Detecting circuit and detecting method of idle word for content addressable memory
AssigneeInternational Business Machines Corporation
InventorMasahiro Tanaka
Life of this patent
Estimating the term…
Abstract
In a CAM having valid cells, an idle word is detected and outputted by using the data in the valid cells and an address encoder. A detection circuit of an idle word for a content addressed memory having valid cells 15, which includes a unit 19 for supplying the output (valid 16) of the valid cell 15 to an address encoder 18 in response to an idle word detection signal IWD.
Claims9
A detecting circuit of an idle word during write, read or no-operation for a content addressed memory having valid cells, comprising a unit for supplying the output of a valid cell to an address encoder in response to an idle word detection signal, said unit includes a selecting circuit provided between a word match circuit and an address encoder, said selecting circuit switching and outputting the output of the valid cell and the output of the word match circuit to the address encoder in response to the idle word detection signal.
A content addressed memory (CAM) comprising:
- content addressable memory cells;
- valid cells;
- word match lines;
- a word match circuit;
- an address encoder, and
- a circuit for detecting an idle word during write, read or no-operation by using the output of a valid cell, said circuit includes a selecting circuit provided between the word match circuit and the address encoder, said selecting circuit switching and outputting the output of the valid cell and the output of the word match circuit to the address encoder in response to an idle word detection signal.
A detection method for detecting an idle word for a content addressed memory having valid cells during a write, read or no-operation, comprising the steps of:
- writing bit data representing the presence or absence of valid data to valid cells;
- and
- outputting the bit data of a valid cell to an address encoder in response to an idle word detection signal, which includes a step of switching and outputting the output of the valid cell and the output of a word match circuit to the address encoder in response to the idle word detection signal.
Dependencies are inferred from the claim text.