SU1092483A1 - Function generator - Google Patents

Abstract

1. A FUNCTIONAL GENERATOR containing a clock pulse generator, an address counter connected by outputs to the memory inputs of sine values, and a digital-to-analog converter connected by output to an input of a low-pass filter whose output is a function generator output, characterized in that class of reproduced functions, the element I, the counter of the argument, the frequency memory, the code-frequency converter, the amplitude memory,, are additionally introduced into it. the function selection block of the generated function and the multiplication unit connected by outputs to the inputs of a digital-to-analog converter, the first group of inputs to the memory outputs of sine values, and the second group of inputs to the outputs of an amplitude memory module connected by the first group of address inputs to the first group of outputs of the selector characteristics of the generated function and with the first GR5SHPOY address inputs of the frequency memory block, and the second group of address inputs with the outputs of the argument counter and with the second group of address inputs Odes of a frequency memory unit connected by outputs through a code-frequency converter to the counting input of an address counter connected by an installation-. Named inputs with the second group of outputs of the block for selecting the characteristics of the generated function connected by the first input to the start bus of the function generator, the second input to the overflow output of the argument counter, the first output to the control inputs of the installation of the counter code of the argument and the ad.res counter, the second input to the first input of the element i И, and the third group of outputs to the mustache (the setting inputs of the argument counter connected by the counting input to the output of the element I connected by the BTOPbiM input to the output of the clock generator imp 2. The generator according to claim 1, of which is the one and the same so that the block for selecting the characteristics of the generated function contains registers, program switches, pulse shaper and a trigger connected by a setting input and zeroing input to the first and the second inputs of the block for selecting the characteristics of the generated function, respectively, and the output to the second output of the block for selecting the characteristics of the generated function and to the input of the pulse former connected with the output to the first output of the block for selecting the characteristics of the generated function and the equal inputs of four registers, each of which is connected by information inputs to the executors of the corresponding software

Description

a switch, wherein the outputs of the first and second registers are the first group of outputs of the block for selecting the characteristics of the generated function, and

the outputs of the third and fourth registers are the second and third groups of outputs of the block for selecting the characteristics of the generated function. respectively.

