Data processing system with master and slave devices and asymmetric signal swing bus

A data processing system comprising:

• a bus, wherein said bus comprises a plurality of bus lines for carrying bi-directional multiplexed address, data and control information;
• a plurality of slave devices coupled in parallel to said bus, each of said slave devices having a slave bus transceiver for transmitting and receiving signals on said bus;
• and
• a master device coupled in parallel to said bus, said master device having a master bus transceiver for transmitting and receiving signals on said bus, wherein signals transmitted from said slave bus transceivers to said master bus transceiver vary over a smaller voltage range than signals transmitted from said master bus transceiver to said slave bus transceivers.

A method of processing data in a system comprising a bus, a plurality of slave devices and a master device, said method comprising the steps of:

• transmitting signals from said slave devices to said master device on said bus, wherein the voltage on said bus varies within a first range as said signals are transmitted from said slave devices to said master device;
• transmitting signals from said master device to said slave device on said bus, wherein the voltage on said bus varies within a second range as said signals are transmitted from said master device to said slave devices, wherein said second range is larger than said first range;
• and
• providing said data processing system with a first supply voltage and a second supply voltage, wherein said first range is less than the difference between said first and second supply voltages and said second range is approximately equal to the difference between said first and second supply voltages.