Mentor Graphics Corporation

Peer Schmitt

Charles W Selvidge

Philippe Diehl

Joshua Marantz

Cyril Quennesson

Charley Selvidge

Robert W Davis

A Random Access Memory (RAM) and method of using the same are disclosed. The RAM includes a plurality of memory cells arranged in columns and in rows with each memory cell coupled to at least one word line and at least one bit line. The RAM includes a plurality of switches with at least one of the switches coupled between two of the memory cells to allow data to be copied from one of the two memory cells to the other of the two memory cells. In another aspect, the two memory cells can be considered a dual bit cell that contains a copying mechanism. There are two interleaved memory planes, assembled from bit cells that contain two bits of information. One bit is the primary bit that corresponds to the normal RAM bit. The second bit is able to receive a copy and hold the primary value. When the copying mechanism is over, the two memory planes may act as two completely independent structures.

Random access memory for use in an emulation environment

A system and method are disclosed for communicating in a programmable core. The programmable core is within a single integrated circuit and is divided into multiple independent sub-cores. The sub-cores are coupled together using a multiplexer based network. In another aspect, the multiplexer-based network includes multiplexers associated with some of the sub-cores for sending data and demultiplexers associated with other sub-cores for receiving data. In yet another aspect, a clock is included in the multiplexer-based network for synchronizing communication between the multiplexers and demultiplexers.

Communication scheme between programmable sub-cores in an emulation environment

A system and method are disclosed to trace memory in a hardware emulator. In one aspect, a first Random Access Memory is used to store data associated with a user design during emulation. At any desired point in time, the contents of the first Random Access Memory are captured in a second Random Access Memory. After the capturing, the contents of the second Random Access Memory are copied to a visibility system. During the copying, the user design may modify the data in the first Random Access Memory while the captured contents within the second Random Access Memory remain unmodifiable so that the captured contents are not compromised. In another aspect, different size memories are in the emulator to emulate the user model. Larger memories have their ports monitored to reconstruct the contents of the memories, while smaller memories are captured in a snapshot RAM. Together the two different modes of tracing memory are used to provide visibility to the user of the entire user memory.

Memory tracing in an emulation environment

A system and method for compressing trace data from an emulation system. Scan chains may receive trace data from configurable logic blocks inside one or more emulation chips, and the data received from the scan chains may be compressed. Where delta compression is used, the scan chains may also perform a delta detection function. Alternatively, delta detection may be performed using the outputs of the scan chains. In addition, event detectors may be implemented within or outside of the scan chains. Compression of the trace data may include receiving a plurality of data sets and performing compression along cross-sections of the combined data sets.

Compression of emulation trace data

A memory device is disclosed having a plurality of dual-bit addressable memory cells. In each memory cell, a first storage circuit for storing a first bit may be activated or de-activated depending upon the state of a second bit stored in a second storage circuit. The second bit may be considered to be a 'don't care' bit, because depending upon the state of the second bit, the first bit may be irrelevant in that it cannot be read. Thus, each memory cell may effectively store three states: zero, one, and don't care.

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Paris, France

Peer Schmitt