Quickturn Design Systems, Inc.

Quicktum Design Systems, Inc.

R Bryan Cook

William F Beausoleil

Tak-kwong Ng

Peter Tannenbaum

Helmut Roth

Lawrence A Thomas

Norton J Tomassetti

A system and method for determining which of several possible cable lengths has been used by reversing the end-to-end correspondence of at least two conductors in the cable. A different two conductors are selected to identify respective different cable lengths. Each input pin is connected to a correspondingly identified output pin, except for the pair with the outputs reversed, which pair signifies the cable length.

High speed software driven emulator comprised of a plurality of emulation processors with improved board-to-board interconnection cable length identification system

A software driven emulator in which the stored emulation program for a processor module is compiled to include a code bit or bits in the emulation instruction step sequence that is decoded as main data memory disable command. Thus, once in each emulation program cycle, the memory controller disables the main data memories on the module, and allows the maintenance bus to read or write data to these memories.

High speed software driven emulator comprised of a plurality of emulation processors with a method to allow memory read/writes without interrupting the emulation

In an emulator processor cluster, the read ports of a shared input and data memory stack are time multiplexed to serve more than one processor. In an exemplary embodiment of the invention, a 256&#xd7;8 memory array serves as the shared memory for four processors in a cluster. Two read ports are time multiplexed among the four processors in the cluster. On one read cycle, data from the two read ports is coupled to two processors. The next read cycle reads data from the same two ports to the remaining two processors. In the preferred embodiment, the memory operates at twice the system clock speed so that overall emulation process execution time is not effected.

High speed software driven emulator comprised of a plurality of emulation processors with improved multiplexed data memory

A system and method for bulk transfer to and from the SRAMs in which a starting memory address is latched and is then incremented every clock cycle to generate a new memory address. The addresses are decoded and memory requests are pipelined to the SRAM memory, one every clock cycle. When the memory controller detects transfer of the boundary of a predetermined number of clock cycles or words (e.g. 64 words or four clock cycles) the burst mode of data transfer is stopped and the memory controller waits for a 'done' signal before resuming another cycle of the burst transfer mode. The memory controller on detecting a request on this address boundary first does a memory refresh followed by a requested operation; e.g. a continuation of the transfer operation.

High speed software driven emulator comprised of a plurality of emulation processors with a method to allow high speed bulk read/write operation synchronous DRAM while refreshing the memory

A software driven emulator has a maintenance bus operating protocol mode in which, after an initial address phase, data is streamed continuously by automatically incrementing the sending and receiving addresses.

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Poughkeepsie, NY, United States of America

R Bryan Cook