certain fixed delay time;

4) There is no power amplification and low-impedance output circuit behind the D/A conversion circuit, so it is not convenient to directly connect to the load.

Invention content:

The problem to be solved by the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a programmable high-frequency pulse signal generator. It should have a simple structure, easy to upgrade and expand functions, and can generate high-frequency signals, periodic signals, and arbitrary waveform signals. , can provide the characteristics of multiple synchronous output.

Basic thought of the present invention is:

1) Use the DSP starter kit DSK board, high-speed D/A converter and low output impedance power amplifier circuit to form a signal generator. The DSK board integrates all peripheral circuits or functions in the prior art except D/A converter and 8031 single-chip microcomputer, and has a sub-board expansion slot. We design the high-speed D/A converter and the low output impedance power amplifier circuit into a sub-board, which is connected to the expansion slot of the sub-board. The structure is simple, and the extension function only needs to replace the sub-board or expand the sub-board.

2) The DSP digital signal processing chip on the DSK board replaces the 8031 single-chip microcomputer in the prior art, compared with it, the data addressing range of the DSP digital signal processing chip is large; 16-bit or 32-bit data width, the output signal precision is high; the instruction Short cycle; data and instructions are stored separately, pipeline operation, with dedicated hardware multiplier and special instruction set, high instruction efficiency, can generate 16-bit or 32-bit digital signals with short time intervals, and generate high-frequency and high-precision signals It has great advantages and is more suitable for realizing programmable high-frequency pulse signal generator.

3) The two-way high-speed D/A converter on the sub-board converts 16-bit or 32-bit discrete digital signals, and uses the write signal of the DSP chip to control the high-speed D/A converter to achieve synchronization or delay between multiple signals;

4) The low output impedance power amplifier circuit realizes signal power amplification and low-impedance output, which is convenient for loading.

Technical solution of the present invention is as follows:

A programmable high-frequency pulse signal generator, the composition of the generator is: the computer is connected to the DSK board through the parallel port on the DSK board, and the data input terminals of the main signal D/A conversion chip and the reference signal D/A conversion chip are connected to the DSK board. The sub-board slot on the DSK board is connected, the input end of the main power amplifier is connected with the output of the main signal D/A conversion chip, and the output is connected with the main output end; the input of the reference power amplifier is connected with the output of the reference signal D/A conversion chip, and the output is connected with the output of the reference signal D/A conversion chip. Reference output connection.

The main signal D/A conversion chip, main power amplifier, main output terminal and reference signal D/A conversion chip, reference power amplifier and reference output terminal are integrated together to form a sub-board, which is connected with the sub-board slot on the DSK board.

Compared with the prior art, the advantages of the present invention:

(1) The DSK board is used as the generation part of the discrete digital signal, and there is no need to design the peripheral interface circuit for the DSP chip. The DSK board already includes the DSP chip, external random access memory (SRAM), flash memory (FLASH), simulation interface, and host The parallel port of computer communication and the sub-board interface can be conveniently debugged, the upper computer control can also run independently and the sub-board expansion (D/A converter and power amplifier circuit can be made into a sub-board and inserted in the sub-board slot, due to the batch size of the DSK board Production, its price is very low, helps to reduce the cost of device of the present invention.

(2) Since the internal program can run independently after being debugged and set by the emulation interface, it can also communicate with the computer in real time, and the programmable high-frequency pulse signal generator of the present invention can produce a single pulse whose output amplitude and pulse width can be controlled by the computer, Continuous pulse whose output amplitude, pulse width and delay time can be controlled by computer, other waveforms generated by digital signal processor (DSP) and arbitrary waveforms stored by upper computer, and the same waveform which is strictly synchronized or has a certain fixed delay time can be provided at the same time Or the reference signal of different waveforms, the amplitude, delay time and waveform of the reference signal are also fully controlled by the computer.

(3) The high-speed D/A converter and the low output impedance power amplifier circuit can be made together as a sub-board inserted into the sub-board slot on the DSK board, which is easy to assemble and is also conducive to future maintenance, upgrades and updates. In short, compared with pure high-frequency signal generators, it is cheap and powerful.

Description of drawings:

Fig. 1: It is a schematic diagram of the principle of a programmable arbitrary digital signal generator in the prior art.

Fig. 2: is the schematic diagram of the principle of the present invention based on the DSP digital signal processor.

Fig. 3: is a structural diagram of a D/A conversion device in an embodiment of the present invention.

Figure 4: Several forms of output signals in the embodiment of the present invention.

Detailed ways:

The block diagram of the embodiment of the programmable high-frequency pulse signal generator of the present invention is as shown in Figure 2, as can be seen from the figure, the composition of the programmable high-frequency pulse signal generator of the present invention is: the computer 11 communicates with the DSK through the parallel port 1201 on the DSK board 12 The board 12 is connected, the data input end of the main signal D/A conversion chip 13 and the reference signal D/A conversion chip 18 are connected with the sub-board slot 1202 on the DSK board 12, and the input end of the main power amplifier 14 is converted with the main signal D/A The output of the chip 13 is connected, and the output is connected to the main output terminal 15 ; the input of the reference power amplifier 17 is connected to the output of the reference signal D/A conversion chip 18 , and the output is connected to the reference output terminal 16 .

