Method for replacing defective memory cells in data processing apparatus

1. A method for replacing defective memory cells in a random access memory device of a data processing apparatus, the method which comprises:

providing the random access memory device with replacement memory cells, programmable connecting devices, and a control device for controlling replacing defective memory cells using the programmable connecting devices;

configuring the data processing apparatus to identify the defective memory cells in an operating state and to store addresses of the defective memory cells; and

in the operating state, actuating the control device with a control instruction for replacing the defective memory cells, and assigning the addresses of the defective memory cells to replacement memory cells such that the replacement memory cells replace the defective memory cells, and providing a code specific to the random access memory device for preventing inadvertent, erroneous, or unauthorized use of the control instruction, such that access to the control device is restricted by using a specific service mode.

2. The method according to claim 1 , which comprises: transmitting the code in at least three parts each including a mode identifier transmitted via control lines and an input mode transmitted via address lines.

3. The method according to claim 1 , which comprises: providing the random access memory device as a dynamic random access memory; and providing the replacement memory cells as static memory cells.

4. A configuration for replacing defective memory cells in a random access memory device, the configuration comprising:

a control device for evaluating a control instruction;

a plurality of programmable connecting devices;

a plurality of replacement memory cells;

a voltage source for generating a programming voltage required for programming said plurality of said programmable connecting devices; and

said control device for driving said voltage source and said plurality of said programmable connecting devices such that one of said plurality of said replacement memory cells is connected to an address of one of the defective memory cells, said control instruction having at least the address of the defective memory cells, an identifier specific to the replacement, and a code specific to the random access memory device for preventing inadvertent, erroneous or unauthorized use of the control instruction, such that access to the control device is restricted by using a specific service mode.

5. The configuration according to claim 4 , in combination with the random access memory device, wherein the random access memory device is a dynamic random access memory.