High-speed clock network design pdf

New product introductions are the life blood of any component manufacturer and highspeed connector design is no exception. High speed clock distribution design techniques for cdc 509516250925102516 operating modes the cdc2509 has many modes of operation which aid the designer in trouble shooting, reducing power consumption and minimizing emi. High speed board design advisor high speed channel design and layout november 2007, ver. General considerations in order to perform synchronous operations such as retiming and demultiplexing on random data, high speed receivers must generate a clock. However, the exponential reduction in feature size of the. The complexity of the clock tree and the number of clocking components used depends on the hardware design. Avoid using multiple signal layers for clock signals. The layout design of the chip becomes easier by separating the global clock network from the rest. High speed system applications, 2006 education analog. This is because the timing accuracy of the clock signal can directly affect the dynamic performance of the adc. High speed board designs clock signal routing considering routing techniques can help to maximize the quality of clock transmission lines.

To minimize this influence, an adc clock source must exhibit very low levels of timing jitter or phase noise. General considerations in order to perform synchronous operations such as retiming and demultiplexing on random data, highspeed receivers must generate a clock. Clock frequency andor edge rates typical problems logic gates or flipflops dont have time to settle clock skew causes races wire interconnect acts like transmission lines. This is the third seminar book on the topic of high speed systems. The max2620 voltagecontrolled oscillator vco is capable of generating oscillator frequencies. Where electronics engineers discover the latest toolsthe design site for hardware software. It is therefore crucial to select suitable system components, which help generate a low phasejitter clock. A highspeed, lowphasenoise clock is one of the most critical elements to ensure optimum dynamic performance of the highspeed adc. In recent years, the deskewing buffers are added in the local clock network to further reduce the clock skew for the fullchip clock distribution. The high speed systems applications book is available for download. The clock trees on the package layers still have few obstacles to overcome before it is applied to the real chips, which will be studied in this chapter. This document assumes familiarity with the following tools and support collateral.

It emulates the clock recovery in a reference receiver, which makes jitter measurements possible. High speed clock and data recovery techniques behrooz abiri. High speed clock network design published in ieee circuits and devices magazine volume 20 issue 5. High speed frequency dividers in wireless systems design issues. This chapter describes a clock distribution system with low voltage swing clock signals 34. Challenges in the design of highspeed clock and data. Use small form factor capacitors, no larger than 0402, c 1 nf. Outstanding high speed clock network design, by qing k.

Download highspeed clock network design, by qing k. Figure 10 is an example of separating traces for crosstalk. On a small chip, the clock distribution network is just a wire. Highspeed clock network design is a collection of design concepts, techniques. M95080df 8kbit spi bus eeprom with highspeed clock.

A clock distribution network for microprocessors solidstate. Noise on the analog supply line can significantly increase the output jitter and the total system skew margin. Many techniques have been used in the clock network design for high performance microprocessors. Measuring jitter for clocks in highspeed digital designs has become increasingly challenging. Jitter reduction on high speed clock signals by tina harriet smilkstein b. High speed clock and data recovery techniques behrooz abiri master of applied science graduate department of electrical and computer engineering university of toronto 2011 this thesis presents two contributions in the area of high speed clock and data recovery systems. Highspeed layout guidelines in figure 5, the case with an open end highimpedance input stage of the sink is simulated. This lecture explores the issues involved and the sources of clock skew. This technique adds a stop clock signal for the clock buffer to gate the clock when the clock is not needed for a portion of the clock distribution network. Read or download highspeed clock network design book by qing k. Avaliable format in pdf, epub, mobi, kindle, ebook and audiobook. This chapter shows the clock tree design flow in the timing optimised layouts based on the place and route cad tools 61.

