Apparatus and method for topography dependent signaling

A method in a bus system of adjusting a transmission parameter of a transmitter located on a first module of a plurality of modules in the bus system, comprising:

• determining a position of the first module within the bus system;
• determining a control value based upon the position of the first module;
• conveying the control value to the transmitter;
• and
• adjusting the transmission parameter of the transmitter using the control value.

A signal transmission bus system, comprising:

• a port for receiving bus system topography information;
• a register coupled to the port, the register storing the bus system topography information;
• parameter adjustment circuitry coupled to the register adjusting a parameter control signal in accordance with the bus system topography information;
• and
• an output driver for driving an output signal onto a bus within the bus system, the output driver setting a transmission parameter of the output signal in accordance with the parameter control signal.

Apparatus for adjusting a slew rate of an output signal generated by a transmitter, comprising:

• a port for receiving position dependent information associated with the transmitter;
• a register for storing the position dependent information;
• slew rate control circuitry coupled to the register for adjusting a slew rate control signal in accordance with the position dependent information;
• and
• output circuitry for driving the output signal onto a bus coupling the transmitter to a receiver, the output driver setting the slew of the output signal in accordance with the slew rate control signal.

Apparatus for adjusting an output current of an output signal generated by a transmitter, comprising:

• a port for receiving position dependent information associated with the transmitter;
• a register for storing the position dependent information;
• current control circuitry coupled to the register for adjusting a current control signal in accordance with the position dependent information;
• and
• output circuitry for driving the output signal onto a bus coupling the transmitter to a receiver, the output driver setting a magnitude of the current of the output signal in accordance with the current control signal.

A system with adjustable signal characteristics, comprising:

• a bus;
• a controller coupled to the bus for determining a topography dependent parameter associated with a particular transmitter and for transmitting the topography dependent parameter to the particular transmitter;
• a plurality of modules coupled to the bus, each module including:
• a topography indicating circuit coupled to the controller via the bus, the topography indicating circuit indicating a topography of each transmitter on the bus;
• and
• a plurality of devices, each device including a bus transmitter for transmitting data to the controller via the bus;
• each bus transmitter including:
• a first port for receiving a first topography dependent parameter;
• a first register coupled to the port, the first register storing the first topography dependent parameter;
• a first parameter adjustment circuit coupled to the first register adjusting a first parameter control signal in accordance with the first topography dependent parameter;
• and
• an output driver for driving a first data signal onto the bus, the output driver setting a transmission parameter of the first data signal in accordance with the first parameter control signal.

A method in a bus system of adjusting a parameter of a bus receiver in the bus system, comprising:

• determining a topography of the bus system;
• determining a control value based upon the topography;
• conveying the control value to the bus receiver;
• and
• receiving an input signal from a bus coupling the bus receiver to a transmitter, and generating a first signal from the input signal, including adjusting a parameter of the first signal in accordance with the control signal.

A method in a bus system of adjusting a receive data parameter of a bus receiver located on a first module of a plurality of modules in the bus system, comprising:

• determining a position of the first module within the bus system;
• determining a control value based upon the position of the first module;
• conveying the control value to the bus receiver;
• and
• adjusting the receive data parameter of the bus receiver using the control value.

A signal transmission bus system, comprising:

• a port for receiving bus system topography information;
• a register coupled to the port, the register storing the bus system topography information;
• parameter adjustment circuitry coupled to the register adjusting a parameter control signal in accordance with the bus system topography information;
• and
• a bus receiver receiving an input signal from a bus coupling the bus receiver to a transmitter, the bus receiver generating a first signal from the input signal, including adjustment circuitry for adjusting a parameter of the first signal in accordance with the parameter control signal.