This application claims priority of and the benefit of Taiwan Application No. 107138489, filed Oct. 31, 2018.
The present disclosure relates to a simulation system and method.
As the complexity of chip system design increases, the product development time required for a traditional Register-Transfer Level (RTL) design process is getting longer. Current chip system designs require a high degree of integration of hardware and software, so that the time for software development is essential to whole product development cycle. However, the traditional RTL design process cannot provide a software simulation environment in the early stages of hardware design. Therefore, it is an inevitable trend to shorten the development time of system software and hardware by using Electronic System-Level (ESL) design.
Most of the current practice-level technologies can simulate performance and power consumption, and a few techniques can simulate temperature, but no techniques have been found that can simulate electrical properties. On the one hand, electrical-simulation engineering continues to pursue high-frequency models and accuracy, but it has never thought of sacrificing accuracy in exchange for accelerated simulation effects. On the other hand, the system-level simulation technology of heterogeneous integration is in the enlightenment stage, and there is not much research invested.
Recently, the rise of high-end applications such as the Internet of Things, handheld systems, automotive electronics, high-speed computing and AI chips is increasingly requiring high computational or highly system-integrated designs. In addition to considering performance, power consumption and temperature, heterogeneous integration is becoming more and more important. The traditional method can analyze the simulation in the middle and late orders of design, and often consumes a lot of unnecessary manpower and material resources. Therefore, the ability to upgrade heterogeneous electrical analysis to the electronic system level is a manifestation of competitiveness and a future trend.
An embodiment of the present disclosure discloses a simulation system, comprising an application program, configured to generate a corresponding instruction set in accordance with an application situation of a simulation circuit; wherein the simulation circuit comprises a chip; a chip model, configured to receive the instruction set as an input to simulate operation of at least one intellectual property core of the chip via high-level languages in accordance with the intellectual property core of the chip and to generate a power consumption and an I/O logic signal of the chip; and an off-chip model, configured to construct one or more orders of RLCG (resistor-inductor-capacitor-conductor) circuit cascading models in accordance with all or part of the off-chip model abstracted by the S parameter. The application program and the RLCG circuit cascading model are integrated for simulating and analyzing power integrity and signal integrity of the simulation circuit.
The present disclosure also discloses a simulation method, implementing an application program to generate a corresponding instruction set in accordance with an application situation of a simulation circuit, wherein the simulation circuit comprises a chip, comprises generating a chip model configured to receive the instruction set as an input to simulate operation of at least one intellectual property core of the chip via high-level languages in accordance with the intellectual property core of the chip and to generate a power consumption and an I/O logic signal of the chip; generating an off-chip model configured to construct one or more orders of RLCG (resistor-inductor-capacitor-conductor) circuit cascading models in accordance with all or part of the off-chip model abstracted by the S parameter; and integrating the application program and the RLCG circuit cascading model for simulating and analyzing power integrity and signal integrity of the simulation circuit.
The present disclosure can be more fully understood by reading the subsequent detailed description with references made to the accompanying figures.
It should be understood that the figures are not drawn to scale in accordance with standard practice in the industry. In fact, it is allowed to arbitrarily enlarge or reduce the size of devices for clear illustration.
The present disclosure provides a simulation system and method, so that an electrical simulation of the system level can be achieved, and the software, the chip, the package and the PCB can be integrated together for electrical simulation.
The chip model 106 receives the instruction set from the application program 102 as an input to simulate operation of at least one intellectual property core of the chip via high-level languages in accordance with the intellectual property core of the chip and to generate a power consumption and an I/O logic signal of the chip. For example, when the smartphone is running a game, after simulating a complex computation of the chip in the smartphone, the chip model 106 generates the power consumption and the I/O logic signal of the chip. For the off-chip model 108, S parameter is used in the prior art to describe all or part of the off-chip model 108. However, the present disclosure abstracts the S parameter to construct one or more orders of RLCG (resistor-inductor-capacitor-conductor) circuit cascading models to replace the complex S parameter, so that the one or more orders of RLCG circuit cascading models can be simulated using high-level languages. The present disclosure can be used for chip-package-PCB integration simulation by simply integrating with software at the beginning of design, and does not require complex software like HSPICE to finish analyzing power integrity (PI) and signal integrity (SI) quickly. Wherein all or part of the off-chip model 108 abstracted by the S parameter is obtained by extracting all or part of the chips of the simulation system (for example, a smartphone) using an electronic design automation (EDA) tool. The application program 102, the instruction set, the chip model 106, and the off-chip model 108 are accomplished using high-level languages. In the present embodiments, the application program 102 is accomplished by QEMU, the chip model 106 is accomplished by SystemC, and the off-chip model is accomplished by SystemC-AMS. For example, the chip model 106 may be implemented by a chip simulator or a processor which executes codes of high-level language and is configured to simulate functions of the chip defined by the intellectual property core. Similarly, the off-chip model 108 may be implemented by a processor or some hardware which executes high-level language in conjunction with the extracted S parameter to construct the RLCG (resistor-inductor-capacitor-conductor) circuit model.
