US 11,955,202 B2
Multilevel content addressable memory, multilevel coding method of and multilevel searching method
Ming-Hsiu Lee, Hsinchua (TW); and Po-Hao Tseng, Taichung (TW)
Assigned to MACRONIX INTERNATIONAL CO., LTD., Hsinchu (TW)
Filed by MACRONIX INTERNATIONAL CO., LTD., Hsinchu (TW)
Filed on Nov. 16, 2022, as Appl. No. 18/055,855.
Application 18/055,855 is a division of application No. 17/383,562, filed on Jul. 23, 2021, granted, now 11,532,337.
Prior Publication US 2023/0075257 A1, Mar. 9, 2023
Int. Cl. G11C 15/00 (2006.01); G11C 7/10 (2006.01); G11C 15/04 (2006.01)
CPC G11C 7/1063 (2013.01) [G11C 7/1069 (2013.01); G11C 7/109 (2013.01); G11C 7/1096 (2013.01); G11C 15/04 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A multilevel searching method for a multilevel content addressable memory (MCAM), comprising:
storing a plurality of stored words in a plurality of NAND strings;
inputting an input search word to the NAND string, wherein each of the stored words and the input search word is converted from a multilevel-bit binary data into a digital string data, if a decimal value of the multilevel-bit binary data is an exact value, a number of an indicating bit in the digital string data is the exact value, a length of the digital string data is equal to or larger than a highest decimal value of the multilevel-bit binary data; and
outputting a comparison result, wherein if the digital string data of the input search word overlap the digital string data of one of the stored words, the comparison result is a match signal.