SU1408458A1 - Storage retaining information in case of power fault - Google Patents

Abstract

The invention relates to storage devices and is intended for the secure storage of information in digital computing systems, in particular in systems with redundancy. The purpose of the invention is to increase the reliability of the device. The device contains an accumulator 1, a switch 2, a backup power source 3, an isolation element 8, an output 9 for connecting the main power source, a differentiating element 10, threshold elements 11, 12, 13, element 14 with corresponding connections. In the device, there is a constant tracking of the voltage variation of the main power source, which avoids an individual adjustment of the delay time. Iodine is a specific system configuration that is powered from a single power source. 2 Il. i SL

Description

4iib

X

4i SL

00

ue.f

one

The invention relates to memory devices and is intended for the secure storage of information in digital computing systems, in particular, in redundant systems.

The aim of the invention is to improve the reliability of the device.

Figure 1 shows the block diagram of the device; Fig. 2 shows the time dependence of: a) the voltage of the main power source; b) the unlock signal of the accumulator (attached to the control inputs of the switches) of the proposed device.

The proposed device contains accumulator 1, the blocking input of which is connected to the output of the interrupter 2, connected by its first information input with the backup source 3 of the power supply, connected, in addition, to the power input of the accumulator. The second information input of switch 2 is connected to the control input 4 of the device, and the address input 5f of the information input 6 and the information output 7 of the accumulator are the address, information inputs and information output of the device. The isolation element 8 is connected by one output to the backup power source, and the other to the output of the device for connecting the main power supply 9 and to the inputs of differentiating element 10, first and third threshold elements 11 and 12. Output D1) of the potentiating element is connected the input of the second threshold element 13), and the outputs of all three threshold elements are connected to the inputs of the element 14 that is loaded on the control input of the switch

The proposed device works as follows.

The threshold elements 11-13 compare the voltages applied to their inputs with the reference voltage levels specified when setting up the system. If the input voltage is less than the reference level, then the output of the threshold element .11 maintains a low voltage level O, and if the input voltage of the reference output exceeds the threshold element 11 is set to a high voltage level 1. If the input voltage of the threshold elements

0

five

0 5 o

Commands 12 and 13 are less than the reference levels, then at the output of the i-cc, level 1 is maintained, and if more, then level O

In the automatic mode, when there is no voltage of the main source 9, the outputs of the threshold elements 11-13 are in the low level O, and therefore the output of the element I is maintained. The state O. The switch 2 in this state of the control inputs commutes To the control input of the accumulator 1 a high level signal from the backup source 3 of the power supply. There is a storage recorded in the storage of information, and access to the drive is blocked.

When switching to the main source 9, the voltage of the latter Ug gradually increases due to the inertia of the load, and the increase is generally oscillatory in nature (Fig. 2a). When the voltage is applied to the voltage at the output of the main source 9 of the level U, at which the first threshold element 11 is triggered, the output of the latter produces a high level signal 1, which is fed to the third input of the And 14 element.

n Uboc. ,

(one)

conditions

where and „„ „is the nominal voltage

NOM

main food source.

The threshold element 13 forms at its output a high level signal, provided that the voltage on

 one

its input U is less than the specified U, and since the input voltage of the threshold element 13 is the output voltage of the differentiating element 10, the condition

and

dUe, dt

conditions

where and is the voltage on the outputs of the

new source of nutrition.

Thus, the threshold element 13 compares with the reference level a voltage proportional to the rate of change of voltage at the output of the main power source. In this case, the support level U is selected from

n

- (yy.) Mt

S40

f-) 3-set rate of change Uo, chosen from the condition that the transition process approached its steady-state value so that it can be considered complete.

ultimately, in the code of the poro element 13, it is maintained when the condition

 lf - b ...

At the output of the threshold element 12, a high level signal 1 is maintained when the condition

and

"

 and

nom

where and

Hefi

nominal voltage of the main power source.

Thus, at the output of the element And 14 there is a level 1 with simultaneous fulfillment of the conditions (1), (2) and (3). The presence of level 1 at the control inputs of switches 2 and 3 corresponds to the switching to the control inputs of accumulator 1 of external control signals, i.e. unlocking a storage device 1. In a known device, unlocking occurs when the supply voltage reaches a threshold level and.

In the proposed device, the drive is unlocked when the transition

Uhom

with

the process will enter the zone tU with a speed not greater than the specified one (Fig. 2a, b

The conditions for inequalities (1) and (3) are chosen to avoid false unlocking of the accumulator at the maximum and minimum points of the transition process, respectively.

Thus, the process of unlocking drive 1 is controlled while the voltage of the main power supply is constantly monitored. In the known device; Such tracking is absent, therefore: with the optimal setting of the delay time when using one

ten

15

20

25

thirty

This time will not be optimal for another source or when the nature of the source load changes, which manifests itself when connected to a system in which the memory device, additional modules work and when the load parameters change with time (aging). If the delay time .t is chosen to be obviously longer than optimal, then the minimum time of the known device will not be ensured, which does not allow its use in systems with redundancy (namely, such systems most often use self-powered storage devices).

To differentiate the voltage of the transient process from the false alarms of the system from high-frequency impulse noise, usually present in real systems, the transfer function (W (S)) of the differentiating element can be selected as follows:

+ 1

(g) (, j.

S + 1)

(four)

t ..

35 40

)

45

50

55

where T. is the constant of the time of differentiation, chosen from the speed of the transient process;

T is the integration time constant, chosen from the condition of the highest suppression of high-frequency interference and dependent on the spectral characteristics of the interference; T is the time constant chosen from the maximum possible speed of a single process and limiting the upper frequency of the differentiated signal. As a result of the prepositional changes in the storage device circuit while preserving information when the power is turned off, it is concluded that sequentially connected differentiating and second threshold elements, as well as the third threshold element are entered into it, and the inputs of the differentiating element and the third threshold element are connected

Claims (1)

A memory device with saving information when the power is turned off, containing a drive, an isolation element, a first threshold element, an AND element, a switch and a backup power source, the output of which is connected to the drive power input, the first information input of the switch and one of the outputs of the isolation element, another output which is connected to the input of the first threshold element and is the output of the device for connecting the main power source, the output of the first threshold element is connected to. the first inputs of the element And, the output of which is connected to the input of the switch, the output. which is connected to the drive lock input, the second information input of the switch is the control input of the device, the address and information inputs and the information output of the drive are the corresponding inputs and outputs of the device, characterized in that, in order to increase the reliability of the device, differentiating element and a second threshold element, the third threshold element ', and the inputs of the differentiating element and the third threshold element are connected to the output roystva to connect the main power source, the outputs of the second and third threshold elements are connected to second and third input element I.