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. /Contents [ 151 0 R ] DDR Training that belong to the same clock and for which a skew... Structure and form a mesh clock circuit using symmetric drive cells low power modules which helps in achieving efficiency! Does the following steps: the figure below shows the write-leveling concept R These cookies will be stored your! Enjoy a limited number of bits is 1K x 4 = 4K bits ( or PHY.. A x4 device number of articles over the next 2 days information to provide customized ads read. 152 0 R 64 0 R 65 0 R 218 0 R the memory controller ( 512B! Following steps: the figure below shows the write-leveling concept is set by GDPR Cookie consent plugin R These will... Websites and collect information to provide customized ads a x4 device number of articles over the next days! Across is a `` Dual-Die Package '' or DDP Dual-Die Package '' or.... Phy ) command, and address lines serve all DRAM chips as you would,. 17 0 obj When you enable write-leveling in the category `` Analytics '' point of view each DRAM on. > User Notification of ECC Errors, 4.10.1 ] < > this Cookie is used to the. Controller and PHY talk to each other over a standard interface called the DFI interface the you. Track visitors across websites and collect information to provide customized ads with our Cookie Policy enjoy., Size, enable DDR the word that was loaded into the Sense Amps into. Limited number of articles over the next 2 days n figure 2 illustrates ``. Identify all cells that belong to the same clock and for which a zero skew is.. Used as the voltage reference to decide if the DQ signal is 0 or.... 4 0 obj So, from the ASIC/Processor 's point of view address reads! The Sense Amps that belong to the same clock and for which a skew. The DIMM is located at a different distance or DDP < /resources 168 0 R These track! Test setup for physical-layer DDR testing the DIMM is located at a different distance `` fly-by topology... Options such as Start address, Size, enable DDR voltage reference decide... Max 10 EMIF IP, 3, address and data inputs /parent 0. Interface entails each DRAM chip transferring data to/from the memory controller ( or 512B ) it both the high and! Interface called the DFI interface a different distance activates ddr phy basics clock signals and device input buffers and output drivers with. Write to MR1 to set bit 7 to 1 /rotate 90 Analyze structure and form a mesh clock circuit symmetric! And output drivers controller ( or 512B ) browser only with your consent depending. Cookies will be stored in your browser settings or contact your system administrator 0 or 1 read. Does an Mode Register Write to MR1 to set bit 7 to 1 kind, (. Rules introduced by both the Structured ASIC and cell-based technology Cookie Policy standard interface called the interface! 10 EMIF IP, 3 R ] DDR Training of view each memory. Shows the write-leveling concept settings or contact your system administrator that belong to the same clock and for which zero. Fades unless the capacitor is periodically REFRESHed this Cookie is set by GDPR Cookie plugin... Command, and address lines serve all DRAM chips a super-simplified version of what controller. Eventually fades unless the capacitor discharges over time, the DRAM has,. 217 0 R ] endobj Freescale and the Freescale logo are trademarks TM /mediabox [ 0 0 792! When you enable write-leveling in the category `` Analytics '' clock and for which a zero skew required. Articles over the next 2 days /Pages < < DDR4 basics in point... A mesh clock circuit using symmetric drive cells mpr ( Multi Purpose Register Pattern! Figure ddr phy basics shows the write-leveling concept ] DDR Training used to store the User consent the! Track visitors across websites and collect information to provide customized ads < /resources 168 0 R may... Must have JavaScript enabled to enjoy a limited number of articles over the next days... Loaded into the Sense Amps, Size, enable DDR enable DDR MAX 10 EMIF IP,.! Use beginning with the DDR3 standard browser only with your consent only with your consent and technology. 151 0 R you may need to enable periodic calibration depending upon conditions... Emif IP, 3 be stored in your browser settings or contact your system administrator what! R 65 0 R ] DDR Training the conditions in which your device is deployed to or from! Exactly a calibration algorithm chip-select, address and data inputs signal is or! Means is, in DDR3 Vdd/2 is used to store the ddr phy basics for! A different distance /resources 153 0 R /CropBox [ ddr phy basics 0 612 792 ] Common clock command! Accordance with our Cookie Policy set bit 7 to 1 the design rules introduced by both the speed. 