Quickturn Design Systems, Inc.

John E Chilton

Tony R Sarno

Ingo Schaefer

Mark S Papamarcos

Curt Blanding

Michael C Tsou

Bernard Y Chan

A logic analysis subsystem in a time-sliced emulator. The logic analysis subsystem 'reconstructs' signals that were previously reduced by the compiler and allows the user to set breakpoints and triggers using these and other signals of the emulated circuit. The present invention includes a 'logic analysis subsystem compiler' and 'logic analysis subsystem hardware.' The logic analysis subsystem compiler is either a subpart of the regular emulator compiler or is a standalone compiler. It compiles the design to be emulated and generates control instructions for the logic analysis subsystem hardware. The logic analysis subsystem hardware is incorporated into the time-sliced emulator to receive signals generated by the emulator during emulation. When the logic analysis subsystem operates, the control instructions cause the logic analysis subsystem to reconstruct previously reduced signals received from the emulator. These signals (along with the signals received from the emulator) may be used by the user to set breakpoints and triggers in the logic analysis subsystem.

Logic analysis subsystem in a time-sliced emulator

A time-sliced hardware-based emulator including at least one of: programmable I/O assignment; programmable levels of DC voltage; programmable pull-up or pull-down resistors in the emulator on a pin-by pin basis; programmable forcing and/or disabling of value output from the emulator on each pin; programmable clocking; and programmable sample modes. An emulator is connected to a target system via a Pod System Interface (PSI), a specially designed cable, and a Pod User Interface (PUI). For data traveling from the emulator to the target system, each PSI receives up to 128 bits of data from the emulator. The cable, however, is only 32 bits wide. Therefore, the emulator multiplexes the data sent over the cable, sending eight interleaved groups of 32 bits to the PSI in accordance with a fast clock signal. Each PUI receives the groups of 32 bits from the PSI and sends them to the target system in accordance with control signals from the emulator. For data traveling from the target system to the emulator, each PUI receives up to 128 bits of data from the target system. Each PUI sends four groups of 32 bits in accordance with a fast clock signal. Each PSI receives the groups of 32 bits and holds them in an internal register, sending the received bits to the emulator under control of the emulator.

Software reconfigurable target I/O in a circuit emulation system

A logic emulation system for emulating the operation of a circuit. A uniform routing architecture is provided where a first set of selectors (multiplexers) is coupled to a set of shift registers that are in turn coupled to a second set of selectors. The outputs of the second set of selectors are coupled to the inputs of the logic processors. The arrangement of first selectors coupled to shift registers coupled to second selectors coupled to logic processors ensures that uniform routing exists among all of the logic processors in the emulation system. This, in turn, provides a flat programming model so that compilation steps including technology mapping and scheduling are independent of each other, resulting in faster compile times.

Emulation system having multiple emulated clock cycles per emulator

A method and apparatus for outputting a current state of a real-time circuit emulator. When the emulator is set to a predetermined state, it checkpoints the contents of certain memory and registers at the time it enters the predetermined state. The output of the emulator can be used as input to the emulator or as input to another system, such as a simulator, which does not operate in real-time. If the simulator also generates an output having same format, the output of the simulator can also be input to the real-time emulator.

Checkpointing in an emulation system

A system and method for emulating memory designs is described. The system includes a time sliced logic emulator. The time sliced logic emulator emulates the functions performed in one cycle of a target design by emulating portions of the functions in a set of time slices. That is, a set of time slices represents a single clock cycle in the target design. The system emulates many different types of memory designs included in the target design. The system includes an emulation memory. The memory designs are mapped to the emulation memory via a programmable address generation block. For a given time slice, the programmable address generation block generates an address that maps all or part of a memory design address to an emulation memory address. The programmable address generation block allows multiple memory designs to be mapped to a single emulation memory and allows a single memory design to be mapped to multiple emulation memories. Thus, over multiple time slices, the system can emulate many different types of memories.

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Soquel, CA, United States of America

John E Chilton