Memory device with error correction code module

1. A memory device, comprising:

a group of memory modules, each of the memory modules comprising a plurality of memory chips;

an external error correction code (ECC) module comprising at least one memory chip, wherein the external ECC module is configured to provide ECC functionality that is shared by the memory modules of the group; and

a memory controller configured to synchronously access the at least one memory chip of the external ECC module and memory chips of the memory modules of the group during a memory access cycle.

2. The memory device according to claim 1 , wherein the memory chips of the memory modules have substantially the same memory density as the at least one memory chip of the external ECC module.

3. The memory device according to claim 1 , wherein properties of the memory chips of the memory modules are substantially the same as properties of the at least one memory chip of the external ECC module.

4. The memory device according to claim 1 , wherein the memory chips of the memory modules and the at least one memory chip of the external ECC module have a “by eight” organization.

5. The memory device according to claim 1 , wherein each of the memory modules includes four ranks of memory chips.

6. The memory device according to claim 5 , wherein a first memory rank of each of the memory modules is connected to the memory controller by a point-to-point command/address (CA) bus connection.

7. The memory device according to claim 1 , wherein the group of memory modules includes two memory modules.

8. The memory device according to claim 1 , wherein the group of memory modules includes four memory modules.

9. The memory device according to claim 8 , wherein the memory modules have an electrical connector arrangement that is substantially the same as an electrical connector arrangement of the external ECC module.

10. The memory device according to claim 1 , wherein properties of the memory modules are substantially the same as properties of the external ECC module.

11. The memory device of claim 1 , wherein the group of memory modules comprises a first group of memory modules and the external ECC module comprises a first external ECC module, the memory device further comprising:

a second group of memory modules each comprising a plurality of memory chips; and

a second external ECC module comprising at least one memory chip, wherein the second external ECC module is configured to provide ECC functionality that is shared by the memory modules of the second group;

wherein the memory controller is coupled to the first and second external ECC modules via a common ECC channel, and the memory controller is configured to synchronously access the at least one memory chip of the second external ECC module and memory chips of the memory modules of the second group during a memory access cycle.

12. The memory device of claim 1 , wherein the memory chips of the memory modules are identical to the at least one memory chip of the external ECC module.

13. The memory device of claim 1 , wherein a relation of a memory density of the at least one memory chip of the external ECC module to a memory density of the memory chips of the memory modules depends on the number of memory modules to which the external ECC module is assigned to provide ECC functionality.

14. The memory device of claim 1 , wherein the memory controller simultaneously accesses the memory chips of the external ECC module and the memory modules in parallel.

15. The memory device of claim 1 , wherein the memory controller is connected to the ECC module via an ECC channel.

16. A memory device, comprising:

first and second groups of memory modules, each of the memory modules comprising a plurality of memory chips;

first and second external error correction code (ECC) modules respectively assigned to the first and second groups of memory modules, each of the external ECC modules comprising at least one memory chip that is substantially the same as the memory chips of the memory modules of the first and second groups, wherein the first external ECC module is configured to provide ECC functionality that is shared by the memory modules of the first group and the second external ECC module is configured to provide ECC functionality that is shared by the memory modules of the second group; and

a memory controller coupled to the memory modules of the first and second group via memory channels and coupled to the first and second external ECC modules via a common ECC channel, wherein the memory controller is configured to synchronously access the at least one memory chip of the first external ECC module and memory chips of the memory modules of the first group during a memory access cycle, and wherein the memory controller is configured to synchronously access the at least one memory chip of the second external ECC module and memory chips of the memory modules of the second group during a memory access cycle.

17. A method of operating a memory device, comprising:

assigning an external error correction code (ECC) module of the memory device to at least first and second memory modules of the memory device such that the external ECC module provides ECC functionality that is shared by the first and second memory modules, wherein the first and second memory modules and the external ECC module comprise memory chips;

synchronously performing a memory access to store bits in or retrieve bits from at least one memory chip of the external ECC module and memory chips of the first and second memory modules during a memory access cycle, wherein some of the bits accessed in the external ECC module are associated with bits accessed in the first memory module and others of the bits accessed in external ECC module are associated with bits accessed in the second memory module.

18. The method of claim 17 , wherein the memory chips of the external ECC module and the first and second memory modules are substantially identical, and a same number of bits are accessed in the at least one memory chip of the external ECC module as in individual memory chips of the first and second memory modules during the memory access cycle.

19. The method of claim 17 , wherein the memory chips of the external ECC module and the first and second memory modules are accessed simultaneously in parallel.

20. The method of claim 17 , wherein the memory access is a read operation.

21. The method of claim 17 , wherein the memory access is a write operation.

22. The method of claim 17 , further comprising:

accessing the at least one memory chip of the external ECC module through an ECC channel between the ECC module and a memory controller.