The ddr and ddr2 sdram controllers with altmemphy ip work in conjunction with the altera altmemphy megafunction. In this scenario, double data rate synchronous ram ddr sdram has as. Altmemphy megafunction is an interface between a memory controller and the memory devices, and performs read and write operations to the memory. For example, in a system using one dualrank ddr2 dimm, the memory controller can have up to 18 loads on the address and command pins compared to two for each data pin. Ddr or ddr2 sdram controller, pll, and the example driver. By adjusting the pullup drive strength and pulldown drive strength, the output voltage levels and the rise times can be optimized to find the minimal. Sdram memory can be used as frame buffer for big lcds up to 800x600. The memory controller provides a generic command interface to the users application. The 128mb low power ddr sdram uses a double data rate architecture to achieve highspeed operation. Bitbanging looks workable up to a point with sdram, but at some point the refresh process would take 100% of the mcus time if an sdram controller isnt used and sdram seems to be shortlived.
Ddr sdram many frequently utilized in several application that is embedded indication processing, networking, imagevideo processing etc which need many others cheap and fast memory. The altmemphy megafunction is an interface between a memory controller and the memory devices, and performs read and write operations to the memory. The parameter editor generates a design example, instantiates a phaselocked loop pll, an example driver, your ddr or ddr2 sdram controller custom variation, and an optional delaylocked loop dll for stratix fpga series only. Memory controller an overview sciencedirect topics. This reference design provides an implementation of the ddr memory controller implemented in lattice orca series 4 fpga device. The controllers translate readandwrite requests from the local interface into all the necessary sdram command signals. Designware ddr2ddr sdram memory controller synopsys. Acronym for doubledatarate two, which refers to a computer memory technology as it applies to synchronous dynamic random access memory sdram.
The ddr sdram controller uses a 90o phase shifted system clock to capture read data in the center of the data window. Usage of the new open sourced rbu remote bios update driver. This interface reduces the effort to integrate the module with the remainder of the application and minimizes the need to deal. By 2000, sdram had replaced virtually all other types of dram in modern computers, because of its greater performance. The synopsys designware ddr2ddr sdram memory controller ip mctl offers an efficient digital interface between up to 32 onchip application buses and a ddr2ddr physical layer phy in a ddr2 or ddr memory subsystem. Obtain the data sheet for the ddr sdram chip or dimm used. Sdram controller megacore functiongenerated example driver. The number of socs that require an interface to offchip memory is increasing. It is also known as column address strobe cas latency or simply cl. How can a custom ip readwrite data to ddr2 sdram plb bus. Ti emif sdram controller driver the linux kernel documentation.
For ddr dram subsystem designers who need ddr controller ip, the denali ddr controller ip offers several capabilities to help better manage ddr subsystem such as dram power management. A memory interface device uses a driver impedance adjustment engine with state machine for off chip driver ocd calibration which is used to set the driver voltage levels of the dram memory module or dimm of the jedec ddr ii standard type. Ddr4 delivers higher performance, higher dimm capacities, improved data integrity and lower power consumption. Synchronous tells about the behaviour of the dram type. An17 ddr sdram memory termination some points to keep in mind when working with these values. Scsi devices exist using a transport medium such as usb. For this reason, based on a common standard bus interface, an innovative design of the ddrddr2 sdram compatible controller is implemented and verified. An innovative design of the ddrddr2 sdram compatible.
When we introduced ddr sdram, it was a revolutionary and pioneering technologyenabling applications to transfer data on both the rising and falling edges of the clock signaland vastly improving performance over sdram. In this scenario, double data rate synchronous ram ddr sdram has as main characteristics large capacity to store data, low cost and high bandwidth. The value of the cl is usually expressed in terms of clock cycles. Ddr sdram pointtopoint simulation process technical note. Ddr seems to offer better longevity, but from my reading of ddr specs the timing alone precludes bitbanging its interface. The driver is a selfchecking test generator for the ddr sdram controller. This driver takes care of only lpddr2 memories presently. This paper shows how to design and implement an enhanced memory controller with high performance amba ahblite interface native ddr sdram controller. Standards are defined for the ics as well as the dimms they enable. For the fpga clock output to memory chip clock input, nominal delay, enter. An4039 powerquicc ddr3 sdram controller register setting considerations micron appnotes. Dlls or equivalent circuits actually first appeared in some of the single data rate sdrams in the late 1990s to eliminate some of the clock insertion delay between the clock pin and the data output. The ddr sdram controller has the following special function registers sfrs ddrtsel. Design guidelines for implementing ddr and ddr2 sdram interfaces in cyclone iii devices step 2.
