/Contents [193 0 R 194 0 R] When you enable write-leveling in the controller, it does the following steps: The figure below shows the write-leveling concept. Extract the exact physical location of such cells. This concept of DRAM Width is very important, so let me explain it once more a little differently. The address bits registered coincident with the ACTIVATE Command are used to select the BankGroup, Bank and Row to be activated (BG0-BG1 in x4/8 and BG0 in x16 selects the bankgroup; BA0-BA1 select the bank; A0-A17 select the row). /Type /Pages A DRAM chip is equivalent to a building full of file cabinets, Bank Group Identifies the floor number, Bank Address Identifies the file cabinet within that floor where the file you need is located. 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Generate an accurate Netlist, including parasitic values and input loads for the SPICE simulator. endobj 12 0 obj From the above loop the PHY can determine for what write-delay range it reads back good data, and hence it can figure out the left and write edges of the write-data eye. 64 0 obj endobj 40 0 obj "Interconnect Tech of the Year" at DesignCon 2007: Report an Issue | Instead of issuing an explicit PRECHARGE command to deactivate a row, the RDA (Read with Auto-Precharge) and WRA (Write with Auto-Precharge) commands can be used. Or you could choose to have 2 individual 8Gb discrete devices soldered down on the PCB (because 2x8Gb devices happen to be cheaper than 1x16Gb). Learn how your comment data is processed. This webinar was originally held on February 11, 2021. These cookies ensure basic functionalities and security features of the website, anonymously. endobj Avalon -MM Slave Read and Write Interfaces, 9.1.4. << Build data structure of all pin locations and metal layers they connect. 2 0 obj /CropBox [0 0 612 792] Say you intend to do a WRITE operation, during initialization you tell the DRAM what the CAS Write Latency is by programming one of its Mode Registers (CWL is the time delay between the column address and data at the inputs of a DRAM), and you have to honor this timing parameter at all times. Delay unit, located at the DDR PHY, contains a physical chain of basic delay elements. /Rotate 90 Activity points. The memory controller needs to account for the board trace delays and the fly-by routing delays and launch Address and Data with the correct skew between them so that the Address and Data arrive at the memory with CWL latency between them. /Parent 7 0 R Functional Description of the SDRAM Controller Subsystem, 4.13. /Rotate 90 /Rotate 90 /CropBox [0 0 612 792] The resistance is even affected due to voltage and temperature changes. /Parent 6 0 R /Rotate 90 /Parent 3 0 R endobj /CropBox [0 0 612 792] Or put it another way, it is the number of bits loaded into the Sense Amps when a row is activated. J;NFx It is true that DDR1 and DDR2 RAM are no longer in use, and in fact, DDR1 memory is long gone. 0000005476 00000 n >> 37 0 obj /Parent 6 0 R See Intels Global Human Rights Principles. 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The cookies is used to store the user consent for the cookies in the category "Necessary". 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The PHY and controller, along with user logic are typically part of the same FPGA or ASIC. 7 0 obj /Resources 159 0 R /Resources 93 0 R /Contents [88 0 R 89 0 R] HIGH activates internal clock signals and device input buffers and output drivers. /Resources 150 0 R Then you could pick a single 8Gb x8 device or two 4Gb x4 devices and connect them in a "width cascaded" fashion on the PCB. /CropBox [0 0 612 792] >> endobj Sreenivas, Founder, VLSI Guru. application/pdf It is responsible for sending data back during reads and receiving data during writes. This is not a complete list of IOs, only the basic ones are listed here. /Resources 222 0 R The specification, available for download at DDR is being developed by expert contributors from recognized leaders in the semiconductor, IP and electronic design automation (EDA) industries, including: ARM, Denali, Intel, Rambus,Samsung, and Synopsys. Transim powers many of the tools engineers use every day on manufacturers' websites and can develop solutions for any company. MPR (Multi Purpose Register) Pattern Write isn't exactly a calibration algorithm. /Resources 87 0 R This basic time de lay varies over temperature, and IC manufacturing. 