JPH0332108A - Two-dimension digital filter circuit - Google Patents

Abstract

PURPOSE:To exclude a waste for a processing time and to attain high speed operation by providing 1st and 2nd coded digit number use multipliers and a coded digit number.twos complement display binary number converter and executing only once the conversion into a twos complement binary number. CONSTITUTION:An output of a 1st coded digit number use product sum computing element 1 is a coded digit number and it is inputted to a 2nd coded digit number use product sum computing element 2 without conversion into a twos complement binary number. Then a coded digit number.twos complement display binary number converter 3 converts the coded digit number into the coded digit number twos complement display binary number to output the twos complement display binary number as the final result. Then both the 1st and 2nd product sum operate and multiplication are implemented by using the coded digit number in which the propagation of a carry signal is suppressed to one digit with high speed operation and a fast speed two-dimension digital filter circuit is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a two-dimensional digital filter circuit, and particularly to a high-speed two-dimensional digital filter circuit using signed digit numbers.

[Conventional technology]

A product-sum calculator used in a conventional two-dimensional digital filter circuit is composed of a multiplier and an accumulator that handle two-complement binary numbers for input, internal calculation, and output.

Recently, with the aim of high-speed operation, an increasing number of digital arithmetic units are employing signed digit adders in which the propagation of a carry signal requires only one digit.

A multiplier that uses a signed digit adder, an accumulator that accumulates the signed digit output of this multiplier to 11 signed digits, and a two-complement representation of the output of this accumulator. A product-sum calculator consisting of a converter and a converter for converting into a base number has also been reported (February 1989, I.E.
1989 IEEE International Solid State Circuits Conference Digest of Technical Papers (1989 IEEE IN) published by IEEE.
TERNATIONAL 5OLID-8TATE C
IRCUITS CONFERENCE DIGEST
OF TECHNICAL PAPER8) PP, 17
2-173].

FIG. 5 is a block diagram showing a conventional two-dimensional digital filter circuit constructed by cascading two product-sum calculators for signed digit numbers.

In this two-dimensional digital filter circuit, the number of signed digits output from the product-sum calculator 1 for the number of signed digits in the first stage is converted to sign M=7' (the number of digits/two-complement number is displayed once by the binary number converter 6). It is converted into a two-complement representation binary number, which is input to the product-sum calculator 5 for the number of signed digits in the second stage, and then again multiplied by the number of digits with the number ? The signed digit number/two-complement representation binary number conversion circuit 3 converts the data into a two-complement representation binary representation again, and outputs the final result.

[Problem to be solved by the invention]

Conversion from a signed digit number to a two-complement representation binary number is performed by ordinary addition with a carry signal propagated, so
It greatly affects the operating speed of the entire circuit. Therefore, as described in the section on the prior art, when a two-dimensional digital filter circuit is configured with a product-sum calculator for signed digit numbers that converts into a two-complement representation binary number and outputs it, the conversion 1
Processing time is wasted for each batch. An object of the present invention is to provide a high-speed two-dimensional digital filter circuit that eliminates this wasteful processing time.

[Means to solve the problem]

The two-dimensional digital filter circuit of the first invention includes a first signed digit number output terminal having a first two-complement representation binary number input terminal, a second two-complement representation binary number input terminal, and a first signed digit number output terminal. A product-sum calculator for the number of digits,
a second signed digit number product-sum calculator having a first signed digit number input terminal, a third two-complement representation binary number input terminal, and a second signed digit number output terminal; a signed digit number @ two complement representation binary number converter having a signed digit number input terminal and a first two complement representation binary number output terminal;
A first signed digit number output terminal of the signed digit sum calculator is connected to a first signed digit number input terminal of the second signed digit number sum calculator, Said second signed digit number 2
The signed digit number output terminal of the complement representation 2 is connected to the second signed digit number input terminal of the signed digit number/two complement representation binary number conversion 4.

The two-dimensional digital filter circuit of the second invention is
a first signed digit sum product calculator having a first two-complement display binary input terminal, a second two-complement display binary input terminal, and a first signed digit number output terminal; Signed digit number input terminal and third
a second signed digit number cycle product-sum calculator having a two-complement display binary number input terminal and a second signed digit number output terminal; a second signed digit number input terminal and a fourth two-complement number display; a signed digit frequency multiplier having a binary input terminal and a third signed digit shift 6 output terminal; Equipped with a binary number converter that displays double digit numbers and two complement numbers,
A first signed digit number output terminal of the first signed digit number sum calculator is connected to a signed digit number input terminal of the second signed digit number base/two complement number display 1, Second signed digit
A signed digit number output terminal of two complement representation 2 is connected to a second signed digit number input terminal of the signed digit multiplier, and a third signed digit number output terminal of the signed digit multiplier is connected to the signed digit number input terminal of the signed digit multiplier. A number output terminal is connected to a third signed digit number input terminal of the signed digit number/two complement representation binary number converter.

[Effect]

By adopting such a configuration, it is possible to perform both the first and second types of sum operations and multiplication using signed digit numbers that enable high-speed calculations that can suppress the propagation of carry signals to one digit. A two-dimensional digital filter circuit can be realized.

〔Example〕

FIG. 1 is a block diagram showing the configuration of the first invention of the present application. The output of the first signed digit sum product calculator 1 is a signed digit number, and this is not converted into a two-complement binary number. is input. The signed digit number/two-complement representation binary number converter 3 converts the signed digit number into a two-complement representation binary number, thereby outputting a two-complement representation binary number as the final result.

FIG. 2 is a block diagram showing the configuration of the invention of the present application @2. The output of the first signed digit sum product calculator 1 will be the number of signed digits.

