US 4,396,994 A · Data shifting and rotating apparatus

Abstract

A circuit for rotating a multibit binary word in either the right or the left direction includes a scale factor decoder receiving a scale factor word which specifies the magnitude of the rotation and a direction control signal which specifies the direction of rotation and providing a shift control word which is the same as the scale factor word when a right rotation is specified but providing a shift control word which is the complement of the scale factor word when a left rotation is specified. The circuit also includes a plurality of input buffers receiving an input word and providing corresponding input data, and a one-bit rotator receiving the input data and the direction control signal and rotating the input data in the right direction by one position when a left rotation is specified or providing the input data without rotation when a right rotation is specified. In addition, the circuit includes a network receiving data from the one-bit rotator and the shaft control word and rotating the data from the one-bit rotator in only the right direction by a magnitude specified by the shift control word. Furthermore, the circuit includes a plurality of output buffers receiving the data from the network and providing an output word.

Claims10

Dependent claims

A circuit for rotating an N-bit binary word in either a first or a second direction comprising:

control means adapted to receive a plurality of scale factor signals and a direction control signal indicative of a rotation in the second direction, and responsive thereto for providing a plurality of shift control signals which are respectively the complement of the scale factor signals, the control means providing a plurality of shift control signals which are respectively the same as the scale factor signals when the direction control signal is absent;
input means adapted to receive an N-bit input word and providing corresponding N-bit input data;
one-bit rotate means adapted to receive the input data and the direction control signal and being responsive to the direction control signal for rotating the input data by one position in the first direction, the one-bit rotate means providing the input data without rotation when the direction control signal is absent;
unidirectional shift/rotate means adapted to receive data from the one-bit rotate means and the plurality of shift control signals and for rotating the data from the one-bit rotate means in the first direction by a magnitude specified by the shift control signals;
and
output means adapted to receive data from the unidirectional shift/rotate means for providing an N-bit output word which is the input word rotated according to the scale factor signals and the direction control signal.

3 more elements

A shift/rotate circuit for shifting an N-bit binary word in a first direction and for rotating the binary word in either the first or a second direction comprising:

control means adapted to receive a plurality of scale factor signals and a direction control signal indicative of a rotation in the second direction and being responsive thereto for providing a plurality of shift control signals which are respectively the complement of the scale factor signals, the control means for providing shift control signals which are respectively the same as the scale factor signals when the direction control signal is absent;
input means adapted to receive an N-bit input word and for providing corresponding N-bit input data;
one-bit rotate means adapted to receive the input data and the direction control signal and being responsive to the direction control signal for rotating the input data by one position in the first direction, the one-bit rotate means providing the input data without rotation when the direction control signal is absent;
undirectional shift/rotate means adapted to receive data from the one-bit rotate means, the plurality of shift control signals and a rotate control signal and being responsive to the rotate control signal for rotating the data from the one-bit rotate means in the first direction by a magnitude specified by the shift control signals, the unidirectional shift/rotate means shifting the data from the one-bit rotate means in the first direction by the magnitude specified by the shift control signals;
and
output means adapted to receive data from the unidirectional shift/rotate means for providing an N-bit output word which is the input word shifted or rotated according to the scale factor, direction control and rotate control signals.

3 more elements

Dependencies are inferred from the claim text.

Data shifting and rotating apparatus

Life of this patent

Data shifting and rotating apparatus

Life of this patent

Abstract

Claims10