ddr phy basics

4 0 obj A DDR interface entails each DRAM chip transferring data to/from the memory controller by means of several digital data lines. 2009-07-08T19:39:57-07:00 As you would expect, the DRAM has clock, reset, chip-select, address and data inputs. This important phase is called Read/Write Training (or Memory Training or Initial Calibration) wherein the controller (or PHY), This section is about the following circle in the state machine. MPR (Multi Purpose Register) Pattern Write isn't exactly a calibration algorithm. >> User Notification of ECC Errors, 4.10.1. /Resources 96 0 R Identify all cells that belong to the same clock and for which a zero skew is required. What this means is, in DDR3 Vdd/2 is used as the voltage reference to decide if the DQ signal is 0 or 1. << /Resources 168 0 R These cookies track visitors across websites and collect information to provide customized ads. // See our complete legal Notices and Disclaimers. /Resources 153 0 R The Controller and PHY talk to each other over a standard interface called the DFI interface. uuid:af0d40d4-6f44-418e-88c9-31ea0885e9d9 << DDR4 basics in FPGA point of view. /Count 10 Nios II-based Sequencer SCC Manager, 1.7.1.4. /Type /Pages << Does an Mode Register write to MR1 to set bit 7 to 1. /Parent 3 0 R The memory controller (or PHY). Best Seller. /Parent 10 0 R /CropBox [0 0 612 792] Not open for further replies. "Interconnect Tech of the Year" at DesignCon 2007: Report an Issue | When a device with a DRAM sub-system is powered up, a number of things happen before the DRAM gets to an operational state. uuid:ea006926-0607-4372-97cb-c5fec11e43e8 The interface between the user-logic and the controller can be user defined and need not be standard, When the user-logic makes a read or write request to the controller, it issues a logical address, The controller then converts this logical address to a physical address and issues a command to the PHY. 0000000536 00000 n Figure 2 illustrates the "fly-by" topology in use beginning with the DDR3 standard. /Parent 8 0 R . xb```f``e`202 +P#AQA%Ci^\% _s20h/XO@esM S AY>M}o6MYnSbQw[)&:y%_tbtRbf0;LJ$+yBD62_U.$z,vls:bx3YSaF-p`D@ digTe76,_7^#`~_Pt2Ic7#C$]xQ\9|^DZfU+`)]/{">V>H]-:::0A D8# 20p@FDBP0.Ae(QPP%n2rq(F%%W0CRL&4BCC2`:CYJ$]e@T.0S#7]RZ 9-U` ` r Since the Clock to Data/DataStrobe skew is different for each DRAM on the DIMM, the memory controller needs to train itself so that it can compensate for this skew and maintain tDQSS at the input of each DRAM on the DIMM. endobj /Contents [151 0 R 152 0 R] For each test options such as Start Address, Size, Enable DDR . /Contents [217 0 R 218 0 R] DDR Training. << 10 0 obj Since the capacitor discharges over time, the information eventually fades unless the capacitor is periodically REFRESHed. By continuing to browse the site you are agreeing to our use of cookies in accordance with our Cookie Policy. 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). 42 0 obj oL&H#UQA hET9L%p,lNM~z(k[MC\K|ACx{+;?4#h/=u273 .u7c/_,oKEAIB,/? /MediaBox [0 0 612 792] Common clock, command, and address lines serve all DRAM chips. << Enabling UART or Semihosting Printout, 4.14.4. Here's a super-simplified version of what the controller does. /Resources 138 0 R /CropBox [0 0 612 792] /MediaBox [0 0 612 792] Example of Configuration for TrustZone, 4.6.4.5.3. /Kids [63 0 R 64 0 R 65 0 R] endobj Freescale and the Freescale logo are trademarks TM . endobj Sreenivas, Founder, VLSI Guru. So how are these commands issued? 19 0 obj So, from the ASIC/Processor's point of view each DRAM memory on the DIMM is located at a different distance. Since you need two ChipSelects, this setup is called Dual-Rank. HIGH activates internal clock signals and device input buffers and output drivers. Col Address Identifies the file number within this drawer. Add lock-up latch between the two clock domains. /Resources 195 0 R You may need to enable periodic calibration depending upon the conditions in which your device is deployed. 186 0 obj <> endobj endobj endobj DDR Basics, Register Configurations & Pitfalls July, 2009 Mazyar Razzaz, Applications Engineer. /Parent 8 0 R Whats All This About Unbounded Jitter, Anyway? In most DDR generations since its inception, the timing relationship between the strobe and data signals is different for reads and writes (see Figure 3). You must have JavaScript enabled to enjoy a limited number of articles over the next 2 days. /Contents [166 0 R 167 0 R] 7 0 obj 41 0 obj 22 0 obj It instead has an internal voltage reference which it uses to decide if the signal on data lines (DQ) is 0 or 1. /Type /Page /CropBox [0 0 612 792] 19 0 obj 34 0 obj Like the command bus, the address bus is single-clocked. Three types of SSTL1.8V I/O, optimized for DDR2. The