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... | @@ -11,7 +11,7 @@ extended to more complex projects**. |
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# Application
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# Application
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A GALS circuit consists of a set of **locally synchronous modules** communicating with each other via asynchronous wrappers. In this way, each synchronous subsystem ("clock domain") can run on its own **locally generated independent clock (frequency)**, while sharing data with their neighboring modules by using **asynchronous micropipelines**.
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A GALS circuit consists of a set of **locally synchronous modules** communicating with each other via **asynchronous wrappers**. In this way, each synchronous subsystem ("clock domain") can run on its own **locally generated independent clock (frequency)**, while sharing data with their neighboring modules by using **asynchronous micropipelines**.
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One of the critical **advantages of GALS** over pure synchronous designs is the **much lower electromagnetic interference (EMI)**. The CMOS circuit (logic gates) requires relatively large supply current when changing state from 0 to 1. These changes are aggregated for synchronous circuit as most changes are initialized by an active clock edge. Therefore, **large spikes on supply current occur at active clock edges in synchronous designs**. These spikes can cause large electromagnetic **conducted and radiated interference**, and may ultimately lead to **circuit malfunction**. In order to limit these spikes large number of decoupling capacitors are used, but this is not always possible and no more than hack for the actual problem.
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One of the critical **advantages of GALS** over pure synchronous designs is the **much lower electromagnetic interference (EMI)**. The CMOS circuit (logic gates) requires relatively large supply current when changing state from 0 to 1. These changes are aggregated for synchronous circuit as most changes are initialized by an active clock edge. Therefore, **large spikes on supply current occur at active clock edges in synchronous designs**. These spikes can cause large electromagnetic **conducted and radiated interference**, and may ultimately lead to **circuit malfunction**. In order to limit these spikes large number of decoupling capacitors are used, but this is not always possible and no more than hack for the actual problem.
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... | @@ -21,9 +21,9 @@ Another solution is to use a **GALS design style**: there are different (e.g. ph |
... | @@ -21,9 +21,9 @@ Another solution is to use a **GALS design style**: there are different (e.g. ph |
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# Technical Details
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# Technical Details
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The original AsyncArt research project was conducted by **Javier Garcia-Lasheras** between 2005 and 2007 with the support of the **Communication, Signal and Microwaves group** of the [Public University of Navarre](https://www.unavarra.es/?languageId=1). The target for this research was to demonstrate the advantages of a full featured System-on-Chip ASIC implemented with the GALS approach. After heavy testing in FPGAs, an ASIC chip dubbed PNX-2006 was successfully built, demonstrating Asynchronous Network-on-Chip capabilities and active power consumption and EM interference reduction techniques.
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The original AsyncArt research project was conducted by **Javier Garcia-Lasheras** between 2005 and 2007 with the support of the **Communication, Signal and Microwaves group** of the [Public University of Navarre](https://www.unavarra.es/?languageId=1). The target for this research was to demonstrate the advantages of a full featured System-on-Chip ASIC implemented with the GALS approach. After heavy testing in FPGAs, an **ASIC chip dubbed PNX-2006** was successfully built, demonstrating Asynchronous Network-on-Chip capabilities and active power consumption and EM interference reduction techniques.
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During the research, we noticed that the FPGA prototypes performed very close to the physical limit of the technology while incurring in a very low logic overhead. Indeed, they performed far better than the PNX-2006, because while the foundry we used for **the ASIC was based on 0.5 micrometer CMOS process, the FPGA devices for the prototypes were based on 45 and 90 nanometers processes**. In order to allow further research on this topic, we published the **internal technical details for our GALS implementation for FPGAs** in the following paper:
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During the research, we noticed that **the FPGA prototypes performed very close to the physical limit of the technology** while incurring in a **very low logic overhead**. Indeed, they performed far better than the PNX-2006, because while the foundry we used for **the ASIC was based on 0.5 micrometer CMOS process, the FPGA devices for the prototypes were based on 45 and 90 nanometers processes**. In order to allow further research on this topic, we published the **internal technical details for our GALS implementation for FPGAs** in the following paper:
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- [Efficient implementation of GALS systems over commercial
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- [Efficient implementation of GALS systems over commercial
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synchronous FPGAs: a new
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synchronous FPGAs: a new
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