The invention relates to automation and computing and can be used to generate signals of complex shape, in particular oscillating functions. I. A known function generator includes a pulse generator, a code-frequency converter, a control unit, an OR element, a period generator, a distributor, a memory block, a register, a switch, and digital-analog converters 1. The disadvantage of this generator is a limited class of reproducible functions. A functional generator is also known, which contains an impulse generator, a frequency divider, counters, switches, adders, memory devices, switch blocks, multipliers, a pulse shaper trigger, a key, a comparison unit, a quad, a digital-to-analog converter, and a low-pass filter l2j. The disadvantages of this generator are the complexity of the technical implementation and reduced speed. The closest to the present invention is a functional generator containing a clock pulse generator, an address counter connected by outputs to the memory inputs of sine values, and a digital-to-analog converter connected by an output to an input of a low-pass filter, the output of which is the output of the clock generator is connected to the counting input of the address counter, and the outputs of the storage device are connected to the inputs of the digital-to-analog converter of the Sz. The disadvantage of such a generator is the limited class of reproducibility of functions due to the limited size of the storage device, which does not allow reproducing, in particular, oscillating functions. The purpose of the invention is to expand the class of reproducible functions. The goal is achieved in that a functional generator containing a clock pulse generator, a counter connected to the memory inputs of the sine values, and a digital-to-analog converter S connected by an output to the input of a low-pass filter whose output is the output of a functional generator, is additionally introduced with an And, argument counter, frequency memory block, code-frequency converter, amplitude memory block, characteristic function selection block and multiplication unit, plug The outputs to the inputs of the D / A converter, the first group of inputs to the memory outputs of the sine values, and the second group of inputs to the outputs of the amplitude memory module connected by the first group of address inputs to the first group of outputs of the function selection block of the generated function and the first group of address inputs of the block frequency memory, and the second group of address inputs - with the outputs of the argument counter and the second group of address inputs of the frequency memory unit connected by the outputs through the code-converter converter Tota to the counting input of the address counter, connected by the setup inputs to the second group of outputs of the block for selecting the characteristics of the generated function, connected by the first input to the function generator start bus, the second input to the overflow output of the argument counter, the first output to the control inputs of setting the argument counter code and the address counter , the second input is to the first input of the AND element, and the third group of outputs is to the installation inputs of the argument counter connected by the counting input with the output of the AND element, chennogo second input to the output of the clock. The block for selecting the characteristics of the generated function contains registers, program switches, pulse generator and trigger connected by a setup input and zeroing input to the first and second inputs of the characteristic function selection block of the generated function, respectively, and the output to the second output of the characteristic selection block of the generated function and the pulse generator input connected by the output to the first output of the block for selecting the characteristics of the generating and non-generating function and to the control inputs of four registers, each of which connecting a data inputs to the outputs of the corresponding software switch, the outputs of the first and second registers are the first band characteristics selecting unit outputs the generated functions, and the outputs of the third and fourth registers - the second and third groups of outputs respectively generated by the function selection unit characteristics. FIG. 1 shows a block diagram of a function generator; FIG. 2 is a functional block diagram of the selection of characteristics of the generated function; in fig. 3 - examples explaining the operation of the functional generator; The functional generator contains 1 clock pulse generator, element 2, argument 3 counter, block 4 for selecting the characteristics of the generated function, frequency memory block 5, amplitude 6pam block, converter 7c frequency, an address counter 8, a memory device 9 sine values, a multiplication unit 10, a digital converter tax converter 11 and a low-pass filter 12, a launch bus 13. Block 4 contains a trigger 14, a pulse generator 15, four program switches 1b (, 16p, I6j, 164 and four registers i /, i / 2. The first group of outputs of block 4 is formed by the outputs 18 of the register 17 and the outputs 19 of the register 17, the second group The outputs of block 4 form the outputs 20 of register 17, the third group of outputs of block 4 are formed by outputs 21 of register 17, the second output of block 4 is indicated by 22, the first output is 23. The operation of the function generator is based on the representation of oscillating special functions in the form of sinusoidal voltage continuously changing the amplitude and frequency A (t + t) (to + t) + ia, where tp is the initial moment of time; fg is the initial phase of the oscillation. The introduction of the initial moment of time is due to the fact that some special functions have values at the origin of the coordinates equal to infinity and they need to be generated starting with a certain argument value. The amplitude and frequency functions A (t) and c) (t) are recorded as a sequence of digital codes in the frequency memory 5 and the amplitude memory 6. The selection of these sequences is made simultaneously by the counter 3 argument code, in which the bit outputs are connected to the second group of address inputs of blocks 5 and 6. The first group of address inputs of these blocks is specified from block 4 and indicates the type of special function and its number. Functional generator operates as follows. The starting pulse at the input 24 triggers the trigger 14 (Fig. 2). From the direct output of the trigger 14, the potential of the logical 1 at the output 22 of the block 4 arrives at the first input of the element 2 and opens it. Clock pulses from the generator 2 clock pulses through the element And 2 arrive at the counting input of the counter 3 argument. The same potential of logical 1 from the trigger 14 goes to the driver. 15 pulses, which on the leading edge produces a short pulse. Inside block 4, this impulse arrives at the control inputs of registers 17 4 registers, codes are recorded from software switches 16 to 16. Software switch code 16 indicates the type of special function, for example, 0001 for Bessel functions, 0110 for Laguerre polynomials, and so on. The software switch code 16 indicates the function number, for example, 0000 — the Bessel function Jo (t), 0111 — the Bessel function Jy. (T), etc. The code of the program switch 16} denotes the initial phase of the oscillation Y, the code of the program switch 16 denotes the value of the argument from which the formation of the special function begins. A short pulse from the imaging unit 15 to the output 23 of unit 4 is fed to the control inputs of the installation of the counter code 3 argument and the counter 8 address. Counter 3 arguments for this impulse enter the code of the initial value of the argument from the output group 21 of block 4, the code for the initial phase of the oscillation from output group 20 of the block 4 is entered into the counter, thus the generation of a special function begins with some initial values of the argument and initial phase. The pulses of the oscillator 1 clock pulse received at the input of the counter 3 argzt 1ta through the element 2, change the number at the outputs of the bits of the counter 3. This changes the address on the second groups of address inputs of memory devices 5 and 6 The codes of the amplitude and frequency function values for the selected type and function number specified by the first groups of address inputs of devices 5 and 6 from block 4. The code of the frequency function is delivered to the code-frequency converter 7, from the output of which the variable frequency pulses of the input are fed to the counting input of the counter 8. The number at the outputs of the bits of the counter 8 varies faster or slower depending on the code of the frequency function. In the memory device of 9 sine values, the sine values of the numbers supplied to the address inputs are stored. These sines in the form of digital codes go to the first group of inputs of the multiplication unit 10, and to the second group of inputs; This block receives the amplitude function code from memory 6. The digital product code from the outputs of multiplication unit 10 is fed to the digital-to-analog converter 1 83 where it is converted to analog voltage, the low-pass filter 12 smoothes the step variations of this voltage. FIG. Figure 3 shows amplitude and frequency functions for the 11th function of the parabolic cylinder Y, (t) and for the 2nd Bessel function J (t) as examples. The values of the amplitude and frequency functions for each specific case are determined directly from the graphs and tables of special functions, since it is difficult to determine them analytically. For example, the amplitude function can be approximately constructed from the maxima of the oscillating function, and the frequency function from the intervals between the zeros. The resulting discrete values in the graph are connected by a smooth line, and then approximated by a step function (Fig. 3). Stepwise varying amplitude and frequency function values for different: special functions are recorded in blocks 5 and 6 of memory. In this form, the functional generator is ready for operation. Software switches 16 /, - 164 specify the type and number of the function, the initial phase (for example, in Fig. 3, with t 0, the initial phase is 180, and in Fig. 3B O) and, if necessary, the initial value of the argument (such a necessity arises In those cases, if the initial value of the special function is infinity at the point t О When the hardware is implemented, the functional generator is simple: the counters 3 and 8 will require 2 K155IE7 chips, the characteristic selection blocks 4 K155IR13 chips and one K155ТМ2, ROM 5,6, 9 1-2 chips K556PT5, code converter- the pulse frequency is 2 chips K155IE8 and 2 K155IE5, the multiplication unit will require 8 chips, a digital analog converter 1t and a low-pass filter 12 on 1 chip. Together with the rest of the nodes it is 27-30 chips (all calculations are for an 8-bit generator implementation).