Commonly used EDA tools include HFSS, SIwave, Q3D, PowerSI, ExtractIM and ADS could generate the S-parameter models by extracting the models of package, PCB or components. For example, when the system is integrated, the power goes from a regulator, through components, layouts, layers, and packages, finally to the intellectual property core of the chip, and may have some loss. The extent of this loss can be described by power impedance, and the commercial software is used to model the physical design of the world outside the chip by using the electromagnetic software, which is scattering parameters (S parameters).
The off-chip model 108 searches for at least one resonant frequency in accordance with the impedance-frequency response 200 of all or part of the off-chip model 108 abstracted by the S parameter.
According to the equation 1, when R1=0, G1=0 and ω2=1/L1C1, the impedance Z(ω) has a maximum value. In more detail, the original impedance series and parallel calculations have real and imaginary parts, so the calculation is complicated, but since the frequency is constant, and the power impedance calculated by the present disclosure is also a real value, the above calculation becomes very simple. Therefore, the impedance calculation of the present disclosure is fast. The equation 1 above is used to evaluate a difference between the abstract model constructed by the present disclosure and the power impedance converted by the scattering model (S parameter) extracted by the original commercial software. Meanwhile, the equation 1 can be used to adjust the value of RLCG (that is, one or more orders of RLCG circuit cascading models) parameter.
As shown in
Then, the off-chip model 108 sets the point D as an initial point for searching resonant frequency again, and keeps searching along to the low frequency to find point F. The impedance of the point E is smaller than that of the point D, and when the impedances between one tenth of frequency f4 of the point F and the frequency fmax1 of the point D are all smaller than that of the point D, the off-chip model 108 sets the frequency f4 of the point F as a first minimum impedance frequency fmin1. According to the searching method of the impedance-frequency response 200 of all or part of the off-chip model 108 abstracted by the S parameter in
For example, if two resonance frequency points (such as point C and point D in
The off-chip model 108 first sets the value of the resistors and the conductors in the first circuit model 300 and the second circuit model 302 as 0 (that is, R1, G1, R2, G2). Then, at the frequency of one-tenth of the frequency fmax1 of the first resonance frequency point D in
Impedance error 400 is the impedance difference between the first circuit model 300 and the impedance-frequency response 200 of all or part of the off-chip model 108 abstracted by the S parameter at the first resonance frequency point D (the frequency=fmax1), that is the impedance error 400=ΔZ1=|Ztarget−Zest1|. As shown in
Similarly, by using the tri-search method, the off-chip model 108 keeps searching for the second resonance frequency point G in
After adjusting the values of L1, C1, L2 and C2, in the frequency points between the first resonance frequency point D and the second resonance frequency point G in
After adjusting the first circuit model 300 and the second circuit model 302, the RLCG circuit cascading model (such as the first circuit model 300 and the second circuit model 302) and the chip model 106 are integrated, comprising compiling the RLCG cascading model from SystemC-AMS to a first code, compiling the chip model 106 from SystemC to a second code, cascading the first code and the second code and inputting a signal generated by the application program 102, and after calculating, so that the RLCG circuit cascading model can receive the power consumption and the I/O logic signal generated by the simulation system.
According to the simulation system disclosed above, the off-chip model is configured to construct one or more orders of RLCG circuit cascading models, comprising searching for at least one resonant frequency in accordance with all or part of the off-chip model abstracted by the S parameter; and adjusting the values of the capacitor and the inductors corresponding to at least one circuit model in accordance with the resonant frequency, so that the impedance difference between each of the circuit models in the orders of RLCG circuit cascading models and all or part of the off-chip model abstracted by the S parameter is at a minimum at the corresponding resonant frequency.