Design a lowjitter clock for highspeed maxim integrated. Definition of high speed the speed at which one or more digital abstractions fail, as a direct consequence of the circuit speed speed. Design techniques for ultrahighspeed timeinterleaved analogtodigital converters adcs by yida duan a dissertation submitted in partial satisfaction of the requirements for the degree of doctor of philosophy in engineering. Highspeed clock network design is a collection of design concepts. We will summarize the cad algorithms developed by the author in the ph. A high speed, lowphasenoise clock is one of the most critical elements to ensure optimum dynamic performance of the high speed adc. The design does not aim to latch the data at the exact midpoint. Verifying the true jitter performance of clocks in highspeed. High speed system applications, edited by walt kester, analog devices, 2006, isbn1566199093. Clock dividers in order to improve signal quality and reduce jitter and isi for high speed clock distribution, a clock divider is generally applied 2, 4, and 5. The balanced clock routing algorithms have been researched by many people 716. The bit period for these signals is compressed to tn, multiplexed.

These contributions are focused on the fast phase recovery and adaptive. High speed design techniques, edited by walt kester, analog devices, 1996, isbn0916550176. For differential trace, figure 9 shows proper routing techniques are important for highspeed design. The virtex ultr ascale design vcu108 sources a 156. Clock network synthesis in the physical design flow.

While there may be talk in the industry that 25 gbits design is done and challenges have been solved, its far from over, according to connector makers. Design and implementation of highspeed clock recovery. Section 3 covers dacs, dds, plls, and clock distribution circuits, and section 4 on pc board layout, grounding, and decoupling represents a very comprehensive treatment of a critical aspect of system design. Understanding highspeed signals, clocks, and data capture. August 26, 2016 leave a comment component sourcing, featured, featured articles, interconnects by gina roos. Highspeed applications using ultrafast data converters in their design often require an extremely clean clock signal to make sure an external clock source does not contribute undesired noise to the overal dynamic performance of the system. A selfadaptive and pvt insensitive clock distribution. High speed clock network design is a collection of design concepts, techniques and research works from the author for clock distribution in microprocessors and high performance chips.

Heavy design overheads and due to crosstalk, clock skew effects and high io pin count. Your project will be the design of a circuit that processes the input data from a highspeed io. Typical high speed data converter system using the max104 adc and a pllbased, lowjitter clock. High speed design techniques, 1996 education analog. It includes the clocking circuitry and devices from clock source to destination. The four 90degree phaseshifted clocks generated by. This paper proposed a clock recovery design that adjusts the output clock earlier or later constantly according to the phase relationship between the input data and the feedback clock. M horowitz ee371 lecture 2 2 readings readings techniques for highspeed implementation of nonlinear cancellation, sanjay kasturia and jack h. Highspeed clock recovery channel a channel b channel c individual channels are modulated at high data rates channels ac, more would be used in an actual system. The m95080w can operate with a supply voltage from 2. For best performance results, a filter network as shown. Microprocessor clock distribution examples springerlink. High speed clock network design full online free reading feb 16, 2020.

This is the second high speed seminar from analog devices, representing a major update of the material covered in the 1990 high speed design seminar. Measuring jitter for clocks in high speed digital designs has become increasingly challenging. The alpha 21064 demonstrated a clock grid, as conceptually shown in figure 2. In general, it doesnt matter where the dc blocking capacitors are placed on the tx or rx side. Plls can be used to double or multiply the input clock frequency, such as outputting the clock with 2x and 4x clock frequencies. Clock sources one of the most important subcircuits within a high speed data conversion system is the clock source. We have seen that generating and distributing clocks with little skew is essential to high speed circuit design.

Embedding the clock tree during the dme topdown phase. Clock networks typically include a network that is used to distribute a global reference to various parts of the chip and a. Highspeed board designs clock signal routing considering routing techniques can help to maximize the quality of clock transmission lines. As further outlined in interbyte clocking, the clock network in the bitslices performing the qbc function is called the interbyte clock. A clock tree is a clock distribution network within a system or hardware design. Typical highspeed data converter system using the max104 adc and a pllbased, lowjitter clock. Section 1 of this seminar book gives a brief overview of popular high speed converter architectures and how specific applications often dictate the optimum architecture. Heavy design overheads and due to crosstalk, clockskew effects and high io pin count. Highspeed clock network design springer for research. The clock gating technique is often used to reduce the wasted power in the clock distribution.

