RECONFIGURABLE CIRCUIT USING VALID SIGNALS AND METHOD OF OPERATING RECONFIGURABLE CIRCUIT

1 . A reconfigurable circuit, comprising:

a data execution unit including a plurality of execution elements, each of which performs execution with respect to plural data upon the plural data being all in a valid state, and holds valid-state output data indicative of a result of the execution at an output node thereof while all the plural data are in the valid state;

a data selecting unit configured to connect between the execution elements in a reconfigurable manner; and

a data input unit configured to store data as input data that are supplied to a series of execution elements connected through the data selecting unit to perform a series of executions,

wherein a valid or invalid state of given data is specified by a valid signal indicative of a valid or invalid state, the valid signal accompanying and forming a pair with the given data, and the input data supplied from the data input unit to the data execution unit are fixed to valid-state constant data while the series of executions are performed.

2 . The reconfigurable circuit as claimed in claim 1 , further comprising an execution completion detection unit configured to assert an execution completion detection signal upon one or more execution results of the series of executions being all simultaneously in a valid state.

3 . The reconfigurable circuit as claimed in claim 2 , wherein, in response to the assertion of the execution completion detection signal, the data input unit stops supplying valid-state data to the data execution unit.

4 . The reconfigurable circuit as claimed in claim 2 , wherein the data selecting unit includes a plurality of output ports connected to the execution completion detection unit, and supplies signals indicative of a valid or invalid state of the one or more execution results of the series of executions to the execution completion detection unit through one or more of the output ports,

and wherein the execution completion detection unit is configured to select one or more of the output ports that are taken into consideration when deciding whether the signals indicative of a valid or invalid state all indicate a valid state simultaneously.

5 . The reconfigurable circuit as claimed in claim 1 , further comprising a control unit configured to assert a start indicating signal indicative of start of the series of executions to the data input unit, wherein in response to the assertion of the start indicating signal, the data input unit starts supplying valid-state data to the data execution unit.

6 . A method of operating a reconfigurable circuit, comprising:

a data execution unit including a plurality of execution elements, each of which performs execution with respect to plural data upon the plural data being all in a valid state, and holds valid-state output data indicative of a result of the execution at an output node thereof while all the plural data are in the valid state;

a data selecting unit configured to connect between the execution elements in a reconfigurable manner; and

a data input unit configured to store data as input data that are supplied to a series of execution elements connected through the data selecting unit to perform a series of executions,

the method comprising:

causing the input data supplied from the data input unit to the data execution unit to be fixed to valid-state constant data while the series of executions are performed.

7 . The method as claimed in claim 6 , further comprising asserting an execution completion detection signal upon one or more execution results of the series of executions being all simultaneously in a valid state.

8 . The method as claimed in claim 7 , further comprising stopping supplying valid-state data from the data input unit to the data execution unit in response to the assertion of the execution completion detection signal.

9 . The method as claimed in claim 7 , further comprising:

supplying signals indicative of a valid or invalid state of the one or more execution results of the series of executions through one or more of output ports of the data selecting unit; and

selecting one or more of the output ports that are taken into consideration when deciding whether the signals indicative of a valid or invalid state all indicate a valid state simultaneously.

10 . The method as claimed in claim 6 , further comprising starting supplying valid-state data from the data input unit to the data execution unit in response to the assertion of a start indicating signal indicative of start of the series of executions.

11 . A reconfigurable circuit, comprising:

a data execution unit including a plurality of execution elements, each of which latches plural data in a simultaneous or sequential manner in an order in which the plural data become valid, and performs execution with respect to the plural data upon the plural data being all latched, thereby outputting valid-state data indicative of a result obtained by the execution;

a data selecting unit configured to connect between the execution elements in a reconfigurable manner; and

a data input unit configured to store data as input data that are supplied to a series of execution elements connected through the data selecting unit to perform a series of executions,

wherein a valid or invalid state of given data is specified by a valid signal indicative of a valid or invalid state, the valid signal accompanying and forming a pair with the given data,

12 . The reconfigurable circuit as claimed in claim 11 , further comprising an execution completion detection unit configured to assert an execution completion detection signal upon one or more execution results of the series of executions being all in a valid state.