CS277613B6 - Connection for microcomputer operation evaluation - Google Patents

Abstract

The circuit for evaluating the operation of a microcomputer operating in the control of small technological objects consists of a clock frequency generator (1), a counter (2), a preselection switch (5), a decoder (3) for evaluating the write and an initialization and signaling circuit (4). The output (11) of the clock frequency generator (1) is connected to the counting input (21) of the counter (2), whose first, second, third and fourth preselection inputs (22, 23, 24, 25) are connected individually to the first, second, third and fourth outputs (51, 52, 53, 54) of the preselection switch (5). The asynchronous recording input (26) of the counter (2) is connected to the output (33) of the decoder (3) of the write evaluation, the first group input (31) of which is connected to the data bus (6) of the microcomputer and the second group input (32) of which is connected to the address bus (7) of the microcomputer. The transmission output (27) of the counter (2) is connected to the input (41) of the initialization and signaling circuit (4), the first output (42) of which is connected to the initialization line (8) of the microcomputer. The second output (43) of the initialization and signaling circuit (4) is connected to the input (91) of the light-emitting diode (9).

Description

The invention relates to a circuit for evaluating the operation of a microcomputer, in particular operating in the control of small technological objects.

To evaluate the correct operation of the microcomputer, specialized units are used to monitor the signals on the bus and evaluate their time sequences and responses. However, in simple microcomputers built mainly using microprocessor technology, such a unit would be more complex than the microcomputer itself and its presence in the system would significantly reduce the reliability of the entire system. However, the presence of said evaluation circuits is necessary, especially in the control of small technological objects by a microcomputer, in order to prevent possible damage to the technological object by a faulty function of the microcomputer.

This problem is solved by a circuit for evaluating the operation of a microcomputer according to the invention, the essence of which consists in that the output of a clock frequency generator is connected to a counter input of a counter whose first, second, third and fourth preset inputs are connected to the corresponding first, second, third and a fourth output of the preset switch and further whose asynchronous recording input is connected to the output of the write evaluation decoder. The first group input of the write evaluation decoder is connected to the data bus of the microcomputer and its second group input is connected to the address bus of the microcomputer. The transmission output of the counter is connected to the input of the initialization and signaling circuit, the first output of which is connected to the initialization line of the microcomputer. Preferably, the second output of the initialization and signaling circuit is connected to the input of the light signaling diode.

The advantage of the circuit for evaluating the operation of the microcomputer according to the invention lies in comparison with known circuits in the simplification of the circuit solution, i.e. reduction of the number of components,

The attached drawing shows a wiring diagram for evaluating the operation of the microcomputer.

The output 11 of the clock frequency generator 1 is connected to the counter input 21 of the counter 2, the first, second, third and fourth preset inputs 22, 23, 24 and 25 of which are connected individually to the corresponding first, second, third and fourth outputs 51, 52, 53. and 54 a preset switch 5 and further whose asynchronous recording input 26 is connected to the output 33 of the write evaluation decoder 2. The first group input 31 of the write evaluation decoder 2 is connected to the data bus 6 of the microcomputer. The second group input 32 of the write evaluation decoder 3 is connected to the address bus 7 of the microcomputer. The transmission output 27 of the counter 2 is connected to the input 41 of the initialization and signaling circuit 4, the first output 42 of which is connected to the initialization line 8 of the microcomputer. The second output 43 of the initialization and signaling circuit 4 is connected to the input 91 of the light signaling diode 2 ·

The wiring function for evaluating the operation of the microcomputer is as follows: if the microcomputer is functioning properly, certain sections of the program are cyclically executed. An instruction to write to the microcomputer evaluation circuit CS 277613 B6 en is inserted into these sections. The write evaluation decoder 2 evaluates this instruction and activates with its output 33 the asynchronous recording input 26 of the counter 2 · 0 ° of the counter 2 the preset value from the preset switch 5 is written. From this moment, the counter 2 starts counting the pulses generated by the clock frequency generator 1. The value preset by the preselection switch 5 must be set so that a new write made by the microcomputer program enters the microcomputer operation evaluation circuit before the counter 2 generates a transmission pulse at its transmission output 27 (i.e. before the counter 2 counts to its zero value at counting backwards or to its maximum value when counting forwards). If for any reason the microcomputer program violates the sequence of executed instructions so that the above-mentioned critical sections of the program will not be executed, counter 2 counts up to its maximum (when counting forward) resp. minimum value (when counting backwards) and generates a transmission pulse at its transmission output 27, which is processed by the initialization and signaling circuit 2 by generating an initialization pulse of a microcomputer at its first output 42, which resets the system and at the second output 43 it changes the output level of the signal so that the light signaling diode 9 lights up.

The circuit for evaluating the operation of a microcomputer according to the invention is intended for use in electronic modules of a kit of automation means for controlling technological objects, for example for rack stackers or ship engine drives.

Claims (2)

A circuit for evaluating the operation of a microcomputer, characterized in that the output (11) of the clock frequency generator (1) is connected to a counting input (21) of the counter (2), the first, second, third and fourth inputs (22, 23, 24 and 25) of the preset is connected to the first, second, third and fourth outputs (51, 52, 53 and 54) of the preset switch (5), the asynchronous recording input (26) of the counter (2) being connected to the output (33). a write evaluation decoder (3), the first group input (31) of which is connected to the data bus (6) of the microcomputer, while the second group input (32) of the write evaluation decoder (3) is connected to the address bus (7) of the microcomputer, the transmission output (27) the counter (2) is connected to the input (41) of the initialization and signaling circuit (4), the first output (42) of which is connected to the initialization line (8) of the microcomputer. The circuit for evaluating the operation of a microcomputer according to claim 1, characterized in that the second output (43) of the initialization and signaling circuit (4) is connected to the input (91) of the light signaling diode (9).