Technology for supressing noise of data bus circuit
AssigneeFujitsu Limited
InventorsHideyuki Iida, Yoshiro Tanaka, Keisuke Nakamura, Yosuke Konaka, Takayuki Niiyama, Daisuke Seki
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Abstract
A data bus circuit connects a south bridge driven by a first voltage and a bay driven by a second voltage. The first voltage and the second voltage are different. The data bus circuit includes a data bus that electrically connects the south bridge and the bay, and a Thevenin termination circuit that is arranged on the data bus at a point. The Thevenin termination circuit maintains a voltage at the point substantially equal to the first voltage.
Claims4
A data bus circuit that connects a first device driven by a first voltage and a second device driven by a second voltage, wherein the first voltage and the second voltage are different, comprising:
- a data bus that electrically connects the first device and the second device;
- a Thevenin termination circuit that is arranged on the data bus at a point that is anywhere between the first device and the second device, wherein the Thevenin termination circuit has a configuration so that a voltage at the point is substantially equal to the first voltage;
- and
- a bypass condenser that is connected in parallel with the Thevenin termination circuit between the high voltage terminal and the low voltage terminal, wherein
- the Thevenin termination circuit includes a first resistance provided between the point and a high voltage terminal and a second resistance provided between the point and a low voltage terminal, wherein
- resistances of the first resistance and the second resistance are determined based on a ratio of the first voltage and the second voltage so that the voltage at the point is substantially equal to the first voltage, wherein
- the data bus includes a plurality of signal lines, and the Thevenin termination circuit and the bypass condenser are provided corresponding to at least one of the signal lines, wherein
- the data bus includes 16 signal lines, and the Thevenin termination circuit and the bypass condenser are provided corresponding to 8 signal lines.
Dependencies are inferred from the claim text.