A memory device is provided. The memory device includes a bit cell having a first invertor connected between a first node and a second node and a second invertor connected between the first node and the second node. The first invertor and the second invertor are cross coupled at a first data node and a second data node. The memory device further includes a pull down circuit connected to the second node. The pull down circuit is operative to pull down a voltage of the second node below a ground voltage in response to an enable signal.

Systems, devices, circuits, methods, and non-transitory computer readable media that enable storing and searching arbitrary segments of ranges of analog values are disclosed. Various analog content addressable memory (aCAM) circuit implementations having the capability to store and search outside of a range of values, within any of multiple disjoint ranges, or outside of multiple ranges are disclosed. The disclosed aCAM circuit implementations make searching for complex input features more flexible and efficient, thereby yielding a technological improvement over conventional solutions. In some implementations, an aCAM may include multiple pull-down transistors connected in series to a match line that is pre-charged, in which case, the aCAM detects a match if the match line is not discharged by the pull-down transistors, which occurs if at least one pull-down transistor is in an OFF state. In other implementations, an aCAM includes pass gates connected to a match line to detect a match.

A memory system includes a memory device comprising a value data block a content addressable memory (CAM) block storing a plurality of stored search keys. The memory system further includes a processing device that receives an input search key, identifies, from the plurality of stored search keys in a CAM block of a memory device, multiple redundant copies of a stored search key that match the input search key, and determines a plurality of locations in a value data block, the plurality of locations corresponding to the multiple redundant copies, wherein one of the plurality of locations comprises a first timestamp and data representing a value associated with the input search key, and wherein a remainder of the plurality of locations comprises one or more additional timestamps. The processing device further determines whether the first timestamp matches the one or more additional timestamps, and responsive to the first timestamp matching the one or more additional timestamps, retries from the one of the plurality of locations, the data representing the value associated with the input search key.

A memory system includes a memory device comprising a value data block a content addressable memory (CAM) block storing a plurality of stored search keys. The memory system further includes a processing device that receives an input search key, identifies, from the plurality of stored search keys in a CAM block of a memory device, multiple redundant copies of a stored search key that match the input search key, and determines a plurality of locations in a value data block, the plurality of locations corresponding to the multiple redundant copies, wherein one of the plurality of locations comprises a first timestamp and data representing a value associated with the input search key, and wherein a remainder of the plurality of locations comprises one or more additional timestamps. The processing device further determines whether the first timestamp matches the one or more additional timestamps, and responsive to the first timestamp matching the one or more additional timestamps, retries from the one of the plurality of locations, the data representing the value associated with the input search key.

An analog CAM and an operation method thereof are provided. The analog CAM includes a matching line, an analog CAM cell and a sense amplifier. Each of the at least one analog CAM includes a first floating gate device having a N type channel and a second floating gate device having a P type channel. A match range is set through programming the first floating gate device and the second floating gate device. The sense amplifier is connected to the matching line. If an inputting signal is within the match range, a voltage of the matching line is pulled down to be equal to or lower than a predetermined level. The sense amplifier outputs a match result if the voltage of the matching line is pulled down to a predetermined level.

An analog CAM and an operation method thereof are provided. The analog CAM includes a matching line, an analog CAM cell and a sense amplifier. Each of the at least one analog CAM includes a first floating gate device having a N type channel and a second floating gate device having a P type channel. A match range is set through programming the first floating gate device and the second floating gate device. The sense amplifier is connected to the matching line. If an inputting signal is within the match range, a voltage of the matching line is pulled down to be equal to or lower than a predetermined level. The sense amplifier outputs a match result if the voltage of the matching line is pulled down to a predetermined level.

A content-address memory (CAM) and an operation method are provided. The content-address memory comprises: a plurality of first signal lines; a plurality of second signal lines; and a plurality of CAM memory cells coupled to the first signal lines and the second signal lines, wherein in data match, a plurality of input signals are input into the CAM memory cells via the first signal lines; the input signals are compared with contents stored in the CAM memory cells; and a match result is determined based on an electrical characteristic of the second signal lines.

A content-address memory (CAM) and an operation method are provided. The content-address memory comprises: a plurality of first signal lines; a plurality of second signal lines; and a plurality of CAM memory cells coupled to the first signal lines and the second signal lines, wherein in data match, a plurality of input signals are input into the CAM memory cells via the first signal lines; the input signals are compared with contents stored in the CAM memory cells; and a match result is determined based on an electrical characteristic of the second signal lines.

A TCAM comprises a plurality of first search lines, a plurality of second search lines, a plurality of memory cell strings and one or more current sensing units. The memory cell strings comprise a plurality of memory cells. Each of the memory cells is coupled to one of the first search lines and one of the second search lines. The current sensing units, coupled to the memory cell strings. In a search operation, a determination that whether any of the data stored in the memory cell strings matches a data string to be searched is made according to whether the one or more current sensing units detect current from the memory cell strings, or according to the magnitude of the current flowing out from the memory cell strings detected by the one or more current sensing units.

A TCAM comprises a plurality of first search lines, a plurality of second search lines, a plurality of memory cell strings and one or more current sensing units. The memory cell strings comprise a plurality of memory cells. Each of the memory cells is coupled to one of the first search lines and one of the second search lines. The current sensing units, coupled to the memory cell strings. In a search operation, a determination that whether any of the data stored in the memory cell strings matches a data string to be searched is made according to whether the one or more current sensing units detect current from the memory cell strings, or according to the magnitude of the current flowing out from the memory cell strings detected by the one or more current sensing units.