SU1552176A1 - Device for subtraction of decimal numbers - Google Patents

Abstract

The invention relates to computing and measuring technology and can be used to build arithmetic and modernize measuring digital devices. The purpose of the invention is to simplify the device. The device contains the elements EXCLUSIVE OR 1, 2, binary adders 3, 4 and trigger 7. 1 Il.

Description

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The invention relates to computing and measuring technology and can be used to build arithmetic and modernize measuring digital devices.

The purpose of the invention is to simplify the device.

The drawing shows a schematic diagram of the device.

The device contains, in each bit, the elements EXCLUDE OR 1 and 2 of the first and second groups, the first binary adder 3, the second binary adder A, the outputs 5 of the binary-decimal value of the difference code, the outputs of transfer 6, the trigger 7, the output 8 characters.

ten

Device way.

works as follows

9 of the initial state, trigger 7 is requested and the signal levels of Q O, Q 1 are set at its outputs,

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at the same time, the elements EXCLUSIVE OR 2 invert the operand of the subtracted N ,, and the adder 3 operates in the detractor mode of the binary code. The result of the difference of the three most significant bits S2, S3, S is fed to the inputs of the three lower bits of the first term of the adder k, and the least significant bit S1 is the lowest bit (2e) of the result. The adder corrects the code so that, depending on the transfer signal from the adder 3, either the number 15 or

the number 12, which is summed with the first term, corrected also by the higher bit, and at the outputs of the three lower digits of the adder

2Q k is a binary-decimal code (24,, 23), and the most significant bit Sk is a carry signal for intermediate calculations or a sign to form the difference sign via

25 trigger 7.

Example.

1) 83-59 21 dess. 0010

(2)

0100 rep.des.

0

2) 59 - 83 "-2k

Turning on

trigger

In this case, the signal Sk 0 on the combiner is the output of the younger one on trigger 7, which, through the binary-decimal code bit, breaks the EXCLUSIVE OR 1 inverts the device numbers, the outputs of the three start Nz and the difference becomes equal to their bits are connected to the inputs

the signal Q O of the trigger is indicated by the three least significant bits of the first term of 2V, and the sign

-2

second adder, and the transfer output is connected to the inputs of the higher

Claims (1)

Invention Formula Devices for subtracting decimal numbers, containing in each bit the first and second binary adders and EXCLUSIVE OR elements, characterized in that, in order to simplify the device, it contains a trigger, and the inputs of the first adder are connected to the outputs of the EXCLUSIVE OR elements of the first and second groups , the first inputs of which are connected to the inputs of the corresponding tetrads of the decimal bits of the operands of the decremented and subtracted device by the output of the device sign. va, exit of the younger bit of the first Compiled by A. Klyuev -1 1: TRASH Tehred L. Oliynyk Proofreader S. Cherni Order 330tirage 558Signature VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 second adder, and the transfer output is connected to the inputs of the higher the bits of the first and two lower bits of the second term of the second adder, the outputs of the three lower bits of which are connected to the outputs of the three higher bits of the binary-decimal device difference code, and the output of the high bit is the output of the transfer signal to the high bit of the device, transfer output of the highest bit device connected to the trigger input, the direct and inverse outputs of which are connected to the second inputs of the EXCLUSIVE OR elements of the first and second groups, the inverse output of the trigger is output sign device.