Semiconductor integrated circuit and semiconductor integrated circuit system having serially interconnectable data buses

A semiconductor integrated circuit connected to multiple data bus pairs, each said data bus pair being terminated with a resistor,

• wherein the circuit comprises means for selecting a changeable current path between first and second power supplies through the data bus pairs, and
• wherein the changeable path selecting means includes:
• a first current source connected to the first power supply;
• a second current source connected to the second power supply;
• first and second switching devices, which are connected to the first current source and selectively supply current to one of the data bus pairs;
• third and fourth switching devices, which are connected to the second current source and selectively extract the current from another one of the data bus pairs;
• and
• a fifth switching device for interconnecting the data bus pairs together.

A semiconductor integrated circuit connected to multiple data bus pairs, each said data bus pair being terminated with a resistor, each said data bus pair having a first data line and a second data line;

• wherein the circuit comprises means for selecting a changeable current path between first and second power supplies through the data bus pairs, and
• wherein the changeable path selecting means includes:
• a first current source, which is connected to the first power supply and supplies current to a first data bus pair of the data bus pairs;
• a second current source, which is connected to the second power supply and extracts the current from a second data bus pair of the data bus pairs;
• and
• first, second, third and fourth switching devices,
• the first switching device being connected to the second data line of the first data bus pair and to the first data line of the second data bus pair;
• the second switching device being connected to the first data line of the first data bus pair and to the first data line of the second data bus pair;
• the third switching device being connected to the second data line of the first data bus pair and to the second data line of the second data bus pair;
• and
• the fourth switching device being connected to the first data line of the first data bus pair and to the second data line of the second data bus pair.

A semiconductor integrated circuit system comprising:

• first and second integrated circuit chips,
• a plurality of complementary data buses, each said bus being terminated with a resistor, said system exchanging data between the first integrated circuit chip and the second integrated circuit chip through the complementary data buses, and
• a driver with a current drive capability for driving the complementary data buses,
• wherein a current being utilized to drive a first complementary data bus of said plurality of complementary data buses is also utilized to drive a second complementary data bus of said plurality of complementary data buses.