According to the simulation system disclosed above, the off-chip model is configured to construct one or more orders of RLCG circuit cascading models, further comprising: adjusting the values of the resistor and the conductor that correspond to at least one circuit model in accordance with at least two resonant frequencies, so that the impedance difference between each of the circuit models in the orders of RLCG circuit cascading models and all or part of the off-chip model abstracted by the S parameter is at a minimum between the two corresponding adjacent resonant frequencies.
According to the simulation system disclosed above, the application program and the RLCG circuit cascading model, which are integrated, comprise: compiling the RLCG cascading model from SystemC-AMS to a first code; compiling the chip model from SystemC to a second code; cascading the first code and the second code and inputting a signal generated by the application program; and after calculating, the RLCG circuit cascading model can receive the power consumption and the I/O logic signal generated by the simulation system.
According to the simulation system disclosed above, the power consumption of the chip generated by the chip model is used for analyzing power integrity, and the I/O logic signal of the chip is used for analyzing signal integrity.
According to the simulation system disclosed above, the off-chip model is configured to construct one or more orders of RLCG circuit cascading models for abstracting all or part of the off-chip model to replace the S parameter.
According to the simulation system disclosed above, the application program, the instruction set, the chip model, and the off-chip model can be accomplished using high-level languages.
According to the simulation method disclosed above, the off-chip model is configured to construct one or more orders of RLCG circuit cascading models, comprising: searching for at least one resonant frequency in accordance with all or part of the off-chip model abstracted by the S parameter; adjusting the values of the capacitor and the inductors that correspond to at least one circuit model in accordance with the resonant frequency, so that the impedance difference between each of the circuit models in the orders of RLCG circuit cascading models and all or part of the off-chip model abstracted by the S parameter is at a minimum at the corresponding resonant frequency.
According to the simulation method disclosed above, the off-chip model is configured to construct one or more orders of RLCG circuit cascading models, the method further comprising: adjusting the values of the resistor and the conductor that correspond to at least one circuit model in accordance with at least two resonant frequencies, so that the impedance difference between each of the circuit models in the orders of RLCG circuit cascading models and all or part of the off-chip model abstracted by the S parameter is at a minimum between the two corresponding adjacent resonant frequencies.
According to the simulation method disclosed above, the application program and the RLCG circuit cascading model are integrated, the method comprising: compiling the RLCG cascading model from SystemC-AMS to a first code; compiling the chip model from SystemC to a second code; cascading the first code and the second code and inputting a signal generated by the application program; and after calculating, the RLCG circuit cascading model can receive the power consumption and the I/O logic signal generated by the simulation system.
According to the simulation method disclosed above, the power consumption of the chip generated by the chip mode is used for analyzing power integrity, and the I/O logic signal of the chip is used for analyzing signal integrity. At the beginning of the design of the chip model, if there is no detailed physical design, the design experience can be used to produce the best, typical and worst cases. The chip model is verified in the frequency domain and the time domain to accelerate the power integrity simulation by more than two orders and maintain high accuracy. One or more orders of RLCG circuit cascading models constructed by the off-chip model have the greatest similarity to all or part of the given off-chip model abstracted by the S parameter. That is, the impedance error between the one or more orders of RLCG circuit cascading models and all or part of the off-chip model abstracted by the S parameter is at a minimum. For example,
According to the simulation method disclosed above, the off-chip model is configured to construct one or more orders of RLCG circuit cascading models for abstracting all or part of the off-chip model to replace the S parameter.
According to the simulation method disclosed above, the application program, the instruction set, the chip model, and the off-chip model can be accomplished using high-level languages.
The ordinal in the specification and the claims of the present disclosure, such as “first”, “second”, “third”, etc., has no sequential relationship, and is just for distinguishing between two different devices with the same name. In the specification of the present disclosure, the word “couple” refers to any kind of direct or indirect electronic connection. The present disclosure is disclosed in the preferred embodiments as described above, however, the breadth and scope of the present disclosure should not be limited by any of the embodiments described above. For example, the method flow chart in
Number | Date | Country | Kind |
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107138489 | Oct 2018 | TW | national |