This is input to the second signed digit sum operator 2 without converting it into a two-complement representation binary number. Second
The output of the signed digit sum multiplier 2 is input to a signed digit multiplier 4 corresponding to the number of signed digits. Then, the signed digit number/two-complement representation binary number converter 3 converts the signed digit number into a two-complement representation binary number, and the final result is 2.
Outputs a complemented binary number.

Next, an embodiment of the first invention of the present application will be described. FIG. 3 is a block diagram showing an embodiment of the first invention of the present application. FIG. 3 is a block diagram representing the inside of the signed digit sum product calculators 1 and 2 shown in FIG.

Output as signed digit number. In the case of a digital filter, one of the multiplier and the multiplicand is a digital signal such as an image, and the other is a filtering coefficient stored in a ROM or the like.

The output of the signed digit extension multiplier 21 is inputted to the signed digit extension adder 31 together with the output of the register 41. This signed digit adder 3
1 and the register 41 and the signed digit accumulator 51 are constructed.

The signed digit accumulator 51 and signed digit multiplier 21 constitute a first signed digit accumulator 1.

The output of the first signed digit sum product calculator 1 is:
The signed digit number 1 is input to the second signed digit sum product calculator 2.

The other input of the second signed digit sum product calculator 2 is a two-complement binary number, and is usually a filtering coefficient stored in a ROM or the like.

Hereinafter, the operation of the register 421 is the same as that of the signed digit sum product calculator 1. The output of the signed digit accumulator 52 is input to the signed digit number/two complement representation binary number converter 3.

Therefore, the signed digit number/two-complement display converter 3 outputs the final result as a two-complement display binary number.

Next, an embodiment of the second invention of this report will be described. FIG. 4 is a block diagram showing an embodiment of the second invention of the present application. FIG. 4 is a block diagram representing the inside of the signed digit sum product calculator 1.2 shown in FIG.

The operation of the signed digit sum product calculator 1 is similar to the signed digit sum product calculator 1 of the embodiment of the first invention of the present application. The operation of the product sum calculator 2 for signed digits is also similar to the operation of the product sum calculator 2 for signed digits according to the embodiment of the first invention of the present application.

The output of the signed digit multiplier 2 is a signed digit multiplier 4 with 11 signed digits.
is input. The other input of the signed digit multiplier 4 is a quantized coefficient expressed in two-complement binary representation stored in a ROM or the like.

The output of the signed digit multiplier 4 is input to a signed digit/two-complement representation binary number converter 3, and finally a two-complement representation binary number is output.

〔Effect of the invention〕

As explained above, the two-dimensional digital circuit of the present invention can eliminate wasted processing time and operate at high speed by performing conversion to two-complement binary numbers only once and for all. It has an effect.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the first invention of the present application, and FIG.
FIG. 3 is a block diagram showing an embodiment of the first invention; FIG. 4 is a block diagram showing an embodiment of the second invention; FIG. 5 is a block diagram showing a conventional two-dimensional digital filter circuit. 1.2.5... Signed digit sum product calculator, 3.6... Signed digit number/two complement number display binary number converter, 4... Multiplier for signed digits, 10.11, 14.17...2
Complement display binary number input terminal, 12, 15.18...
・Signed digit number output terminal, 13, 16.19・
.... Signed digit number input terminal, 21, 2
2, 23... Multiplier for signed digits, 31.32... Adder for signed digits, 41.42... Register, 51, 52...
...Accumulator for signed digits. 24-point number tjc Indication Binary number input Two complement number display Binary number A Power Sign Preference A Number of digits 2s' Number display Binary number input Editor diagram 24@! ttK7r% Binary input 2's complement display Binary input code Stamp Diji Soto number 2#la &, i 2 Input figure Vortex figure Z Number display 2 complement number display 2@' Number display figure

Claims (2)

[Claims] (1) First two-complement display binary input terminal and second two-complement display binary input terminal
a first product-sum calculator for signed digit numbers having a complement display binary number input terminal and a first signed digit number output terminal; a first signed digit number input terminal and a third two-complement display binary number; A second product-sum calculator for signed digit numbers having an input terminal and a second signed digit number output terminal, and a second signed digit number input terminal and a first two-complement display binary number output terminal. a signed digit number/two-complement display binary number converter, wherein the first signed digit number output terminal of the product-sum calculator for the first signed digit number is connected to the first signed digit number output terminal for the second signed digit number; It is connected to the first signed digit number input terminal of the product-sum calculator, and the second signed digit number output terminal of the product-sum calculator for the second signed digit number is connected to the signed digit number 2. A two-dimensional digital filter circuit, characterized in that it is connected to a second signed digit number input terminal of a complement representation binary number converter. (2) First two-complement display binary input terminal and second two-complement display binary number input terminal
a first product-sum calculator for signed digit numbers having a complement display binary number input terminal and a first signed digit number output terminal; a first signed digit number input terminal and a third two-complement display binary number; a second signed digit number product-sum calculator having an input terminal and a second signed digit number output terminal; a second signed digit number input terminal and a fourth two-complement representation binary number input terminal; a signed digit number multiplier having a signed digit number output terminal of 3, a signed digit number/two complement number display 2 having a third signed digit number input terminal and a first two complement number display binary number output terminal; a base number converter, wherein the first signed digit number output terminal of the first signed digit number product-sum calculator is connected to the first sign of the second signed digit number product-sum calculator. The second signed digit number output terminal of the second signed digit number multiplier is connected to the signed digit number input terminal, and the second signed digit number output terminal of the second signed digit number multiplier is connected to the second signed digit number input terminal of the signed digit number multiplier. a third signed digit number output terminal of the signed digit number multiplier is connected to an input terminal, and a third signed digit number output terminal of the signed digit number multiplier is connected to a third signed digit number input terminal of the signed digit number/two complement number display binary number converter. A two-dimensional digital filter circuit characterized in that: