Abstract: Provided is a communication system capable of transmitting an emergency notification with a short delay without waiting until the completion of a current transmission of a frame or retransmitting the frame. The communication system includes a transmission device for generating a frame compliant with the Ethernet standard and transmitting the frame to the outside of the device, and a reception device for receiving the frame. The transmission device inserts emergency notification data into the frame at predetermined data intervals. The reception device acquires the emergency notification data from the received frame at the same data intervals as the transmission device, and acquires the remaining data as data (normal data) in a header region and payload region of the frame.

Abstract: The present invention solves a problem that the phases of clocks obtained by frequency-dividing PLL clocks output from local PLL circuits cannot be made the same in a plurality of data transfer blocks. A local PLL circuit outputs a PLL clock obtained by multiplying a common external clock. A frequency divider outputs a feedback clock obtained by frequency-dividing the PLL clock to the local PLL circuit. An FIFO buffer temporarily holds data input from the outside. The FIFO buffer outputs the held data on the basis of a frequency-divided PLL clock. A clock generator generates a frequency-divided PLL clock obtained by frequency-dividing the PLL clock. The clock generator controls the phase of the frequency-divided PLL clock on the basis of a common start signal.

Abstract: Provided is a communication system capable of transmitting an emergency notification with a short delay without waiting until the completion of a current transmission of a frame or retransmitting the frame. The communication system includes a transmission device for generating a frame compliant with the Ethernet standard and transmitting the frame to the outside of the device, and a reception device for receiving the frame. The transmission device inserts emergency notification data into the frame at predetermined data intervals. The reception device acquires the emergency notification data from the received frame at the same data intervals as the transmission device, and acquires the remaining data as data (normal data) in a header region and payload region of the frame.

Abstract: The present invention solves a problem that the phases of clocks obtained by frequency-dividing PLL clocks output from local PLL circuits cannot be made the same in a plurality of data transfer blocks. A local PLL circuit outputs a PLL clock obtained by multiplying a common external clock. A frequency divider outputs a feedback clock obtained by frequency-dividing the PLL clock to the local PLL circuit. An FIFO buffer temporarily holds data input from the outside. The FIFO buffer outputs the held data on the basis of a frequency-divided PLL clock. A clock generator generates a frequency-divided PLL clock obtained by frequency-dividing the PLL clock. The clock generator controls the phase of the frequency-divided PLL clock on the basis of a common start signal.

Abstract: The present invention solves a problem that the phases of clocks obtained by frequency-dividing PLL clocks output from local PLL circuits cannot be made the same in a plurality of data transfer blocks. A local PLL circuit outputs a PLL clock obtained by multiplying a common external clock. A frequency divider outputs a feedback clock obtained by frequency-dividing the PLL clock to the local PLL circuit. An FIFO buffer temporarily holds data input from the outside. The FIFO buffer outputs the held data on the basis of a frequency-divided PLL clock. A clock generator generates a frequency-divided PLL clock obtained by frequency-dividing the PLL clock. The clock generator controls the phase of the frequency-divided PLL clock on the basis of a common start signal.

Abstract: The present invention solves a problem that the phases of clocks obtained by frequency-dividing PLL clocks output from local PLL circuits cannot be made the same in a plurality of data transfer blocks. A local PLL circuit outputs a PLL clock obtained by multiplying a common external clock. A frequency divider outputs a feedback clock obtained by frequency-dividing the PLL clock to the local PLL circuit. An FIFO buffer temporarily holds data input from the outside. The FIFO buffer outputs the held data on the basis of a frequency-divided PLL clock. A clock generator generates a frequency-divided PLL clock obtained by frequency-dividing the PLL clock. The clock generator controls the phase of the frequency-divided PLL clock on the basis of a common start signal.