23 0 obj /Resources 99 0 R << This means there are only 2^10 = 1K columns. Update netlist inside the generic EDA flow with a new clock mesh structure. /Resources 96 0 R This is how data is written in and read out. endobj HTn1++!#F$vAPgEzv]\iUR MtX]$5Lq*YV>|rwuKa,Kiol8 z.Ybpg"], Microsoft PowerPoint - AN108_Mazyar_Razzaz_DDR_Basics,_Configuration_and_Pitfalls_v2_ca(2).ppt. Figure 1: DDR4 Top Level Bank Group, Bank, Row, Column The top-level picture shows what a DRAM looks like on the outside. Acrobat Distiller 8.1.0 (Windows) <> /CropBox [0 0 612 792] /Parent 11 0 R << endobj DDR4 SDRAMs are very prevalent in devices that use ASICs and FPGAs. When a ZQCL command is issued during initialization, this DQ calibration control block is enabled and an internal comparator within the DQ calibration control block tunes the p-channel devices using VOH[0:4] until the voltage is exactly VDDq/2 (A classic resistor divider). /Contents [103 0 R 104 0 R] /MediaBox [0 0 612 792] Features of the SDRAM Controller Subsystem, 4.2. This website uses cookies to improve your experience while you navigate through the website. Figure 9 shows the timing diagram of a WRITE operation. 56 0 obj Verify equal loading of all cells, to achieve the exact same timing effect. 65 0 obj Delay-Locked-Loop (DLL) type and frequency. This external precision resistor is the "reference" and it remains at 240 at all temperatures. endobj endobj /Parent 7 0 R /Rotate 90 49 0 obj /MediaBox [0 0 612 792] >> To better understand the following sections, let's assume you have a system which looks like this - An ASIC/FPGA/Processor with 1 DIMM module. This value is then copied over to each DQ's internal circuitry. /Type /Pages << /Contents [124 0 R 125 0 R] endobj 18 0 obj /Resources 183 0 R David Maliniak joined Teledyne LeCroy in 2012 after more than 30 years as a writer/editor in the electronics B2B press, most of which was spent at Electronic Design covering EDA and T&M. UniPHY-Based External Memory Interface Features, 10.7.1. /Resources 213 0 R << /Parent 10 0 R The clock runs at half of the DDR data rate and is distributed to all memory chips. /Resources 192 0 R /Contents [139 0 R 140 0 R] A single configurable Address/Command macro-cell abuts to a Data Byte macro, and interfaces the address and control signals to the SDRAM. In this article we explore the basics. Creating and Connecting the UniPHY Memory Interface and the Traffic Generator in Platform Designer, 9.1.3.2. The controller typically has the capability to re-order requests issued by the user to take advantage of this. endobj 0000002123 00000 n 7 0 obj << Before a read/write to a different row in the same bank can be performed, the current open row has to be de-activated using a PRECHARGE command. Command signals are clocked only on the rising edge of the clock. /Type /Page /Resources 126 0 R /Resources 84 0 R DDR PHY supports an ongoing measurement process, to determine what is the time delay of the basic delay element. /Contents [217 0 R 218 0 R] >> /CropBox [0 0 612 792] endstream endobj 187 0 obj <> endobj 188 0 obj <> endobj 189 0 obj <>/ColorSpace<>/Font<>/ProcSet[/PDF/Text/ImageC]/ExtGState<>>> endobj 190 0 obj <>stream The auto precharge command is issued via A10, and select BurstChop4 (BC4) or BurstLength8 (BL8) mode is selected via A12, if enabled in the mode register. \SwZ.P1KWz Gw+,]%VkYK*,]%L1uW(acrte =d8K~#=aE!GWvSV9KZ!^tP!KWzPC6U,]5B7%D^T;HKC\BXh2TGP:rB|&E3a%6J(.hYZ}!->x]}!7ZxmEGI1(ag,t?FW3rZx&\SCgM;3agRL9 I}B)96;P] 1;y=D4[(f]c)MXBgll#5ieS'2KWtHj$T~fCz_d`|cptfP&c J\g/r$[O!KWn&?.P,{mwc1Kw SC(Bc)tpcwVH]tG;t|cELip%"Lcp's*GD"ol/N>tfY;?*sCCjx+.o~v3}:=at8dkw,)bIA"HX!ChD8|,{`wZ[t.jyXXr,;)33 b$ auG^u@OrgT0U fZ;(4/uh e |~ow/` aW The DDR3 PHY IP provides the Industry standard DDR PHY Interface (DFI) bus at the local side to interface with the Memory . /CropBox [0 0 612 792] 22 0 obj /Parent 9 0 R The address bits registered coincident with the Read or Write command are used to select the starting column location for the burst operation. uuid:ea006926-0607-4372-97cb-c5fec11e43e8 /MediaBox [0 0 612 792] 13 0 obj /Rotate 90 You can also try the quick links below to see results for most popular searches. >> 23 0 obj Read Data Buffer and Write Data Buffer, 5.3.5. 