Systems having modules with selectable on die terminations

A system comprising:

• first and second modules;
• a circuit board including first and second module connectors to receive the first and second modules, respectively;
• a first path of conductors extending from the circuit board to the first module connector, to the first module, back to the first module connector, to the circuit board, to the second module connector, to the second module, and to on module terminations of the second module, wherein the first path in the first module is connected to stubs wich in turn are coupled to stubs of first and second chips of the first module;
• and
• a second path of conductors extending from the circuit board to the second module connector, to the second module, back to the second module connector, to the circuit board, to the first module connector, to the first module, and to on module terminations of the first module, wherein the second path in the second module is connected to stubs which in turn are coupled to stubs of first and second chips of the second module.

A DRAM comprising:

• a stub to pass data;
• a load;
• and
• selectable on die termination coupled to the stub and load, wherein the on die termination includes multiple field effect transistors that can be individually turned on or off to create a desired termination impendance and the DRAM further comprises a linearized active resistive termination bias circuit coupled to control inputs for at least some of the field effect transistors.