2-1633738-6_Datasheet PDF

Teikoku Tsushin Kogyo

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16.2.3  PLL To further facilitate clock and timing management, Cyclone II devices also contain PLL (phase-locked loop) circuits. The simplified block diagram of a Cyclone II PLL circuit is shown in Figure 16.3. It consists of a PFD (phase-frequency detector), a charge pump, a loop filter, a VCO (voltage controlled oscillator), and several frequency dividers and PS (phase selection) circuits.  The key part of a PLL is the closed feedback loop. The PFD compares the phases of the reference input clock and feedback clock and outputs their difference. The charge pump and loop filter convert the difference to a voltage level. Based on the voltage level, the VCO oscillates at a higher or lower frequency, which affects the phase and frequency of the feedback clock. The negative feedback mechanism eventually forces the feedback clock and the reference input clock to have the same frequency and phase, which is said to be phase locked .

Seiko Instruments, Inc.

Chogori Technologies

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A second key aspect of creating large, fast storage systems is scalability. This is enabled by the flexibility, expandability, and bandwidth of the interconnect. Systems have differing needs—some offer a very large array of memory devices needing many connection ports, while others are better served by aggregating relatively fewer memory subsystems, with each one providing vastly more bandwidth.

Kycon

ITT Interconnect Solutions

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A second key aspect of creating large, fast storage systems is scalability. This is enabled by the flexibility, expandability, and bandwidth of the interconnect. Systems have differing needs—some offer a very large array of memory devices needing many connection ports, while others are better served by aggregating relatively fewer memory subsystems, with each one providing vastly more bandwidth.

This is the same approach as for IMA based systems; a system architecture overview compatible with IMA is depicted in the right-hand side of the illustration. Literature and links : [1 ] Lötzke, M.: Experiences from Recent Avionics Projects. Talk given at the first symposium of the VirtuOS project partners on 15 June 2011. Berlin. [2 ] www.autosar.org [3 ] Gerlach, M.; Weißleder, S.; Hilbrich, R.: Can Cars Fly: From Avionics to Automotive: comparability of domain-specific standards. Embedded World 2011.

Hakko
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