Abstract: A clock frequency divider circuit 11 according to the present invention generates an output clock signal obtained by dividing a frequency of an input clock signal into N/S by masking (S-N) clock pulses from S clock pulses of the input clock signal based on a frequency division ratio defined as N/S. The clock frequency divider circuit 11 includes a mask control circuit that generates a mask signal in which a non-mask timing is preferentially assigned to a clock pulse at a timing at which no clock pulse exists in a clock signal used in a circuit Ai other than a target circuit Bi using the output clock signal among S clock pulses of the input clock signal, and a mask circuit that generates the output clock signal by masking a clock pulse of the input clock signal according to the mask signal generated by the mask control circuit.

Abstract: [Objective] To provide a digital filter circuit and a digital filter control method which are capable of reducing circuit scale and power consumption for filter processing in a frequency domain such as an overlap FDE method.

Abstract: Provided is a pipeline circuit capable of flexibly controlling clock frequencies regardless of whether a pipeline operation by a flow control is stopped or not, without significantly increasing a processing latency even if a clock frequency is decreased, and in response to performance requests for a processing throughput. Among P clocks (P is a positive integer), the phases of which are delayed in the order from a first clock to a P-th clock, for example, among six clocks of P0 to P5, two successive clocks, the phases of which are delayed from each other by a predetermined phase, are allocated to a plurality of stages, for example, five-stage pipeline buffers 32a to 32e, in the order from a previous stage to a subsequent stage, and also are allocated so that one clock signal having an identical phase is shared between two adjacent pipeline buffers.

Abstract: To provide a clock frequency divider circuit that generates a clock signal enabling an expected proper communication in communication with a circuit operating by a clock having a different frequency. A clock frequency division circuit according to the present invention generates an output clock signal obtained by dividing a frequency of an input clock signal into N/S by subtracting (S?N) clock pulses from S clock pulses of the input clock signal based on a frequency division ratio defined as N/S. The clock frequency division circuit generates a control signal used to preferentially subtract a clock pulse at a timing other than a communication timing of data communication performed by a target circuit using the output clock signal among S clock pulses of the input clock signal. Further, it generates the output clock signal by subtracting a clock pulse of the input clock signal according to the generated control signal.

Abstract: To provide a clock frequency divider circuit that generates a clock signal enabling an expected proper communication in communication with a circuit operating by a clock having a different frequency. A clock frequency division circuit according to the present invention generates an output clock signal obtained by dividing a frequency of an input clock signal into N/S by subtracting (S?N) clock pulses from S clock pulses of the input clock signal based on a frequency division ratio defined as N/S. The clock frequency division circuit generates a control signal used to preferentially subtract a clock pulse at a timing other than a communication timing of data communication performed by a target circuit using the output clock signal among S clock pulses of the input clock signal. Further, it generates the output clock signal by subtracting a clock pulse of the input clock signal according to the generated control signal.

Abstract: A clock frequency divider circuit in accordance with the present invention is capable of generating a clock signal that makes it possible to perform an expected proper communication operation in communication with a circuit operating by a clock having a different frequency, and includes a mask control circuit 20 and a mask circuit 10. The mask control circuit 20 includes a mask timing signal generation circuit 22 that generates a mask timing signal 29 used to preferentially mask a clock pulse at a timing other than communication timings among M clock pulses of the input clock signal based on a communication timing signal 26, and a mask restraint circuit 62 that carries out a process to restrain masking of a clock pulse at a communication timing. The mask circuit 10 generates an output clock signal by masking clock pulses of an input clock signal according to a mask signal 50 generated by the mask control circuit.

Abstract: A mask circuit (10) masks the clock pulses of a clock S in accordance with an input mask signal (50), generating and outputting a clock B. A mask control circuit (20) generates a mask signal (50) which assigns mask timings to mask (M?N) clock pulses, to timings other than communication timings to perform data communication, out of the timings of M successive clock pulses of the clock S, based on communication timing information (30) indicating the communication timings of data communication that is performed with a circuit A by a circuit B using the clock B. The mask control circuit (20) then outputs the mask signal (50) to the mask circuit (10).