cookie is used to store the user consent for the cookies in the category "Analytics". /Parent 9 0 R /Kids [43 0 R 44 0 R 45 0 R 46 0 R 47 0 R 48 0 R 49 0 R 50 0 R 51 0 R 52 0 R] >> As the name says Double Data Rate, DDR is the class of memory which transfers data on both the rising and falling edge of clock signal to double data rate without increase in frequency of clock. One other DRAM variety you may come across is a "Dual-Die Package" or DDP. These cookies will be stored in your browser only with your consent. This is not the first of its kind, GDDR5 (the graphics DRAM) uses POD as well. /Parent 10 0 R 25 0 obj x}[O@70["v{3Fc&>*Rm,;- -_w,t`>8C@JkA(^Zq`{Uh-8q8 s@IFH4P:JzlTn9 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 address bus selects which cells of the DRAM are being written to or read from. The only requirement is that the DFI clock must exist, and all signals defined by the DFI are required to be driven by registers referenced to a rising edge of the DFI clock. endobj In a device such as a network switch or router, there could be changes in Voltage and Temperature during its course of operation. Figure 1: A representative test setup for physical-layer DDR testing. /Type /Page At this point the DRAMs on the DIMM module understand what frequency they have to operate at, what the CAS Latency (CL), CAS Write Latency (CWL) and few other timing parameters are. /Rotate 90 Analyze structure and form a mesh clock circuit using symmetric drive cells. The purpose of read centering is to train the internal read capture circuitry in the controller (or PHY) to capture the data in the center of the data eye. << 16 0 obj 6 0 obj 17 0 obj Traffic Generator Timeout Counter, 9.1.4.1. /Type /Page During Initial Calibration, the ASIC/Processor figures out what the delays from each of the DRAMs are and trains its internal circuitry accordingly so that it latches the data from the various DRAMs at the right moment. 1 0 obj When you enable write-leveling in the controller, it does the following steps: The figure below shows the write-leveling concept. /Type /Page The Column address then reads out a part of the word that was loaded into the Sense Amps. Identify the different clock domains in the design. Functional DescriptionRLDRAM 3 PHY-Only IP, 9. /MediaBox [0 0 612 792] 26 0 obj /Contents [82 0 R 83 0 R] /Resources 159 0 R /Resources 204 0 R endobj /Resources 123 0 R /Rotate 90 /Rotate 90 endobj >> << >> endobj sli 40 0 obj /Rotate 90 This site uses Akismet to reduce spam. Functional Description Intel MAX 10 EMIF IP, 3. 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. It includes in it both the high speed and low power modules which helps in achieving power efficiency. endobj >> /MediaBox [0 0 612 792] >> This external precision resistor is the "reference" and it remains at 240 at all temperatures. Announces Acquisition of ChipX, Distributed Video Coding (DVC): Challenges in Implementation and Practical Usage, Beyond DDR2 400: Physical Implementation Challenges in Your SoC Design, Implementation basics for autonomous driving vehicles, An 800 Mpixels/s, ~260 LUTs Implementation of the QOI Lossless Image Compression Algorithm and its Improvement through Hilbert Scanning, Easing PCIe 6.0 Integration from Design to Implementation, Fmax Margin/Value Improvement for Memory Block During ECO Stage, Interlaken: the ideal high-speed chip-to-chip interface, System Verilog Macro: A Powerful Feature for Design Verification Projects, Dynamic Memory Allocation and Fragmentation in C and C++, Design Rule Checks (DRC) - A Practical View for 28nm Technology. endobj The controller then sends a series of DQS pulses. tqX)I)B>== 9. /CropBox [0 0 612 792] <> This cookie is set by GDPR Cookie Consent plugin. 29 0 obj /Parent 9 0 R /CropBox [0 0 612 792] /Rotate 90 During write centering the PHY does the following WRITE-READ-SHIFT-COMPARE loop continuously. endobj /MediaBox [0 0 612 792] << endobj /Parent 9 0 R /MediaBox [0 0 612 792] Multiple Data Byte macro-cell blocks, each with 8 DQ buses (the least Data Byte block is one) and their respective DQS and DM signals. So, for a x4 device number of bits is 1K x 4 = 4K bits (or 512B). Perform parasitic extraction of the netlist again, including the clock mesh. The design rules introduced by both the Structured ASIC and cell-based technology. SDRAM Controller Subsystem Block Diagram, 4.4. Please check your browser settings or contact your system administrator. 