Asic implementation of ddr sdram memory controller. Data rate sdram, and you need to refer to the first half of this document sdram memory. A dedicated memory controller is of prime importance in applications that do not contain. The access time for read and the write cycle is optimised based on the cas latency and burst length of the ddr sdram. Host side interface of the controller is availiable in. Ddr sdram memory controller reference design xapp851 v1. Keep the drams simple, put complexity in the controller there are three critical decisions that forever complicated the ddr sdram memory controller. Asic implementation of ddr sdram memory controller abstract. The ddr sdram is an enhancement to the conventional sdram running at bus speed over 75mhz. Asic implementation of ddr sdram memory controller ijedr. Citeseerx design and implementation of ddr sdram controller. The ddr memory controller design for the ddr sdram and the connection between the fpga provides a solution 3.
For the currently the most widely used data storage memory is ddrii sdram which is used in the highspeed, highprecision, and highmemory depth of the data storage and communication system, using ise software and calling the ip core of xilinx to create mcb, adopting the verilog hdl to achieve a common ddrii sdram controller interface for universal design and application based on. The main controller layer consists of the ddr sdram controller state machine and fifo. Asic design methodology is opted for double data rate ddr sdram controller. In this paper, the implementation has been done in verilog hdl by using xilinx ise 9. The ddr sdram controller supports data width of 64 bits and burst length of 4 and cas column address strobe latency of 2 and in this pipelined sram controller design, improvement of 28. In importance in applications that do not contain microprocessors single data rate sdram, the data is transferred on every highend applications. March 2009 altera corporation ddr and ddr2 sdram controller compiler user guide the performance of the entire system and in general the ddr or ddr2 sdram controller depends upon the number of masters and slaves connected to the avalon memorymapped avalonmm interface, which degrades as the number of masters and slaves connected to it. The controller generates command signals and based on these signals the data is either read or written to a particular memory location. Implementation of ddr sdram controller using verilog hdl doi.
Mimas v2 has a xilinx spartan 6 lx9 fpga in csg324 package has two builtin memory controllers and a 512mbit lpddr sdram lp stands for low power and ddr stands for double data rate. There are many researches going on ddr2 sdram controller in the vlsi industry by the. Double data rate originally referred to as simple ddr and it was designed to replace sdram. Now our controller makes the sdram appear as a dualport memory. Design and implementation of sdram controller in fpgas. But an sdram is really a singleport memory, so our controller has to play a trick. Deepali sharma et al, ijcsit international journal of. Introduction to ddr sdram memory controller the ddr sdram uses double data rate architecture to achieve highspeed data transfers. The novelty of this paper is to present the design techniques that lead to high performance memory controllers. Figure 1 is the block diagram of the ddr sdram memory controller that is. The ddr memory controller external signals, depicted in figure 4, are described as follows.
The main control module consists of three sub modules. 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. A ddr memory controller is designed to achieve the high speed bulk data transfer task much faster than the processor 7. The memory controller comes with two implementations of the read capture logic that are optimized for the target fpga family and ensure the best timing margins and. The mobile double data rate ddr sdram controller ip core is designed for use in applications requiring high memory throughput, high clock rates and full programmability. The ddr sdram controller translates read and write requests from the local interface into all the necessary sdram command signals. The double data rate 3 ddr3 sdram memory controller core is designed for use in applications requiring high memory throughput, high clock rates and full programmability. It takes care of row refreshes and gives an easy to use interface for the host logic to access the sdram. Ddr sdram controller core northwest logics double data rate ddr sdram controller core is designed for use in applications requiring high memory throughput, high clock rates and full programmability.
The ddr memory controller supports a 16pin or 32pin data path size. Ddrddr2 sdram is similar in function to regular sdram, but doubles the bandwidth of the memory by transfer ring data twice per cycle, on both the rising and falling edges of the clock signal. The data transition occurs at the both falling edges and rising. The memory controller provides command signals for memory refresh, read and write operation rising edge of the clock whereas in double data rate ddr. The memory controller core provides a generic command interface to the users application.
On the right, the controller drives the sdram signals. The ddr controller design objectives the creation of a con. Ddr 3 sdram memory controller ip core hitech global. This paper analyzes the current international technology trends and storage controller ddr2 sdram controller detailed technical specifications. However variable sdram access latencies pose some challenges for its eective use in.
