Table lookup apparatus using content-addressable memory based device and related table lookup method thereof

A table lookup apparatus, comprising:

• a content-addressable memory (CAM) based device, having a plurality of main CAM entries and at least a redundant CAM entry;
• and
• a control logic, configured to program the redundant CAM entry by a data word to serve as a new main CAM entry, utilize the new main entry as replacement of a specific main CAM entry in the CAM based device, and program the specific main CAM entry by the data word.

A table lookup method, comprising:

• vertically storing a plurality of tables in content-addressable memory (CAM) entries of a CAM based device in a word-wise aggression fashion, wherein the CAM entries are responsive to a valid bit input including valid bits of the CAM entries, and a CAM entry is valid when receiving a corresponding valid bit set by a first logic value and is invalid when receiving the corresponding valid bit set by a second logic value;
• and
• masking a portion of the valid bit input by assigning the second logic value to each valid bit included in the portion of the valid bit input, wherein the portion of the valid bit input corresponds to non-selected table(s).