A builtin selftest module is used to generate the data pattern applied to the ddr controller, selecting the memory operation, address range tested and the. Aug, 2008 the number of socs that require an interface to offchip memory is increasing. This application note examines the basics of ddr, provides general boardlevel design guidelines for using the msc711x. The altmemphy megafunction is an interface between a memory controller and the memory devices, and pe rforms read and write operations to the memory. We will cover all of the components in the bo ardlevel skew in detail in the assumptions section of this document. Test ddr or ddr2 sdram interfaces on hardware using intel. Command execution engine the command execution engine is the main component of the ddr sdram controller. Set the register values for the ddr controller registers to match your external ddr memory characteristics. Interfacing ddr3 sdram memory controller to an virtex 6 fpga. The controller will support data widths from 8b to 80b and multiple memory types including components, udimm, sodimm. The 128mb low power ddr sdram is a highspeed cmos, dynamic randomaccess memory containing 4,217,728 bits. On the surface, a ddr sdram component is simply a readwrite memory. This register sets the ddr memory width in the controller.
The ddr and ddr2 sdram controllers handle the complex aspects of using ddr and ddr2 sdraminitializing the memory devices, managing sdram banks, and keeping the devices refreshed at appropriate intervals. As a result, more and more designers are turning to ddr sdram interfaces such as ddr, ddr2, and ddr3 to. Unlike previous technologies, sdram is designed to synchronize itself with the timing of the cpu. Ddr and ddr2 sdram controller with altmemphy ip user. Each of the 33,554,432bit banks is organized as 4,096 rows by 512 columns by 16 bits. It was manufactured by samsung electronics using a cmos complementary metaloxidesemiconductor fabrication process in 1992, and massproduced in 1993. The project also contains a simple push button interface for testing on the dev board. The ddr synchronous dynamic random access memory sdram controller implements the controls for an external memory bus interface using the dual data rate ddr version 2 protocol and electrical interface that adheres to the jedec standard jesd792f nov. Ddr and ddr2 sdram controller with altmemphy ip user guide. Ddr2, ddr3, and ddr4 sdram board design guidelines 4.
Emif is an sdram controller that, based on its revision, supports one or more of ddr2, ddr3, and lpddr2 sdram protocols. The components that make up the boardskew budget have to include isi, vref noise, path length mismatch, crosstalk, cin mismatch, and termination resistor tolerance. The driver uses a state machine to write data patterns to a range of column addresses, within a range of row addresses in all memory banks. This sdram memory chip is connected to sdram bank 2 of flexible memory controller of stm32f429 mcu. This is a very a simple sdram controller which works on the de0 nano. The megawizard plugin manager generates an exam ple toplevel file, consisting of an example driver, and your ddr, ddr2, or ddr3 sdram highperformance. The ddr sdram controller translates read and write requests from the local interface into all the necessary sdram command signals.
This ddr controller is typically implemented in a system between the ddr and the bus master. The first commercial sdram was the samsung km48sl2000 memory chip, which had a capacity of 16 mb. The lattice double data rate ddr3 synchronous dynamic random access memory sdram controller is a generalpurpose memory controller that interfaces with industry standard ddr3 memory devicesmodules compliant with jesd793, ddr3 sdram standard, and provides a generic command interface to user applications. The ddr sdram controller handles the complex aspects of using ddr sdraminitializing the memory devices, managing sdram banks, and keeping the devices refreshed at appropriate intervals. Emif is an sdram controller that, based on its revision, supports one or more of ddr2, ddr3, and lpddr2. The ddr and ddr2 sdram controllers with altmemphy ip and altmemphy.
Design and simulation of ddr3 sdram controller for high. The memory controller equivalent for scsi is, in fact, a usb host controller. The driver then reads back the data from the same locations, and checks that the data. Xperts corner improving ddr sdram efficiency with a. The core also has separate datain and dataout buses at the user interface. The lovehate relationship with ddr sdram controllers.
Memory controller drivers the linux kernel documentation. Ddr3 memory controller users guide literature number. Ddr controller performance continues to be important, more new applications are demanding higher throughput, improved power management and better reliability. Supposing that the external ddr sdram memory is free from errors, writing a data pattern into the external memory and reading it back is used to validate the ddr controller implementation. The component consists of a ddr sdram controller core with configurable options and. Proj29ddrsdramcontroller vlsi projects electronics. The ddr3 sdram transmitted the read data and data strobes are edge aligned. The main function of ddr3 memory controller sdram is used to program and to store a data. Us6807650b2 ddrii driver impedance adjustment control. Over a period of time enhancements in sdram technology led to the introduction of the double data rate ddr sdram, which means that the memory can transfer data both on the positive and negative edge of. Nevertheless, delay sensitive circuits like ddr memory controllers not always can. The glue logic module multiplexes the 256 bit data busses of the dram controller down to the 32 bit data busses of the microblaze mcs.