Beyond ddr sdram memory controller ip core was developed with this trend in mind. The lovehate relationship with ddr sdram controllers love the cheap memory, hate the complex controller by graham allan, mosaid almost everyone knows that the bulk of drams produced end up in desktop and laptop computers just like the one used to write this article. Ddr memory controller design based on fpga scientific. Data rate sdram controller and integrated it with a pro cessor. The xilinx mch opb ddr2 sdram controller is a soft ip. Sdram is preferred in embedded system memory design. This paper exhibits a performance evaluation of ddr4 memory controller using uvm based verification environment, testbench is built to assure that ddr4 memory controller can effectively access the memory transactions from the axi4. Synchronous dynamic randomaccess memory sdram is any dynamic randomaccess memory dram where the operation of its external pin interface is coordinated by an externally supplied clock signal dram integrated circuits ics produced from the early 1970s to early 1990s used an asynchronous interface, in which input control signals have a direct effect on internal functions only.
Improved description for implementing altera memory interface ip chapter. The core also has separate datain and dataout buses at the user interface. Srinivasa rao 1,2,3department of the electronics and communication engineering, nits, hyderabad, ap, india. The core accepts commands using a simple local interface and translates them to the command sequences required by ddr sdram devices. The ddr2 sdram controller with uniphy offers fullrate and halfrate ddr2 interfaces, and the ddr3 sdram controller with uniphy offers a halfrate ddr3 sdram interface. The controller mainly aims the interaction of memory and processor with a goal of well refined memory designs. Ddr sdram transfers data on both the rising and falling edge of the clock. Considering the tight timings of a ddr sdram memory interface, the capture of read data is a critical design aspect of a ddr sdram interface. In this paper, the double data rate sdram controller is implemented using asic methodology. Broadband applications have some different needs and often require analog signal processing. This project implements a ddr ram controller at the rtl level for the altera cyclone ii fpga on a de2 development board. Fpga implementation of a time predictable memory controller.
Axi4 read, write transactions, latency and bandwidth measurements in data less simulation has been performed. This paper deals with the fpgaimplementation of a highspeed interface for ddr sdrams. The lovehate relationship with ddr sdram controllers. Asic implementation of ddr sdram memory controller amit bakshi sudhanshu shekhar tribikram pradhan ratnadip dey school of electronics pandey. Ddr controller performance continues to be important, more new applications are demanding higher throughput, improved power management and better reliability. Ddrii sdram memory controller interface design and. Implementing highspeed doubledata rate ddr sdram controllers on fpga. Design and verification of a dfiaxi ddr4 memory phy bridge. For the currently the most widely used data storage memory is ddrii sdram which is used in the highspeed, highprecision, and high memory depth of the data storage and communication system, using ise software and calling the ip core of xilinx to create mcb, adopting the verilog hdl to achieve a common ddrii sdram controller interface for universal design and application based on. It could operate the external bus twice as fast as its predecessor, giving a major boost to overall system performance.
This article introduces a sdram controller based on fpga. Mobile ddr sdram memory controller ip core for fpga and asic. Implementation of ddr sdram controller using verilog hdl mayuri sanwatsarkar and jagdish nagar department of electronics and communication. To put things in perspective, heres a view of a typical fpga system using our sdram controller.
Graphics double data rate sdram is a type of specialized ddr sdram designed to be used as the main memory of graphics processing units gpus. Moores law1 has benefited from the entire ic implementation flow, from rtl to. The ddr sdram controller architecture is shown in figure 2. Double data rate ddr sdram controller is implemented using cadence rtl compiler. Implementation of physical design in ddr sdram memory. In highend applications, like microprocessors there will be specific built in peripherals to. The work concentrates on the relative study of two memory controllers viz. Xilinx xapp851 ddr sdram controller using virtex5 fpga. Ddr and ddr2 sdram controller with altmemphy ip user. Pdf asic implementation of ddr sdram memory controller. Implementation of ddr sdram controller using verilog hdl. The controller simplifies the sdram command interface to standard system readwrite interface and also optimizes the access time of readwrite cycle. The memory controller will accept memory requests from the cpu, analyze the requests, rearrange them, queue them up, and dispatch them to the sdram in the most efficient manner.