Abstract: A clock converting circuit (1) receives and then converts m-phase clocks of a frequency f having a phase difference of 1/(f×m) to n-phase clocks of the frequency f having a phase difference of 1/(f×n). A single-phase clock generating circuit (2) receives the n-phase clocks of the frequency f having a phase difference equivalent time of 1/(f×n) to generate single-phase clocks in synchronism with the rising or falling edges of the n-phase clocks. Since the frequency of the m-phase clocks inputted to the clock converting circuit (1) is ‘f’, if a desired frequency of the single-phase clocks is decided, then ‘n’ can be obtained from the equation: the frequency of the single-phase clocks is equal to (f×n). This value of ‘n’ is set to the clock converting circuit (1), thereby obtaining the n-phase clocks of the frequency f from the m-phase clocks of the frequency f to provide single-phase clocks of a desired frequency.

Abstract: Provided is a semiconductor integrated circuit and an exponent calculation method that, when normalizing a plurality of data by a common exponent, speed up exponent calculation and reduce circuit scale and power consumption. When normalizing a plurality of data by a common exponent, a semiconductor integrated circuit calculates the exponent of the plurality of data. Included is a bit string generator that generates a second bit string containing bits having a transition value indicating that values of adjacent bits are different or a non-transition value indicating that values of adjacent bits are not different for each pair of adjacent bits of a first bit string constituting the data, and an exponent calculator that calculates the exponent of the plurality of data based on bit position of the transition value of a plurality of second bit strings generated from a plurality of first bit strings respectively constituting the plurality of data.

Abstract: Provided is a pipeline circuit capable of flexibly controlling clock frequencies regardless of whether a pipeline operation by a flow control is stopped or not, without significantly increasing a processing latency even if a clock frequency is decreased, and in response to performance requests for a processing throughput. Among P clocks (P is a positive integer), the phases of which are delayed in the order from a first clock to a P-th clock, for example, among six clocks of P0 to P5, two successive clocks, the phases of which are delayed from each other by a predetermined phase, are allocated to a plurality of stages, for example, five-stage pipeline buffers 32a to 32e, in the order from a previous stage to a subsequent stage, and also are allocated so that one clock signal having an identical phase is shared between two adjacent pipeline buffers.

Abstract: Provided is a communication circuit (10) connected with a plurality of function blocks (A, B) that perform processing based on a first clock signal, and mediates communication between the function blocks (A, B). The communication circuit (10) includes N number of communication means, where N is a positive integer, having the same data width as communication data output from the function blocks, and each of the N number of communication means performs communication processing based on N number of second clock signals specified by 1/N of a frequency of the first clock signal, respectively corresponding to the N number of communication means and having a phase difference of 360/N degrees from each other. This makes it possible to provide a communication circuit between function blocks in which the amount of necessary hardware and power consumption is small, the timing design is easy, and the communication latency is low.

Abstract: To provide a rational frequency dividing circuit wherein the variations in cycle times of frequency divided clock signals are small, there are many occasions in which the minimum cycle time of frequency divided clock signals and test costs are small. A clock signal frequency dividing circuit, the frequency division ratio of which is specified as N/M where are both N and M are integers, includes an output clock selecting circuit (200) that selects one of three situations: an input clock signal is outputted as it is, the input clock signal is inverted and outputted and the input clock signal is not outputted; and a clock selection control circuit (100) that generates a control signal for controlling the foregoing selection of the output clock selecting circuit. The clock selection control circuit controls the foregoing selection of the output clock selecting circuit at every cycle of the input clock signal.

Abstract: A clock frequency divider circuit in accordance with the present invention is capable of generating a clock signal that makes it possible to perform an expected proper communication operation in communication with a circuit operating by a clock having a different frequency, and includes a mask control circuit 20 and a mask circuit 10. The mask control circuit 20 includes a mask timing signal generation circuit 22 that generates a mask timing signal 29 used to preferentially mask a clock pulse at a timing other than communication timings among M clock pulses of the input clock signal based on a communication timing signal 26, and a mask restraint circuit 62 that carries out a process to restrain masking of a clock pulse at a communication timing. The mask circuit 10 generates an output clock signal by masking clock pulses of an input clock signal according to a mask signal 50 generated by the mask control circuit.