26 0 obj This video covers the steps the DDR-PHY sequences. endstream /Rotate 90 /MediaBox [0 0 612 792] Writing a Predefined Data Pattern to SDRAM in the Preloader, 5.1. In DDR4 the termination style of the data lines (DQ) was changed from CTT (Center Tapped Termination, also called SSTL Series-Stud Terminated Logic) to POD (Pseudo Open Drain). endobj endobj endobj 27 0 obj The memory controller (or PHY). It requires every engineer working on SoC to be well versed with DDR protocol concepts including DDR addressing, DDR memory organization, DDR wrapper, DDR controller and DDR PHY. endobj This step is also called RAS - Row Address Strobe. 13K views 2 years ago PolarFire FPGA Microchip's DDR-PHY is an integral part of the PolarFIre FPGA and Polarfire SOC memory subsystem. in journalism from New York University. Soft Memory Interface to Hard Memory Interface Migration Guidelines, 4.1. High level introduction to SDRAM technology and DDR interface technology. This cookie is set by GDPR Cookie Consent plugin. To READ from memory you provide an address and to WRITE to it you additionally provide data. /Type /Page The most common ones are: All the above algorithms are performed by the memory controller and usually require you to only enable/disable each algorithm through a register and take action in case failures are reported. startxref << /Resources 153 0 R Input your search keywords and press Enter. If you would like to be notified when a new article is published, please sign up. %PDF-1.4 % Because of the nature of CMOS devices, these resistors are never exactly 240. David Maliniak joined Teledyne LeCroy in 2012 after more than 30 years as a writer/editor in the electronics B2B press, most of which was spent at Electronic Design covering EDA and T&M. ;a?3a?BcZV46DX|T!-,L84*) '1>$Uq8tXHa6YA9(qeJ=ijYma=a,-DBErXr||>Js(fls By continuing to browse the site you are agreeing to our use of cookies in accordance with our Cookie Policy. Another thing to note is that, the width of DQ data bus is same as the column width. The 240 resistor leg within a DQ circuit is a type of resistor called "Poly Silicon Resistor" and is, typically, slightly larger than 240 (Poly silicon resistor is a type of resistor that is compatible with CMOS technology). . Update the actual path delay and transition for all leaf pins. 27 0 obj endobj /Type /Page 31 JEDEC is the standards committee that decides the design and roadmap of DDR memories. To ensure the DDR channel robustness during mission mode, the memory interface on the SoC and the DRAM are trained during initialization after power-up. So, from the ASIC/Processor's point of view each DRAM memory on the DIMM is located at a different distance. /Rotate 90 x16 devices have only 2 Bank Groups whereas x4 and x8 have 4 as shown in figure 2. This voltage reference is called VrefDQ. When you activate a row, the whole page is loaded into the Sense Amps, so multiple reads to an already open page are lesser expensive because you can skip the first step of row activation. In order to tune these resistors to exactly 240, each DRAM has. 36 0 obj <> >> endobj DDR Basics, Register Configurations & Pitfalls July, 2009 Mazyar Razzaz, Applications Engineer. <> Please check your browser settings or contact your system administrator. /Resources 174 0 R SDRAM Controller Address Map and Register Definitions, 4.6.4.9. A DDR interface entails each DRAM chip transferring data to/from the memory controller by means of several digital data lines. /Contents [211 0 R 212 0 R] Meanwhile, DDR4-3200 operates at a 1600 MHz clock, and a 1600 MHz clock cycle takes only 0.625ns. << Or from the DIMM's point of view, the skew between clock and data is different for each DRAM on the DIMM. 15 0 obj These are dual function inputs. Please click here to continue without javascript.. Since each DRAM on the DIMM is located at a different distance, when a READ is issued each DRAM on the DIMM will see the READ command at different times and subsequently the data from each DRAM arrives at the ASIC/Processor at different times. Here's another explanation which is more accurate and technical -- 3 0 obj /Kids [63 0 R 64 0 R 65 0 R] >> endobj endobj Nios II-based Sequencer Data Manager, 1.7.1.7. DDR4 basics - Free download as PDF File (.pdf), Text File (.txt) or read online for free. 4 0 obj Using this dat,a the DQ is centered to the DQS for writes. endobj Ck!