Physical design implementation of 32 bit ddr sdram controller. A general memory controller a general memory controller consists of two parts. This reference design provides an implementation of the ddr memory controller implemented in lattice orca series 4 fpga device. Ipug46 ddrddr2 sdram controller maco cores users guide. If you have a heronfpga9 then it has double data rate sdram and you need to refer to the second half of this document ddr sdram memory. The ddr sdram controller uses a 90o phase shifted system clock to capture read data in the center of the data window. The phy layer consists of me mory initialization logic, and addresscommanddata io. Uvm based verification environment for performance. Apr 29, 2016 mimas v2 has a xilinx spartan 6 lx9 fpga in csg324 package has two builtin memory controllers and a 512mbit lpddr sdram lp stands for low power and ddr stands for double data rate. The main control module state machine is responsible for the initialization of the memory controller. The ddr sdram controller architecture is implemented in verilog hdl.
The host logic can use the sdram more likely an sram because of the controller. Ddr and ddr2 sdram high performance controllers ii. Because the ddr sdram has twice the sdram memory data rate, now has been widely used. There is also a timing analysis about data communication between fpga and sdram before postsimulation. Learning fpga and verilog a beginners guide part 6 ddr. Implementation of ddr sdram memory controller for embedded. Design and implementation of high speed pipelined ddr. Ddr sdram main controller block before it is operational the ddr sdram memory controller shall be initialized with set of parameters. Synchronous dram sdram has become a mainstream memory of choice in design due to its speed. This paper deals with the fpga implementation of a highspeed interface for ddr sdrams. A dedicated memory controller is of prime importance in applications that do not contain microprocessors highend applications. Ddr2 sdram was the second generation of double data rate sdram.
Design and implementation of ddr sdram controller using. Gddr sdram is distinct from commodity types of ddr sdram such as ddr3, although they share some core technologies. It interleaves accesses when possible, maximizing utilization of memory control and data buses. Implementation of fpga based memory controller for ddr2 sdram. The ddr and ddr2 sdram controllers with altmemphy ip work in conjunction with the altera altmemphy megafunction. Sdram has become the major component in vlsi design industry. Data path memory controller memory interface round trip delay xilinx. For the ddr sdram controller, the data passes through the controller, and the controller handles all ddr related synchronization and timing generation. Links to ddrddr2 sdram application notes, reference designs, development boards. This ddr controller is typically implemented in a system between the ddr and the bus master. 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. Ddr sdram referred to as ddr transfers data on both the rising and falling edge of the clock. The memory controller provides command signals for memory refresh, read and write operation and initialization of sdram.
The megawizard interface generates an exam ple toplevel project, consisting of an example driver, and your ddr2 or ddr3 sdram controller custom variation. With the rapid development of electronic science and computer science, the large scale integrated circuit applied in the military, economic and social life is more and more widely. This might not be an exhaustive list of modules and you need to check in the user manual for the. However variable sdram access latencies pose some challenges for its eective use in rts. 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. The access latency or access speed solely depends on the implementation of memory controller.
Design and realization of sdram controller based on fpga. Synopsys design compiler tool is used to obtain the necessary results. Fifo, memory controller, sdram, wishbone bus master. The fpgas csg324 package is important here because xilinx spartan 6 lx9 is available in some other packages that dont have a builtin memory controller. In highend applications, like microprocessors there will be specific built in peripherals to provide the interface to the sdram. The process involves issuing sequence of command signals before it gives access to memory. The ddr 4 controller is typically implemented in a system between the ddr and the bus master. Synchronous dram sdram is preferred in embedded system memory design because of its speed and pipelining capability.
Implementation of fpga based memory controller for ddr2. The project also contains a simple push button interface for testing on the dev board. The auto refresh for the ddr sdram is done by the controller. We can optimize the memory controller in area, power, latency etc. We aim to achieve a performance, in terms of bandwidth, comparable to asic. Over 10 million scientific documents at your fingertips. Ddr controller architecture the ddr controller contains the logic used to control data accesses and the physical elements used to interface with the external memory. Soc, asic, or fpga designs are comprised of ddr memory controller, ddr phy, userlogic. Architecture of ddr sdram controller ddr sdram controller module receives addresses and control signals from the bus master. The development trend in ddr sdram devices is biased towards higher clock frequencies and higher latencies. Ddr2 sdram memory controller can be used in many other applications such as image processing, video processing etc.
Through board verification, a burst mode with auto precharge and fullpage mode without auto precharge are achieved and the highest bandwidth in each. We aim to achieve a performance, in terms of bandwidth, comparable to asic implementations. A pcb board was also designed and fabricated to provide an interface between the fpga and the memory chip. It describes the architecture of controller and takes explain for each module. The synchronous dynamic random access memory sdram is widely used external memory because of its attractive combination of high capacity, low cost and competitive performance. Implementation of ddr sdram memory controller for embedded soc.
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