Apparatus and method for providing dynamically assigned switch paths

An information switch, comprising:

• a first CAM;
• a RAM;
• a second CAM, portions of the first CAM, RAM and second CAM being associated to form a means for storing a word;
• means associated with said first and second CAM portions for storing addresses for words, said first CAM portions storing addresses of information sources and said second CAM portions storing addresses of information destinations;
• means for addressing said first CAM with an address;
• means for addressing said second CAM with an address;
• means for writing to and reading from the RAM including means for connecting the RAM to information sources and destinations, whereby each word storing means is capable of establishing a path between an information source and an information destination, said paths being established by addressing the first CAM with a source address to access the RAM portion of a word storing means containing the source address, connecting the RAM to the addressed source, writing information from the addressed source into the RAM portion of the word storing means containing the source address while the RAM portion is accessed, addressing the second CAM with a destination address to access the RAM portion of a word storing means containing the destination address, reading information from the RAM portion of the word storing means that is addressed while the RAM portion is accessed and connecting the RAM portion to addressed destination to provide the information to the destination.

A switch for providing paths between a plurality of sources and destinations, comprising:

• a memory array having a plurality of word storage means, each word storage means, including a first CAM portion, a RAM portion and a second CAM portion;
• means for addressing the first CAM portions;
• means for addressing the second CAM portions;
• and
• means for writing to and reading from the RAM portion, whereby addresses of sources may be stored in the first CAM portions, and addresses of destinations may be stored in the second CAM portions so that the first CAM portions may be addressed with a source address to gain access to the word and enable its RAM portion allowing information from a source to be written into the RAM portion which information may be read from the RAM portion by subsequently addressing the second CAM portions with the destination address to gain access to the word and enable the RAM to be read to the destination.

A method of switching data from a source to a destination using a memory array of the type that has a first CAM, a RAM and a second CAM, portions of the first CAM, RAM and second CAM being associated to form a means for storing a word with the CAM portions of each word storing means storing addresses for the word so that the RAM portion of any word storing means may be accessed using addresses stored in the CAM portions, said method comprising the steps of:

• storing a source address in the first CAM portion of a word storing means;
• storing a destination address in the second CAM portion of a word storing means;
• accessing the RAM portion of the word storing means by addressing the first CAM portion of the word storing means with a source address;
• while accessing the RAM portion of the word storing means writing in said RAM portion data appearing at the addressed source;
• addressing the second CAM portion of the word storing means with a destination address thereby accessing the RAM portion of the addressed word storing means;
• and
• reading the data in the RAM portion to the addressed destination.