Simulink Reference

Shift Arithmetic

Shift the bits and/or binary point of a signal

Library

Logic and Bit Operations

Description

The Shift Arithmetic block can be used to shift the bits or the binary point of a signal, or both.

For example, the effects of binary point shifts two places to the right and two places to the left on an input of data type sfix(8) are shown below.

Shift Operation	Binary Value	Decimal Value
No shift (original number)	11001.011	-6.625
Binary point shift right by two places	1100101.1	-26.5
Binary point shift left by two places	110.01011	-1.65625

This block performs arithmetic bit shifts on signed numbers. Therefore, the most significant bit is recycled for each bit shift. The effects of bit shifts two places to the right and two places to the left on an input of data type sfix(8) follow.

Shift Operation	Binary Value	Decimal Value
No shift (original number)	11001.011	-6.625
Bit shift right by two places	11110.010	-1.75
Bit shift left by two places	00101.100	5.5

Data Type Support

The Shift Arithmetic block accepts signals of any data type supported by Simulink, including fixed-point data types, except boolean type.

Parameters and Dialog Box

Shift bits right how many places (negative is shift left)

The number of places the bits of the input signal is shifted. A positive value indicates a shift right, while a negative value indicates a shift left.

Shift binary point right how many places (negative is shift left)

The number of places the binary point of the input signal is shifted. A positive value indicates a shift right, while a negative value indicates a shift left.

Characteristics

Direct Feedthrough	Yes
Sample Time	Inherited
Scalar Expansion	Yes

S-Function Builder

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