The green one dashed is the real signal at the clock s output and the blue line is at the end. The goal is to develop a cad tool, which can route the clock trees in the balanced form to minimize the clock skew. High speed clock network design published in ieee circuits and devices magazine volume 20 issue 5 sept oct 2004 article pages 36 36 date of. Clock dividers in order to improve signal quality and reduce jitter and isi for highspeed clock distribution, a clock divider is generally applied 2, 4, and 5. Highspeed links overview traditional parallel communication not suitable for interic data transport in highspeed data links. Clocking, clock skew, clock jitter, clock distribution and. Zhu publication is consistently being the best friend for investing little time in your workplace, evening time, bus, and almost everywhere. Design a lowjitter clock for highspeed data converters. Balanced clock trees or clock grids are usually used to minimize the clock skew in the clock distribution. Electrical engineering and computer sciences in the graduate division of the university of california, berkeley. Wagner, a survey of clock distribution techniques in high speed computer systems, stanford computer systems laboratory, crc technical report no.

Pdf high performance clock distribution for cmos asics. Highspeed board design advisor altera corporation 4 how to design with dc blocking capacitors use cutouts under the smt launch pads to a depth at least equal to the pad diameter or within 10 mils under the capacitor. High speed system applications, 2006 education analog devices. It will be a great way to simply look, open, and read guide high speed clock network design, by qing k. High speed clock distribution design techniques for cdc. There is some debate as to how the reference receiver should emulate reality. Clock driven design planning berkeley eecs university of. Clock network simulation methods springer for research. High speed links overview traditional parallel communication not suitable for interic data transport in high speed data links. The clocks are driven horizontally from a clock spine at the center so there is very little skew near the. Pcie gen4, for example, introduces data rates of up to 16 gigatransfers per second gts with a corresponding jitter limit of 500 fs rms for the reference clock.

Design techniques for ultrahighspeed timeinterleaved. Features in conjunction with the ultrascale architecture selectio resources user guide ug571 ref 1, this application note further explains the native highspeed io primitives available in. High speed communication circuits and systems lecture 14 high speed frequency dividers michael perrott. Verifying the true jitter performance of clocks in high. On the cdc2509 banked operation is achieved by using 1g and 2g to enable or disable banks 1y and 2y respectively. Outstanding highspeed clock network design, by qing k. The four 90degree phaseshifted clocks generated by clock dividers run at a quarter of the data rate. Wagner, a survey of clock distribution techniques in highspeed computer systems, stanford computer systems laboratory, crc technical report no.

Jitter reduction on highspeed clock signals by tina harriet smilkstein b. High speed design techniques, 1996 education analog devices. High speed clock and data recovery for serdes applications. It will be a great way to simply look, open, and read guide highspeed clock network design, by qing k. Qing k highspeed clock network design description please.

Careful design of the clock generation and distribution circuits is now required for all high performance. Design of lowpower highspeed links mit opencourseware. An optical pulse generator forms highspeed pulses at rates less than the period of the transmitted data. University of california at berkeley 2003 a dissertation submitted in partial satisfaction of the requirements for the degree of doctor of philosophy in engineering electrical engineering and computer science in the. Highperformance and lowpower clock network synthesis in the. There are several design methodologies proposed to design effective clock distribution networks. Use th e following routing techniques for clock signals. New product introductions are the life blood of any component manufacturer and highspeed connector design is. Highspeed clock network design is a collection of design concepts, techniques and research works from the author for clock distribution in microprocessors and highperformance chips.

This processing is generally done in a mixed signal manner today, but. Find all the books, read about the author, and more. Routing multiple clocks with little skew between the clocks is even harder. The green one dashed is the real signal at the clocks output and the blue line is at the end. It shows one example of automation cad tools used for the clock network design.

In addition to high speed op amps, adcs, and dacs, the book has a detailed discussion of rfif subsystems. Clock sources one of the most important subcircuits within a highspeed data conversion system is the clock source. Pdf high speed clock and data recovery for serdes applications. Cdn design with balanced power and timing performance. As supply voltages have scaled down, legacy parallel bus voltages have not thus making them incompatible with modern processes. Dlls, which are also called deskewing buffers, are used to compensate the clock skew resulting from the delay mismatch in the clock network.