GENERAL DESCRIPTION

The MU9C4320L ATMCAM is a 4K x 32 Content Addressable Memory (CAM) with a 32-bit wide data interface. The device is designed for use in ATM switches and routers to provide very high throughput VPI/VCI translation through lookup tables held in external RAM. VPI/VCI fields from the ATM cell header are compared against a list of current connections stored in the CAM array. As a result of the comparison, the ATMCAM generates an address that is used to access an external RAM where VPI/VCI mapping data and other information associated with the connection are stored.

DISTINCTIVE CHARACTERISTICS

• 4096 x 32-bit Content Addressable Memory (CAM)

• 70 ns compare and output time per VPI/VCI

• 32-bit Data I/O port

• 16-bit Match Address Output port directly addresses external RAM containing associated data of any width

• Address/Control bus directly controls CAM operations for faster throughput

• Instruction and Status registers for optional software control

• Simultaneously compares Virtual Paths and Virtual Channels

• Cascadable for increased depth

• Extensive set of control states for flexibility

• JTAG interface

• 100-pin TQFP package; 3.3 volt operation

APPLICATION BENEFITS

• High performance VPI/VCI translation for ATM switches and routers, up to OC-48

• Fully deterministic translation, independent from the size of the list and the length of VPI/VCI

• Pipelined architecture for increased throughput

• No limitation of the range of legal values for VPI/VCI, guaranteeing full interoperability

• Cell tagging can be performed without any time penalty

• Easy buffer management in “Find and Replace” mode because of the ability to check CLP field during VPI/VCI translation

• No limitation in the amount of associated information stored with each connection

• No time penalty when checking both VPI/VCI and VPI only connections