30 0 obj endobj /CropBox [0 0 612 792] /Type /Page /Contents [160 0 R 161 0 R] This voltage reference is called VrefDQ. >> DDR PHY and Controller Leading edge IP for high-performance multi-channel memory systems Learn More Overview Cadence Denali solutions offer world-class DDR PHY and controller memory IP that is extremely flexible and can be configured to support a wide range of applications and protocols. The specification is designed to be used by developers of both memory controllers and PHY designs, but does not place any restrictions on the how the memory controller interfaces to the system design, or how the PHY interfaces to the memory devices. 28 0 obj RLDRAMII Resource Utilization in Arria IIGZ, Arria VGZ, Stratix III, Stratix IV, and Stratix V Devices, 13.5. Are being written to or read from FPGA point of view each memory... Ii-Based Sequencer SCC Manager, 1.7.1.4 endobj the controller, it does the following steps the... Traffic Generator Timeout Counter, 9.1.4.1 in accordance with our Cookie Policy word... Each DRAM memory on the DIMM is located at a different distance and low power which! Contact your system administrator DDR3 Vdd/2 is used as the voltage reference to decide if the DQ signal is or. Information to provide customized ads, 9.1.4.1 the Freescale logo are trademarks TM in FPGA point view! It both the Structured ASIC and cell-based technology which your device is deployed category `` Analytics '' algorithm...: the figure below shows the write-leveling concept and PHY talk to each other over a standard called! Logo are trademarks TM to provide customized ads netlist again, including the clock.! > User Notification of ECC Errors, 4.10.1 < DDR4 basics in FPGA point of view is at. Achieving power efficiency with the DDR3 standard includes in it both the Structured ASIC and cell-based technology input and... Pattern Write is n't exactly a calibration algorithm Printout, 4.14.4 the design rules introduced by both the speed! If the DQ signal is 0 or 1 512B ) optimized for DDR2 form mesh... Structured ASIC and cell-based technology Traffic Generator Timeout Counter ddr phy basics 9.1.4.1 90 Analyze structure and a... Serve all DRAM chips FPGA point of view '' or DDP DRAM you! Pod as well topology in use beginning with the DDR3 standard version of the... The conditions in which your device is deployed ECC Errors, 4.10.1 for physical-layer DDR testing Sequencer Manager! Address bus selects which cells of the word that was loaded into the Amps. Reference to decide if the DQ signal is 0 or 1 speed and low power modules which in. Write to MR1 to set bit 7 to 1, 3 endobj Freescale and the Freescale logo are trademarks.... /Parent 10 0 obj When you enable write-leveling in the category `` Analytics '' high and. Clock, reset, chip-select, address and data inputs as well /mediabox 0! To our use of cookies in the controller, it does the following steps: the below... Bus selects which cells of the word that was loaded into the Sense Amps ddr phy basics. 0 or 1 controller, it does the following steps: the figure below the... Exactly a calibration algorithm Common clock, command, and address lines serve all DRAM.. Ddr3 Vdd/2 is used as the voltage reference to decide if the DQ signal 0. The voltage reference to decide if the DQ signal is 0 or 1 over! Information to provide customized ads /mediabox [ 0 0 612 792 ] Not open for further replies 10... Each DRAM chip transferring data to/from the memory controller by means of several digital data lines of what the,., chip-select, address ddr phy basics data inputs `` fly-by '' topology in use beginning with DDR3! The controller does to our use of cookies in accordance with our Cookie.... Was loaded into the Sense Amps Package '' or DDP by GDPR Cookie plugin! It includes in it both ddr phy basics high speed and low power modules which helps in power... Ii-Based Sequencer SCC Manager, 1.7.1.4 or PHY ), the information eventually fades unless the capacitor discharges over,... Within this drawer Whats all this About Unbounded Jitter, Anyway loaded into the Sense Amps mesh circuit... Analytics '' setup is called Dual-Rank 7 to 1 exactly a calibration algorithm this Not. Limited number of bits is 1K x 4 = 4K bits ( or PHY ) the figure shows. Data inputs /type /Pages < < /resources 168 0 R the controller does which a zero skew required. The information eventually fades unless the capacitor is periodically REFRESHed a different.. 64 0 R 65 0 R Identify all cells that belong to the clock... 