@VY@0GT,iY Gc7ie8NrIucYB6(%,L\G Build a data structure of all logic cells with respect to the clock type and polarity, and the cluster to which they belong, from the floorplan. The memory returns the pattern that was written in the previous MPR Pattern Write step. /Type /Page Well, the DRAM interprets the ACT_n, RAS_n, CAS_n & WE_n inputs as commands based on the truth table below. A good place to start is to look at some of the essential IOs and understand what their functions are. /Parent 10 0 R Thanks much. << /Rotate 90 Basics PHYSICAL ORGANIZATION . /CropBox [0 0 612 792] /ModDate (D:20090708193957-07'00') Functional DescriptionExample Designs, 13. Creating a Top-Level File and Adding Constraints, 4.14.1. /Resources 123 0 R << /Type /Page % /Parent 8 0 R More in this below. >> Replacing the ALTMEMPHY Datapath with UniPHY Datapath. It requires every engineer working on SoC to be well versed with DDR protocol concepts including DDR controller, DDR PHY, DDR memory, etc. The exact physical dimensions dictated by the I/Os and abutment macros. Physical bank sizes up to 4GB, total memory up to 16GB per DDR2 and DDR3 Resource Utilization in Arria II GZ Devices, 10.7.3. // No product or component can be absolutely secure. /Parent 9 0 R DDR4 DRAMs contain four 8-bit programmable registers called MPR registers that are used for DQ bit training (i.e., Read and Write Centering). /Type /Page , You can download the DFI specification from here, DRAM is active only when this signal is HIGH. The following sections go into more detail about what the controller does when you enable each of these algorithms. >> endobj The DFI Group included several interface improvements in this newest specification. 19 0 obj /Parent 6 0 R . The top-level picture shows what a DRAM looks like on the outside. >> << /CropBox [0 0 612 792] We also use third-party cookies that help us analyze and understand how you use this website. Nios II-based Sequencer Calibration and Diagnostics, 1.9.2.1. $E}kyhyRm333: }=#ve /Rotate 90 Every PCB layout is different so this tuning capability is required to improve signal integrity, maximize the signal's eye-size and allow the DRAM to operate at high-speeds. << /Contents [148 0 R 149 0 R] /MediaBox [0 0 612 792] To that end, the strobe (DQS) signal is a differential "bursted clock" that only functions during read and write operations. Similar to the read centering step, the purpose of write centering is to set the write delay for each data bit so that write data is centered on the corresponding write strobe edge at the DRAM device. David earned a B.A. /Rotate 90 /Type /Page /CropBox [0 0 612 792] 50 0 obj /Count 10 Lecture 12: DRAM Basics Today: DRAM terminology and basics, energy innovations. Qf Ml@DEHb!(`HPb0dFJ|yygs{. 2 0 obj /Contents [82 0 R 83 0 R] In a device such as a network switch or router, there could be changes in Voltage and Temperature during its course of operation. <> Differential clock inputs. /Resources 147 0 R >> PScript5.dll Version 5.2.2 /Rotate 90 The DRAM is a fairly dumb device. /Parent 7 0 R DDR4 basics in FPGA point of view. Nios II-based Sequencer SCC Manager, 1.7.1.4. ) or Read online for Free FPGA point of view obj this video covers the steps the DDR-PHY.! De lay varies over temperature, and IC manufacturing for writes File (.pdf ), File! ( Multi Purpose Register ) Pattern Write step and can develop solutions for any company and..., contains a physical chain of basic delay elements Preloader, 5.1, 4.13 the exact physical dictated. 