The DSK development board 2 of the discrete digital signal generation part of this embodiment adopts the TMS320VC5402 DSK development board of TI Company. This DSK development board has a digital signal processor DSP chip with an output 16-bit instruction cycle of 10ns, an external SRAM of 64K, and a 56K The FLASH memory, the JTAG test bus controller, the interface of the expansion daughter board, that is, the daughter board slot 1202 and the parallel port 1201 connected to the host computer and other equipment. The DSP digital signal processor on the DSK board can have many different guiding modes to adapt to different occasions where the DSK is used. For example, use the JTAG debugger to realize the default mode of emulation; the HPI (Host Port Interface) mode when the host software or driver will load the memory through the parallel port; use 8, 16, 32-bit ROM or FLASH memory to guide the DSK In this mode, the DSK development board can run independently without connecting to the host computer. In the actual design, the latter two boot modes are generally used. In the third mode, the program is burned into the FLASH, which can not only make the DSK development board run independently, but also ensure that the program is difficult to be borrowed by others. The present invention is an extended application. In the embodiment Use the second boot mode. The two-way D/A conversion chip in the digital-to-analog conversion part—the main signal D/A conversion chip 13 and the reference signal D/A conversion chip 18 adopt AD9732, which is a ten-bit high-speed digital-to-analog conversion chip with a conversion time of 5ns. There is a data latch. The rising edge of the latch signal Clock triggers the latch of the data, which is sent to the D/A conversion network to generate an analog signal output. The chip structure is shown in Figure 3.

The structure of the signal generator is shown in Figure 2. The computer 11 and the DSK development board 12 communicate through the parallel port 1201. The program that generates arbitrary waveforms is processed by the DSP chip and then outputs discrete digital signals. The 16-bit output lines are separated, and the high ten bits are given to the main signal D /A conversion chip 13, the lower 6 bits are for the reference signal D/A conversion chip 18. Note that when the 6-bit data line is connected to the 10-bit D/A converter, the lower 8 bits of the D/A converter are divided into four strands, and the upper two bits are added to a total of 6 strands to connect to the 6-bit input data or the 6-bit data line is directly connected to the 10-bit D/A converter. The upper 6 bits of the 10-bit D/A converter. The data latches of the two D/A conversion chips are assigned the same address, and the write signal W of the DSP chip is supplied to the Clock pins of the two D/A conversion chips after passing through the NOT gate. When the DSP outputs a discrete digital signal, the Clock pin has a rising edge signal, and the rising edge locks the digital signal in the data latch of each D/A chip at the same time, and then converts and outputs a synchronous analog signal. The signal generator is composed of a DSP5402 data processor with an instruction cycle of 10ns and a high-speed D/A conversion chip with an instruction cycle of 5ns, which can output 30ns single pulse, high-frequency continuous pulse and square wave. Or use the 32-bit floating-point DSP development board DSK with a shorter instruction cycle, and output 32-bit data to satisfy two 10-bit AD9732 chips, so that the accuracy of each D/A converter can be guaranteed compared with the previous example.

The D/A converter is followed by a power amplifier—the main power amplifier 14 and the reference power amplifier 17, which realize power amplification and impedance conversion functions, and change the high input impedance into a low output impedance of 50 ohms or 75 ohms, which is convenient for loading.

Fig. 4 is a signal generated by the programmable high-frequency pulse signal generator of the present invention in the static and dynamic test system of the optical disc material medium. as the picture shows:

Static a is the state signal of writing and erasing. The signal generator sends out a single pulse with adjustable amplitude and pulse width to the acousto-optic modulator. The laser makes dots on the test material through the acousto-optic modulator to complete the writing and erasing operations.

The static b1 is also output by the signal generator to the acousto-optic debugger to debug the laser, and b2 is the synchronization signal of b1, which is finally input to the demodulator, and b2 is used as the reference signal for b1 demodulation. Dynamic a1 has the same function as static b1, but dynamic a2 and b2 are the signals provided by the signal generator to the scanning component, which is not available in the static test. Dynamic b1 is the signal provided by the signal generator to the AOM for read operation. Because these signals are periodic signals, the waveform data is written in the FLASH on the DSK board, and the computer can directly input the waveform and parameters of the required output signal to control the DSP chip to read these waveform data.

Claims (2)

1, a kind of programmable high-frequency pulse signal generator, the formation that it is characterized in that this generator is: computer (11) links to each other with DSK plate (12) by the parallel port (1201) on the DSK plate (12), the data input pin of main signal D/A conversion chip (13) and reference signal D/A conversion chip (18) is gone up daughter board groove (1202) with DSK plate (12) and is linked to each other, the input of main power amplifier (14) is connected with main signal D/A conversion chip (13) output, and output is connected with main output (15); The output of the input of reference power amplifier (17) and reference signal D/A conversion chip (18) is connected, exports and is connected with reference to output (16).

2, programmable high-frequency pulse signal generator according to claim 1, it is characterized in that described main signal D/A conversion chip (13), main power amplifier (14), main output (15) and reference signal D/A conversion chip (18), reference power amplifier (17) and integrate the formation daughter board, go up daughter board groove (1202) with DSK plate (12) and link to each other with reference to output (16).

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