Nec Electronics Corporation

Renesas Electronics Corporation

Tomokazu Kondo

Keisuke Nomura

Yousuke Sasaki

In one cycle for transferring data, a controller forming a data transfer circuit stores pointer information P_A for periodic transfer and pointer information P_B for non-periodic transfer read from a memory respectively in first and second storage areas. The controller sequentially transfers, to a communication bus, data D_A for periodic transfer and data D_B for non-periodic transfer read from the memory by referring to the P_A and P_B. If transfer by a data length indicated in the P_B has not been completed upon the transfer of the D_B, the controller updates the data length to a data length of the remaining data, and updates an address indicated in the P_B to an address on the memory of the remaining data. In the next cycle for transferring data, the controller reads the remaining data from the memory by referring to the P_B, and transfers the remaining data to the communication bus.

Periodic and non-periodic data transfer circuit analyzing pointer information

Disclosed is a digital variable oscillator which has: a cycle change detector for detecting the change of cycle between two input data; a decoder for outputting a predetermined signal in relation to the detection result of the cycle detector; an adder for adding signal output from the decoder a predetermined time; and a frequency adjuster for adjusting the frequency of window signal in relation to the addition result of the adder.

Digital variable frequency oscillator

Disclosed is a digital VFO device which comprises a plurality of VFO circuits and ; synchronous counters and installed in each VFO circuits and ; and an adjusting circuit selecting one of the VFO circuits and based on signals and representing the peak shift state of an input data output from each VFO circuits. Correcting instruction signals and are generated to correct the synchronous counter of the other VFO circuits by substituting the counter value of the synchronous counter of the VFO circuit selected by the adjusting circuit for the synchronous counter of the other VFO circuits.

Digital VFO device

A digital VFO phase control device comprising: an output signal generation means for generating an output signal having the predetermined phase relationship with an input signal of the digital VFO phase control device, a phase difference detection means for detecting a phase difference between the input signal and the output signal, a first correction value output means for outputting a correction value for correcting a phase of the output signal based on a phase difference detected by the phase difference detection means, a second correction value output means for outputting a preset correction value for correcting a phase of the output signal based on a phase difference detected by the phase difference detection means, a comparison means for detecting whether or not the phase difference detected by the phase difference detection means being within a predetermined range, and a correct value selection means for selecting either one of a correction value outputted by the first correction value output means and a correction value outputted by the second correction value output means based on a comparison result of the comparison means, and controlling a phase of the output signal.

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Kanagawa, Japan

Tomokazu Kondo