Abstract: To provide a clock frequency divider circuit that generates a clock signal enabling an expected proper communication in communication with a circuit operating by a clock having a different frequency. A clock frequency division circuit according to the present invention generates an output clock signal obtained by dividing a frequency of an input clock signal into N/S by subtracting (S?N) clock pulses from S clock pulses of the input clock signal based on a frequency division ratio defined as N/S. The clock frequency division circuit generates a control signal used to preferentially subtract a clock pulse at a timing other than a communication timing of data communication performed by a target circuit using the output clock signal among S clock pulses of the input clock signal. Further, it generates the output clock signal by subtracting a clock pulse of the input clock signal according to the generated control signal.

Abstract: A clock frequency divider circuit 11 according to the present invention generates an output clock signal obtained by dividing a frequency of an input clock signal into N/S by masking (S-N) clock pulses from S clock pulses of the input clock signal based on a frequency division ratio defined as N/S. The clock frequency divider circuit 11 includes a mask control circuit that generates a mask signal in which a non-mask timing is preferentially assigned to a clock pulse at a timing at which no clock pulse exists in a clock signal used in a circuit Ai other than a target circuit Bi using the output clock signal among S clock pulses of the input clock signal, and a mask circuit that generates the output clock signal by masking a clock pulse of the input clock signal according to the mask signal generated by the mask control circuit.

Abstract: A mask circuit (10) masks the clock pulses of a clock S in accordance with an input mask signal (50), generating and outputting a clock B. A mask control circuit (20) generates a mask signal (50) which assigns mask timings to mask (M?N) clock pulses, to timings other than communication timings to perform data communication, out of the timings of M successive clock pulses of the clock S, based on communication timing information (30) indicating the communication timings of data communication that is performed with a circuit A by a circuit B using the clock B. The mask control circuit (20) then outputs the mask signal (50) to the mask circuit (10).

Abstract: It is possible to provide a highly reliable semiconductor device and a communication method in which communication can be performed between circuits with a large degree of freedom of clock frequency which can be set in each of the circuits, a decisive operation, and a small communication latency. The semiconductor device according to the present invention includes a first circuit that performs processing based on a first clock signal, the first clock signal having a frequency M/N times as large as a frequency of a second clock signal (N is a positive integer, and M is a positive integer larger than N); a second circuit that performs processing based on the second clock signal; and a communication timing control circuit that generates a communication timing signal to control a timing at which the first circuit performs communication with the second circuit.

Abstract: A clock signal dividing circuit in which a dividing ratio is regulated by N/M (M and N are positive integers and satisfy M>N) includes: a variable delay circuit which gives a predetermined delay amount based on a control value to an input clock signal CKI to output an output clock signal CKO; and a variable delay control circuit which cumulatively adds values obtained by subtracting N from M every cycle of the input clock signal CKI, when the addition result is N or more, performs a calculation which subtracts N from the addition result to obtain a calculation result K, and calculates, to a maximum delay amount in the variable delay circuit corresponding to one cycle of the input clock signal CKI, a control value corresponding to a delay amount of K/N of the maximum delay amount to give the control value to the variable delay circuit.

Abstract: The present invention relates to a technique capable of establishing communications between cores, which can provide a large degree of freedom of clock frequencies settable in each core, and thus providing deterministic operation, small communication latency, and high reliability. An object of the present invention is to provide a semiconductor device with high reliability, by analyzing factors affecting the performance of the semiconductor device, based on the communication histories within the semiconductor device, and reflecting the analysis back to the next generation semiconductor devices. The improved semiconductor device includes a core A for transmitting data in sync with the clock signal clkA, a core B for receiving data in sync with the clock signal clkB coincided with the rising or falling of the clock signal clkA in a constant period, and a controller for controlling communications between the core A and the core B.

Abstract: A clock signal dividing circuit in which a dividing ratio is regulated by N/M (M and N are positive integers and satisfy M>N) includes: a variable delay circuit which gives a predetermined delay amount based on a control value to an input clock signal CKI to output an output clock signal CKO; and a variable delay control circuit which cumulatively adds values obtained by subtracting N from M every cycle of the input clock signal CKI, when the addition result is N or more, performs a calculation which subtracts N from the addition result to obtain a calculation result K, and calculates, to a maximum delay amount in the variable delay circuit corresponding to one cycle of the input clock signal CKI, a control value corresponding to a delay amount of K/N of the maximum delay amount to give the control value to the variable delay circuit.