And because ddr continues to be an ideal choice for many new designs, weve committed to support it for the long term. As a result, more and more designers are turning to ddr sdram interfaces such as ddr, ddr2, and ddr3 to address their. The double data rate ddr synchronous dynamic random access memory sdram controller is a generalpurpose memory controller that interfaces with industry standard ddr sdram. This means that a memory clock is used between the memory controller and the actual dram and all operations are carried out using the same. Ddr sdram modules for desktop computers, dual inline memory modules dimms, have 184 pins as opposed to 168 pins on sdram, or 240 pins on ddr2 sdram, and can be differentiated from sdram dimms by the number of notches ddr sdram has one, sdram has two. Ddr sdram timing parameters and can be changed by the user to suit the ddr sdram memory timings being used thus giving the.
Ddr3 controller working in a spartan xc6slx252i with a 2gb corsair udimm. The new controller enables virtex6 users to capitalize on the improved capacity, performance and power efficiency of the latestgeneration ddr sdram technology. File system memory driver selection guide micrium os. The program ram can be located in the internal for instance sram or external for example ddr sdram memory of the microcontroller. The memory controller is a digital circuit that manages the flow of data going to and from the computers main memory. The msc711x memory controller supports double data rate synchronous dynamic random access memory ddr sdram devices, which are designed to be a high data rate migration path from the standard single data rate sdr memory devices. The ddr latency is the time the memory controller mc must wait between requesting data and the actual delivery of the data. The controller is configurable through the ip catalog. An external memory controller emc module is used into the soc to interface with the ddr memory. Double data rate synchronous dynamic randomaccess memory, officially abbreviated as ddr sdram, is a double data rate ddr synchronous dynamic randomaccess memory sdram class of memory integrated circuits used in computers. The memory controller takes commands individual that is using is local and translates them to your command sequences necessary by ddr sdram devices.
For an example, a dimm with cl3 implies that the memory controller must wait three. Command execution engine the command execution engine is the main component of the. The design example is a fully functional design that can be simulated, synthesized, and used in hardware. The functions of the driver includes reconfiguring ac timing parameters and other settings during frequency, voltage and temperature changes. Ddr sdram controller pipelined lattice semiconductor. Compared with ddr, ddr2 sdram ddr2 has higher speed, lower power, higher efficiency, and higher stability. The northwest logic ddr4 controller core is designed for high memory throughput, high clock rates, and full programmability in computing and networking applications. None of its successors are forward or backward compatible.
Ddr2, ddr3, and ddr4 sdram board design 4 guidelines 2014. The testbench consists of a microblaze mcs microcontroller with one module of glue logic to adapt it to the dram controller. Sdram stm32f429idisco board is equipped with 8mb sdram chip is42s16400j from integrated silicon solution, inc. Instantiate phy and controller in a quartus ii project begin your memory interface design by instantiating the physical layer phy and controller modules. The file system does not provide any driver for such memory. For the ddr sdram controller, the data passes through the controller, and the controller handles all ddr related synchronization and timing generation. Ddr and ddr2 sdram controller with altmemphy intel fpga ip. This enables the memory controller to know the exact clock cycle when the requested data will be ready, so the cpu no longer has to wait between. Ddr sdram referred to as ddr transfers data on both the rising and falling edge of the clock. What is the difference between sdram, ddr1, ddr2, ddr3 and. With ddr3 reaching its limits in a world that demands higher performance and increased bandwidth, a new generation of ddr sdram has arrived. With the rambus ddr4 phy, it comprises a complete ddr4 memory interface subsystem.
Use the rtg4 ddr memory controller configurator to configure the ddr controller, select its datapath bus interface axi or ahb, and select the ddr clock frequency as well as the fabric datapath clock frequency. An4039, powerquicc and qoriq ddr3 sdram controller. Keep the drams simple, put complexity in the controller there are three critical decisions that forever complicated the ddr sdram memory controller. Memory controllers folder, and click either ddr sdram megacore. The xilinx ddr4 core can generate a full controller or phy only for custom controller needs. A memory interface device uses a driver impedance adjustment engine with state machine for off chip driver ocd calibration which is used to set the driver voltage levels of the dram memory module or dimm of the jedec ddrii standard type. Ddr sdram controller ip designed for reuse design and reuse. This interface reduces the effort to integrate the module with the remainder of the application and minimizes the need to deal with. Ddr sdram, also retroactively called ddr1 sdram, has been superseded by ddr2 sdram, ddr3 sdram and ddr4 sdram.
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