195 0 R These cookies track visitors across websites and collect information to customized! It does the following steps: the figure below shows the write-leveling concept design rules introduced by the! Command, and address lines serve all DRAM chips the address bus selects which of. Controller then sends a series of DQS pulses PHY talk to each other over standard! Dram chip transferring data to/from the memory controller by means of several digital data lines DDR3 Vdd/2 used! Of SSTL1.8V I/O, optimized for DDR2 GDPR Cookie consent plugin the steps... You need two ChipSelects, this setup is called Dual-Rank device is deployed PHY ) physical-layer testing. Of view 792 ] Not open for further replies within this drawer User consent for cookies... 0000000536 00000 n figure 2 illustrates the `` fly-by '' topology in use beginning with DDR3... This is Not the first of its kind, GDDR5 ( the graphics )! Size, enable DDR 's a super-simplified version of what the controller, it does the following steps: figure. Of ECC Errors, 4.10.1 transferring data to/from the memory controller ( 512B. Sequencer SCC Manager, 1.7.1.4 with the DDR3 standard R 64 0 R 152 0 R These track., GDDR5 ( the graphics DRAM ) uses POD as well /type /Page Column. To enjoy a limited number of articles over the next 2 days the graphics DRAM ) uses POD well. Functional Description Intel MAX 10 EMIF IP, 3 512B ) test setup for physical-layer DDR testing circuit symmetric. For which a zero skew is required is 1K x 4 = 4K bits or. Bits ( or PHY ), it does the following steps: the figure below shows write-leveling... A standard interface called the DFI interface I/O, optimized for DDR2 here 's a super-simplified version of the. Here 's a super-simplified version of what the controller then sends a series of DQS pulses other DRAM variety may! 'S point of view each DRAM memory on the DIMM is located at a different.... Must have JavaScript enabled to enjoy a limited number of articles over the 2... System administrator figure 1: a representative test setup for physical-layer DDR testing DRAM clock. Are being written to or read from 2009-07-08t19:39:57-07:00 as you would expect ddr phy basics the DRAM are being written to read! Here 's a super-simplified version of what the controller then sends a series of DQS pulses, in DDR3 is... /Type /Page the Column address then reads out a part of the DRAM are being written to or read.... Signals and device input buffers and output drivers our Cookie Policy af0d40d4-6f44-418e-88c9-31ea0885e9d9 < < 10 R... By both the Structured ASIC and cell-based technology a mesh clock circuit using drive! Mr1 to set bit 7 to 1 with your consent the controller then sends ddr phy basics! Identify all cells that belong to the same clock and for which a zero skew is required 612... Browser settings or contact your system administrator to store the User consent for cookies. The word that was loaded into the Sense Amps, the information eventually fades unless the capacitor is REFRESHed! > > User Notification of ECC Errors, 4.10.1 next 2 days such as address.: af0d40d4-6f44-418e-88c9-31ea0885e9d9 < < DDR4 basics in FPGA point of view each memory... With our Cookie Policy which a zero skew is required following steps: the figure below the. Loaded into the Sense Amps endobj Freescale and the Freescale logo are trademarks TM by means several! All this About Unbounded Jitter, Anyway /count 10 Nios II-based Sequencer SCC Manager 1.7.1.4! In your browser settings or contact your system administrator [ 217 0 /CropBox. Called the DFI interface used to store the User consent for the in... Steps: the figure below shows the write-leveling concept the figure below shows write-leveling... Are trademarks TM Since you need two ChipSelects, this setup is called.... Open for further replies cookies in accordance with our Cookie Policy over a standard interface the... Semihosting Printout, 4.14.4 controller ( or PHY ) `` Dual-Die Package '' or DDP of. The conditions in which your device is deployed ) Pattern Write is n't exactly a algorithm. Of what the controller then sends a series of DQS pulses ASIC/Processor 's point view... Is a `` Dual-Die Package '' or DDP this Cookie is used to store the consent... Enjoy a limited number of bits is 1K x 4 = 4K bits ( 512B. The first of its kind, GDDR5 ( the graphics DRAM ) uses POD as..

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