摘要:
Methods for determining induced noise on a given victim by a set of aggressor signals are presented, and for identifying the worst case aggressor switching time alignment that causes the worst case victim noise. The method removes circuit analysis pessimism related to simultaneous switching noise (SSN) in a circuit design tool by determining physically impossible combinations of victim-aggressor input/output (I/O) pins in a circuit design and culling out the impossible combinations from the list of possible victim-aggressor combinations. The method further performs a switching window SSN analysis of the circuit design with a common uncertainty removal algorithm taking into consideration the list of possible victim-aggressor combinations, and determines the maximum voltage noise induced on I/O pins of the circuit design. The results of the noise analysis are displayed to the user.
摘要:
This invention provides methods, computer program products, and systems to guide a user in optimizing the Simultaneous Switching Noise (SSN) of an electronic device by using visual approaches on a graphical user interface (GUI). Also provided is an interactive feedback mechanism that enables the user to evaluate the effectiveness of an optimization method. A matrix representation of the different I/O pins on the device shows the level of SSN at different victim pins caused by switching aggressor pins. The SSN is depicted using different graphical representations. Associated with the SSN of each victim pin is the graphical representation of its accuracy. The accuracy rating denotes the reliability of the SSN and is an indication of how sensitive a victim pin is to errors. In the interactive feedback mechanism, user input on SSN optimization is received and used to calculate the new SSN and accuracy rating of different victim pins on the device. The new data is then updated in a timely manner on the GUI.
摘要:
Extended linear superposition methods, computer program products and systems to calculate Simultaneous Switching Noise (SSN) on victim Input/Output (I/O) pins of an electronic component caused by aggressor I/O pins is provided. A method includes calculating the quiet output voltage on a victim pin caused by the power supply only, and then calculating an aggressor noise response induced on the victim pin caused by a single aggressor pin and the power supply. To calculate SSN for a combination of aggressors, the SSNs for the different aggressors are linearly combined, and then the effects of the power supply are discounted by using the calculated quiet output voltage. Additionally, a linear victim substitution model is introduced to replace a full buffer model for a victim pin with a resistor with different resistance values depending on the induced voltage. Further, an alternate transmission line model is introduced to simplify SSN simulations of transmission lines.
摘要:
Circuitry for facilitating the use of the memory elements in the look-up tables (“LUTs”) of a field programmable gate array (“FPGA”) as user-accessible, distributed RAM. For example, a register associated with a LUT and that is not needed in the read data path in user RAM mode can be used to register data for writing in user RAM mode. As another example, an otherwise unneeded register associated with a LUT can be used to provide a synchronous read address signal for user RAM mode. Several other features are shown for similarly facilitating user RAM mode with minimal (if any) additional circuitry being required in the FPGA.
摘要:
An embodiment of the present invention provides a programmable logic device (“PLD”) including a redundancy architecture adapted to selective route signals via first or second staggered vertical lines. Other embodiments provide configuration logic and programs for determining routing selections. Other embodiments provide proximate grouping of vertical lines driven from a same row. Other embodiments provide definition of spare row locations once defective row locations are known.
摘要:
Circuitry for facilitating the use of the memory elements in the look-up tables (“LUTs”) of a field programmable gate array (“FPGA”) as user-accessible, distributed RAM. For example, a register associated with a LUT and that is not needed in the read data path in user RAM mode can be used to register data for writing in user RAM mode. As another example, an otherwise unneeded register associated with a LUT can be used to provide a synchronous read address signal for user RAM mode. Several other features are shown for similarly facilitating user RAM mode with minimal (if any) additional circuitry being required in the FPGA.
摘要:
A programmable logic device (PLD) includes first and second circuits. The first and second circuits are part of a user's design to be implemented using the PLD's resources. The first circuit is powered by a first supply voltage. The second circuit is powered by a second supply voltage. At least one of the first and second supply voltages is determined by a PLD computer-aided design (CAD) flow used to implement the user's design in the PLD.
摘要:
The present invention provides techniques for compressing and decompressing data in a programmable circuit. Programmable circuits can be configured according to user design by configuration data. Configuration data is compressed using a compression algorithm to save memory space. When the configuration data is needed, the compressed configuration data is decompressed using a decompressor. A decompressor can decompress configuration data using a variety of decompression algorithms such as arithmetic decoding. In an arithmetic encoding algorithm, symbol probabilities are used to increase compression of the data. The symbol probabilities can be transferred in a header of the encoded data stream and subsequently stored in a symbol probability table. The input of the decompressor may be coupled to a FIFO that temporarily stores the encoded data until it can be used by the decompressor.
摘要:
In accordance with one aspect of the invention, a hole is formed within an LE array of a PLD by interrupting the LE array base signal routing architecture such that a hole is left for IP function block to be incorporated. An interface region is provided for interfacing the remaining LE array base signal routing architecture to the IP function block.
摘要:
In accordance with one aspect of the invention, a hole is formed within an LE array of a PLD by interrupting the LE array base signal routing architecture such that a hole is left for IP function block to be incorporated. An interface region is provided for interfacing the remaining LE array base signal routing architecture to the IP function block.