Patent ID: 7787528
Filing Date: 2010-08-31
Classification: G06F,H03L,H04L

Abstract:
1. A transmitting/receiving device with a transmitting/receiving function performing bidirectional communication with a host, the device comprising: a synchronization control unit; a frequency generator generating a transmitting signal; and a reference signal generation source generating a reference signal, wherein the reference signal generation source is formed independently of the host, wherein the synchronization control unit detects a frequency difference of the transmitting signal with respect to a received signal from the host, outputs a frequency coordination signal reducing the difference with respect to the received signal and outputs a spread spectrum selection signal, wherein the frequency generator determines frequency of the transmitting signal based on the reference signal, controls spread mode of the transmitting signal outputted by the spread spectrum selection signal, and coordinates the frequency of the transmitting signal by the frequency coordination signal, wherein the synchronization control unit comprises a synchronization establishment unit, a frequency difference detector, and a frequency generator, wherein the synchronization establishment unit converts a signal transmitted from the host to the transmitting/receiving device into data and a clock, and outputs a synchronization establishment signal, the received signal and a reception data, wherein the frequency difference detector receives the reference signal, the synchronization establishment signal, the received signal, and a transmitting signal outputted from the frequency generator and is controlled by the synchronization establishment signal, wherein the frequency difference detector detects the frequency difference between the received signal and the transmitting signal, and outputs the frequency coordination signal and spread spectrum selection signal, wherein the frequency generator receives the reference signal, the frequency coordination signal and the spread spectrum selection signal and controls spread mode and frequency of a transmitting signal outputted based on the frequency coordination signal and the spread spectrum selection signal, wherein the frequency difference detector comprises a signal detector, a sequencer, and a frequency difference detection coordinator, wherein the signal detector to which the synchronization establishment signal is inputted judges whether synchronization is established and outputs a judgment result to the sequencer, wherein the sequencer recognizes a sequence based on the judgment result and outputs a sequence signal to the frequency difference detection coordinator, wherein the frequency difference detection coordinator to which the received signal, the transmitting signal, the reference signal and the sequence signal are inputted is controlled of its operation by the sequence signal, detects the frequency difference between the received signal and the transmitting signal at a detection time generated by the reference signal, and outputs the frequency coordination signal and the spread spectrum selection signal, wherein the frequency difference detection coordinator comprises a transmitting frequency detector, a received frequency detector, and a difference detection circuit, wherein the transmitting frequency detector to which the reference signal, the sequence signal and the transmitting signal are inputted is operated under control of the sequence signal, extracts an upper limit frequency, average frequency and lower limit frequency of the transmitting signal by counting a clock of the transmitting signal at a designated time by the reference signal, and outputs the upper limit frequency, the average frequency and the lower limit frequency to the difference detection circuit, wherein the received frequency detector to which the reference signal, the sequence signal and the received signal are inputted is operated under control of the sequence signal, extracts an upper limit frequency, average frequency, lower limit frequency of the transmitting signal and a spread spectrum mode decision signal by counting a clock of the transmitting signal at a designated time by the reference signal, and outputs the upper limit frequency, the average frequency, the lower limit frequency and the spread spectrum mode decision signal to the difference detection circuit, and wherein the difference detection circuit to which the upper limit frequency, average frequency and lower limit frequency of the transmitting signal and the upper limit frequency, average frequency, lower limit frequency, and spread spectrum mode decision signal of the received signal are inputted outputs the frequency coordination signal and the spread spectrum selection signal based on those inputted signals.