Adapter card for connection to a data bus in a data processing unit and method for operating a DDR memory module

A method for operating a DDR memory module connected through an adapter card to a data bus of a data processing unit, comprising:

• disconnecting the DDR memory module from the data bus, wherein a switching device disposed in the adapter card switches-off connection between a first card interface of the adapter card which externally connects to the DDR memory module and a second card interface of the adapter card which externally connects to the data bus;
• connecting the DDR memory module to a memory unit of the adapter card having test mode data stored therein;
• transmitting the test mode data to the DDR memory module to call up a test mode in the DDR memory module;
• and
• activating a test mode of the DDR memory module.

An adapter comprising:

• a first card interface means for connecting to an external Double Data Rate (DDR) memory module;
• a second card interface means for connecting to a data bus of an external data processing unit;
• a storage means for storing test mode data;
• a switching means for switching between a first and second switching state, wherein, in the first switching state, the data bus is connected, via the second card interface means, to the first card interface means and, in a second switching state, the first card interface means is decoupled from the data bus and connected to the storage means;
• and
• a control means for controlling the switching means between the first and second switching states.