SU622070A1 - Digital function generator - Google Patents

Description

one

The invention relates to the field of computing and can be used to generate linear step functions for a piecewise linear approximation of arbitrary nide functions.

The well-known digital function generator 1 contains a time converter into a pulse train, a reversible counter, and blocks of decoding weighting coefficients and memory.

However, such a structure is complex and has a low speed.

And the closest to the invention is a digital function generator 2 comprising a clock pulse generator, a Walsh function generator, a modulo two adder, a delay element, and a first counter, the clock pulse generator output connected to the clock generator of the Walsh function generator, the information inputs of which are connected to the first the group of information inputs of the digital function generator, and the output to the first n through the delay element to the second inputs of the modulo two, the installation inputs and the outputs of the first Meters withstand connected respectively to the second group of information inputs and

the first group of outputs of the digital function generator.

The disadvantage of the generator is the impossibility of generating functions F (x) containing sections with a slope.: | 1, i.e., all the functions it generates are located only in the first and eighth octants. This leads to the need for preliminary normalization of functions at the cost of increased hardware costs.

The aim of the invention is to expand the class of functions generated by the digital generator.

Claims (2)

The goal is achieved by the fact that the digital function generator contains a switch and a second counter, the first and second information inputs of the switch are connected respectively to the output of the clock generator and the output of the modulo two, the control input of the switch to the corresponding information input of the digital function generator, the first and the second outputs of the switch to the counting inputs of the first and second counters, respectively, the outputs of the second counter are connected to the second group of outputs of the digital gene Rattor functions. The drawing shows a diagram of the proposed generator. It contains a clock pulse generator 1, a Walsh function driver 2, a delay element 3, an adder 4 modulo 2, a switch 5, counters 6 and 7, start-pulse input 8 and stop-pulse input 9, the first group of information inputs 10, one of which are used to set the operation mode of the first counter for addition or subtraction at the counting input, and the others for setting the initial state are connected to the counter inputs of the counter, the second group of information inputs 11, the third group of information inputs 12, one of which is for setting the mode ma of the second counter operation for addition or subtraction at the counting input, and others for setting the initial state and connected to the installation inputs of the counter, information input 13 connected to the control input of the switch, and output buses 14 and 15. The increment sign of the sign function ( Af) at the next approximation interval T arrives at one of the inputs 10 of the first group and determines the operation mode of counter 6 (addition or subtraction). Other information inputs of the first group, connected to the corresponding installation inputs of counter 6, are used to enter the initial value of the function F (xo. The increment sign argument (AA :) goes to one of the inputs 12 of the third group, determines the operation mode (addition or subtraction) of the counter 7. Other informational inputs of the third group, connected to the corresponding installation inputs of counter 7, are used to enter the initial value of the argument x. The absolute value of the increment of the function at a given approximation interval is received and the information inputs AND of the second group (the corresponding control inputs of the driver 2) determine the number of the generated Walsh function (, 1, 2, ..., where n is the number of inputs of the second group). From the moment the start-impulse is fed to input 8 before the arrival of the stop pulse to the input 9, the clock pulses of the frequency fo from the output of the generator 1 are fed to the synchronizing input of the former 2. Each switch at the output of the former 2 using the delay element 3 and the modulator 4 modulo two is converted into a pulse of one clock duration ( fo). The number of these pulses in one period of operation of generator 2 is N. If the control input of switch 5 through information input 13 arrives, the pulses from the output of commutator switch 5 arrive at mattress 4 through the input of counter 6 and are added to its content (or subtracted from it) . At the same time, from the output of the generator 1 to the input of the counter 7, the clock pulses are supplied through the switch 5, which will be added to its contents (or subtracted). If the information input is 13 postdud. . J 1 means that the signal drops at a given approximation interval. Function F grows faster than argument x, switch 5 re-switches the counter inputs so that the input of counter 6 is connected to the output of generator 1, and the input of counter 7 to the output of modulo-two. In this case, the mutual replacement of the coordinate axes is carried out: the argument X becomes a function of F and vice versa. The use of the proposed generator provides (taking into account the requirements for the width of the output counters) approximation of the functions of the most arbitrary type. DETAILED DESCRIPTION OF THE INVENTION A digital function generator comprising a clock pulse generator, a Walsh function driver, a modulo two adder, a delay element and a first counter, the clock pulse generator output connected to the clock input generator of the Walsh function, whose information inputs are connected to the first group of information inputs of a digital generator functions, and the output to the first and through the delay element to the second inputs of the modulo two adder, the installation inputs and the outputs of the first counter are connected respectively, to the second group of information inputs and to the first group of outputs of the digital function generator, characterized in that, in order to expand the class of generated functions, it contains a switch and a second counter, with the first and second information inputs of the commentator being connected respectively to the output of the clock generator and the output adder modulo two, the control input of the switch to the corresponding information input of the digital function generator, the first and second outputs of the switch to the counting inputs of the switch second and second counters, respectively, the outputs of the second counter are connected to the second group of outputs of the digital function generator. Sources of information taken into account in the examination 1. USSR author's certificate number 451989, cl. G 06F 1/02, 1974. 2. For the number 2303225/24, cl. G 06F 1/02, 24.12.75, according to which the decision was taken to issue an author's certificate.