2 Bank Groups whereas x4 and x8 have 4 as shown in figure 2 DDR memories distance! All pin locations and metal layers they connect % PDF-1.4 % Because of the essential IOs and what. Controller Address Map and Register Definitions, 4.6.4.9 is published, please sign up > 23 0 this. /Resources 153 0 R < < this means there are only 2^10 = columns. Newest specification /Type /Page, you can download the DFI specification from here, DRAM active! Obj Delay-Locked-Loop ( DLL ) type and frequency Register Definitions, 4.6.4.9 Read from memory you provide Address. Shows what a DRAM looks like on the truth table below only on the is... Generator in Platform Designer, 9.1.3.2 tools engineers use every day on manufacturers websites! This webinar was originally held on February 11, 2021 Address Strobe during and... Transim powers many of the website, anonymously R 104 0 R < < this means are... 123 0 R SDRAM controller Subsystem, 4.13 of basic delay elements loading all! As commands based on the outside, 5.1 R > > Replacing the ALTMEMPHY Datapath with UniPHY Datapath,.... Ddr Interface technology mpr ( Multi Purpose Register ) Pattern Write step newest specification whereas x4 and x8 4... Dll ) type and frequency reads and receiving data during writes Rights Principles features... 6 0 R > > 23 0 obj endobj /Type /Page 31 JEDEC is the reference. Row Address Strobe the Pattern that was written in the Preloader, 5.1 /Rotate... Actual path delay and transition for all leaf pins Subsystem, 4.2 are listed here 612 792 ] /ModDate D:20090708193957-07'00... 7 0 R ddr4 basics - Free download as PDF File (.pdf ), File... 99 0 R See Intels Global Human Rights Principles the website, anonymously digital data lines tools use. Controller Address Map and Register Definitions, 4.6.4.9 Designs, 13 for writes figure 2 obj memory. New ddr phy basics is published, please sign up actual path delay and transition all. Sdram technology and DDR Interface technology the outside memory you provide an Address and to Write ddr phy basics. It is responsible for sending data back during reads and receiving data during writes Text File.txt... In figure 2 x8 have 4 as shown in figure 2 is as. % PDF-1.4 % Because of the tools engineers use every day on manufacturers ' websites and develop. D:20090708193957-07'00 ' ) Functional DescriptionExample Designs, 13 and Read out for any company design roadmap... To the DQS for writes of DRAM width is very important, so let me explain once! From memory you provide an Address and to Write to it you additionally provide data, 2021 reference '' it. & WE_n inputs as commands based on the rising edge of the nature of CMOS devices, resistors! Multi Purpose Register ) Pattern Write is n't exactly a calibration algorithm this concept of DRAM is! And to Write to it you additionally provide data, 4.14.1 digital data lines /parent 8 0 R < /resources. Write step of basic delay elements have 4 as shown in figure 2 are only 2^10 1K... To Read from memory you provide an Address and to Write to it you additionally provide data data written. And abutment macros dictated by the I/Os and abutment macros /resources 153 0 R > > the! Endobj /Type /Page Well, the width of DQ data bus is same the! Manufacturers ' websites and can develop solutions for any company how data is written in and Read out Rights.. Look at some of the essential IOs and understand what their functions are what a DRAM like... Precision resistor is the standards committee that decides the design and roadmap of memories. Precision resistor is the standards committee that decides the design and roadmap of DDR.. R 104 0 R ddr4 basics in FPGA point of view each DRAM has the DQ is to! From the ASIC/Processor 's point of view DEHb! ( ` HPb0dFJ|yygs { Definitions 4.6.4.9! Width is very important, so let me explain it once more a little differently width of data. > 37 0 obj this video covers the steps the DDR-PHY sequences never exactly 240 Text... Sections go into more detail about what the controller typically has the capability to requests! The basic ones are listed here % PDF-1.4 % Because of the nature of devices! Width of DQ data bus is same as the column width DDR memories cookie is set by GDPR cookie plugin. Row Address Strobe the actual path delay and transition for all leaf pins Map and Definitions! Of DRAM width is very important, so let me explain it once more a little differently to at... Sdram controller Subsystem, 4.2 the exact physical dimensions dictated by the I/Os and abutment macros written and... Timing effect 6 0 R Functional Description of the tools engineers use every day manufacturers... Controller by means of several digital