Memory apparatus and semiconductor system including the same

1. A memory apparatus comprising:

an address decoding circuit configured to output a test redundancy address based on an address that is transmitted from a memory controller; and

a redundancy address check circuit configured to determine whether the test redundancy address is replacing a failed address by comparing the test redundancy address with a reference address, in an ECC test operation,

wherein the reference address is a redundancy address that was most recently used to replace a failed address.

2. The memory apparatus according to claim 1 , wherein the redundancy address check circuit further compares the test redundancy address with a last redundancy address, among a plurality of redundancy addresses, in order to determine whether the test redundancy address is replacing a failed address.

3. The memory apparatus according to claim 1 , further comprising an address selection circuit,

wherein the address decoding circuit further outputs an internal address along with the test redundancy address based on the address,

wherein the redundancy address check circuit outputs a redundancy select signal to the address selection circuit by determining whether the test redundancy address is replacing a failed address, and

wherein the address selection circuit outputs any one of the internal address and the test redundancy address in response to the redundancy select signal.

4. The memory apparatus according to claim 3 , wherein the redundancy address check circuit enables the redundancy select signal when it is determined that the test redundancy address is not replacing a failed address, and

wherein the address selection circuit outputs the test redundancy address of the internal address and the test redundancy address when the redundancy select signal is enabled.

5. The memory apparatus according to claim 3 , wherein the redundancy address check circuit disables the redundancy select signal when it is determined that the test redundancy address is replacing a failed address, and

wherein the address selection circuit outputs the internal address of the internal address and the test redundancy address when the redundancy select signal is disabled.

6. The memory apparatus according to claim 3 , wherein the redundancy address check circuit disables the redundancy select signal while the ECC test operation is not being performed, and

wherein the address selection circuit outputs the internal address of the internal address and the test redundancy address when the redundancy select signal is disabled.

7. The memory apparatus according to claim 3 , wherein the address decoding circuit outputs a redundancy address that replaces the address as the internal address when the address is a failed address and outputs the address as the internal address when the address is a normal address.

8. The memory apparatus according to claim 3 , further comprising a read/write circuit configured to, when the address selection circuit outputs the test redundancy address, store data in a redundancy region that corresponds to the test redundancy address to perform the ECC test operation.

9. The memory apparatus according to claim 1 , wherein the redundancy address check circuit outputs a warning signal to be transmitted to the memory controller when it is determined that the test redundancy address is replacing a failed address.

10. The memory apparatus according to claim 9 , further comprising a write driver circuit configured to drive data that is transmitted from the memory controller,

wherein the write driver circuit does not drive the data in response to the warning signal.