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Claims (2)

1. A FUNCTIONAL GENERATOR comprising a clock generator, an address counter connected by outputs to the inputs of a sine value storage device, and a digital-to-analog converter connected by an output to an input of a low-pass filter, the output of which is an output of a functional generator, characterized in that, in order to expand the class reproducible functions, an element And, an argument counter, a frequency memory unit, a code-frequency converter, an amplitude memory unit, are additionally introduced into it. a unit for selecting the characteristics of the generated function and a multiplication unit connected by outputs to the inputs of the digital-to-analog converter, the first group of inputs to the outputs of the sine value memory device, and the second group of inputs to the outputs of the amplitude memory unit connected by the first group of address inputs to the first group of outputs of the characteristic selection unit the generated function and with the first group of address inputs of the frequency memory block, and the second group of address inputs - with the outputs of the argument counter and with the second group of address inputs b frequency memory lock connected by outputs through a code-frequency converter to the counting input of an address counter connected by setting. inputs with the second group of outputs of the block for selecting the characteristics of the generated function, connected by the first input to the start bus of the functional generator, the second input to the output of the overflow of the argument counter, the first output to the inputs of the control setting the counter code of the argument and address counter, the second input to the first input element And, and the third group of outputs - to the installation inputs of the argument counter, connected by the counting input to the output of the element And, connected by the second input to the output of the clock generator. 2. The generator according to claim 1, characterized in that the block for selecting the characteristics of the generated function contains registers, program switches, a pulse shaper and a trigger connected by the setup input and zeroing input to the first and second inputs of the block for selecting the characteristics of the generated function, respectively, and the output to the second output of the block for selecting the characteristics of the generated function and to the input of the pulse shaper connected by the output to the first output of the block for selecting the characteristics of the generated function and with control inputs three registers, each of which is connected by information inputs to outputs ‘of the corresponding software SU „„ 1092483 switches, and the outputs of the first and second registers are the first group of outputs of the block for selecting the characteristics of the generated function, and the outputs of the third and fourth registers are the second and third groups of outputs of the block for choosing the characteristics of the generated function, respectively