data lines I/Os and abutment macros DQ data bus is as. And metal layers they connect 2^10 = 1K columns is very important so. The clock -MM Slave Read and Write data Buffer, 5.3.5 ( or PHY ) same... Update Netlist inside the generic EDA flow with ddr phy basics new article is published, sign. Sreenivas, Founder, VLSI Guru keywords and press Enter a little differently memory! Dll ) type and frequency please check your browser settings or contact your system administrator DRAM is! To be notified when a new clock mesh structure navigate through the,! Please sign up cookies is used to store the user to take advantage of this advantage of this to is! R SDRAM controller Address Map and Register Definitions, 4.6.4.9 you enable each of these algorithms ALTMEMPHY with... Cookies is used to store the user to take advantage of this exact same timing effect develop for. Active only when this signal is high the truth table below physical chain of delay... Shows the timing diagram of a Write operation to improve your experience while navigate! And Connecting the UniPHY memory Interface and the Traffic Generator in Platform Designer, 9.1.3.2 2^10! Over to each DQ 's internal circuitry by the user consent for the cookies is used to the! Ddr PHY, contains a physical chain of basic delay elements inside the generic EDA flow with a clock! And IC manufacturing dimensions dictated by the user consent for the cookies is used to store the user take... Endobj this step is also called RAS - Row Address Strobe Top-Level picture shows what DRAM... Article is published, please sign up [ 103 0 R more this... Typically part of the SDRAM controller Subsystem, 4.13 website uses cookies to improve your experience while you through... Accurate Netlist, including parasitic values and input loads for the SPICE simulator all temperatures obj Using this,... 147 0 R more in this below the resistance is even affected due to and... The generic EDA flow with a new article is published, please sign up it! Interface Migration Guidelines, 4.1, 4.6.4.9 qf Ml @ DEHb! ( ` HPb0dFJ|yygs { your... Webinar was originally held on February 11, 2021 copied over to each DQ 's internal circuitry > please your. Controller by means of several digital data lines, and IC manufacturing R this is how is! Advantage of this 7 0 R 104 0 R See Intels Global Human Rights Principles data... Inside the generic EDA flow with a new clock mesh structure as PDF File (.txt ) or online... Clocked only on the rising edge of the nature of CMOS devices these! Of this additionally provide data memory returns the Pattern that was written in and Read out the Datapath. The DQS for writes ( or PHY ) column width parasitic values and input loads for the cookies in category..., contains a physical chain of basic delay elements in FPGA point of view each has... Exactly a calibration algorithm /resources 96 0 R ] /MediaBox [ 0 0 612 ]... > Replacing the ALTMEMPHY Datapath with UniPHY Datapath this website uses cookies to improve your experience you... Cells, to achieve the exact same timing effect the website, anonymously and x8 4. And abutment macros a fairly dumb device ( or PHY ) and IC manufacturing very,... Cas_N & WE_n inputs as commands based on the DIMM is located at a different distance mpr Write... Buffer and Write Interfaces, 9.1.4 and DDR Interface technology -MM Slave Read Write... And x8 have 4 as shown in figure 2 is responsible for sending data back during reads receiving! The outside structure of all cells, to achieve the exact same effect. Memory you provide an Address and to Write to it you additionally provide data for the SPICE.! Cmos devices, these resistors are never exactly 240, each DRAM chip transferring data to/from memory! To it you additionally provide data search keywords and press Enter Read and Write Interfaces, 9.1.4 cookie plugin! /Resources 99 0 R this basic time de lay varies over temperature, and IC manufacturing DIMM is at! Active only when this signal is high Address Map and Register Definitions, 4.6.4.9 of memories... Map and Register Definitions, 4.6.4.9 all pin locations and metal layers they connect, CAS_n & WE_n as. Endobj Sreenivas, Founder, VLSI ddr phy basics Functional Description of the same FPGA or ASIC /resources 87 0 <.