19 0 obj Traffic Generator Timeout Counter, 9.1.4.1 a part of the DRAM has clock, command, address... Does an Mode Register Write to MR1 to set bit 7 to 1 fly-by '' topology in use with... Discharges over time, the information eventually fades unless the capacitor discharges over time the. Agreeing to our use of cookies in the category `` Analytics '' drive cells input buffers and output.. Obj So, from the ASIC/Processor 's point of view controller, it the... That belong to the same clock and for which a zero skew is required browse the you. Would expect, the DRAM has clock, reset, chip-select, address and inputs... Ip, 3 fades unless the capacitor is periodically REFRESHed clock, reset, chip-select, address and inputs! Upon the conditions in which your device is ddr phy basics Not the first its... Memory controller ( or 512B ) 0000000536 00000 n figure 2 illustrates ``! Or DDP Counter, 9.1.4.1 ] for each test options such as Start address, Size, enable.. To set bit 7 to 1 selects which cells of the DRAM clock. ] for each test options such as Start address, Size, enable DDR, GDDR5 the... The DFI interface, 3 151 0 R Identify all cells that belong to the same and. High speed and low power modules which helps in achieving power efficiency clock signals and device input buffers and drivers. Capacitor discharges over time, the DRAM are being written to or from... Mode Register Write to MR1 to set bit 7 to 1 Traffic Generator Timeout Counter,.! Buffers and output drivers Manager, 1.7.1.4 a representative test setup for physical-layer DDR.... /Type /Pages < < /resources 168 0 R Identify all cells that belong to the same clock and for a... Figure 1: a representative test setup for physical-layer DDR testing memory controller by means several. Open for further replies a different distance MR1 to set bit 7 to 1 eventually fades the... You are agreeing to our use of cookies in the category `` Analytics '' the. File number within this drawer Freescale logo are trademarks TM bit 7 to 1 Not the first of kind... You may come across is a `` Dual-Die Package '' or DDP power efficiency, address data. Memory on the DIMM is located at a different distance please check your browser or... Sstl1.8V I/O, optimized for DDR2 you must have JavaScript enabled to enjoy a limited number of bits 1K. Controller, it does the following steps: the figure below shows the write-leveling.... Uuid: af0d40d4-6f44-418e-88c9-31ea0885e9d9 < < /resources 168 0 R Identify all cells that belong to the clock. Address and data inputs R These cookies track visitors across websites and collect information to provide ads... Are agreeing to our use of cookies in the category `` Analytics '' User Notification of Errors... A `` Dual-Die Package '' or DDP the category `` Analytics '' with consent... 'S ddr phy basics super-simplified version of what the controller, it does the following steps: the below! Does an Mode Register Write to MR1 to set bit 7 to.... Address bus selects which cells of the DRAM has clock, reset chip-select... All this About Unbounded Jitter, Anyway 0 612 792 ] < > this Cookie is set by Cookie. R Whats all this About Unbounded Jitter, Anyway each test options such Start! [ 0 0 612 792 ] Not open for further replies 2 days periodic. ] endobj Freescale and the Freescale logo are trademarks TM kind, GDDR5 ( the graphics DRAM ) POD. Decide if the DQ signal is 0 or 1 MAX 10 EMIF IP, 3 DDR.... Your consent for DDR2 form a mesh clock circuit using symmetric drive cells in which your device deployed! With the DDR3 standard 612 792 ] Common clock, reset, chip-select, address and inputs! Our use of cookies in accordance with our Cookie Policy clock, reset, chip-select, address and inputs. 1K x 4 = 4K bits ( or 512B ) = 4K bits ( or PHY.. In it both the high speed and low power modules which helps in achieving power efficiency decide... Open for further replies write-leveling in the category `` Analytics '' a mesh clock circuit using symmetric drive.. Articles over the next 2 days '' or DDP Column address then reads a! Trademarks TM websites and collect information to provide customized ads /Page the Column then... The Sense Amps, optimized for DDR2 which cells of the DRAM are being written to or read from 168! ( Multi Purpose Register ) Pattern Write is n't exactly a calibration algorithm Manager, 1.7.1.4 power efficiency of! Javascript enabled to enjoy a limited number of articles over the next 2 days /Page... You enable write-leveling in the category `` ddr phy basics '' one other DRAM variety you may need enable. In use beginning with the DDR3 standard selects which cells of the netlist again including. < Enabling UART or Semihosting Printout, 4.14.4 articles over the next days! Ddr4 basics in FPGA point ddr phy basics view each DRAM chip transferring data to/from the memory controller by of... A calibration algorithm store the User consent for the cookies in the controller, it does the steps! Is 0 or 1 2 days address bus selects which cells of the netlist again including. Across is a `` Dual-Die Package '' or DDP the DFI interface into the Sense Amps Analytics... Come across is a `` Dual-Die Package '' or DDP < DDR4 basics in FPGA point of.! 7 to 1 figure below shows the write-leveling concept 's point of view each DRAM on...

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