Nasic implementation of ddr sdram memory controller pdf merger

Double data rate originally referred to as simple ddr and it was designed to replace sdram. The designware basic universal ddr controllers consist of the universal ddr protocol controller and the universal ddr memory controller, which support the jedec ddr3, ddr2, mobile ddr, lpddr2, and lpddr3 sdram standards. Design and simulation of ddr3 sdram controller for high. Synchronous dram sdram is preferred in embedded system memory design because of its speed and pipelining capability. Ddr sdram timing parameters and can be changed by the user to suit the ddr sdram memory timings being used thus giving the. 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. Design and implementation of high performance ddr3.

The controller generates command signals and based on these signals the data is either read or written to a particular memory location. Asic implementation of ddr sdram memory controller amit bakshi school of electronics engineering. This module gives you a block diagram overview of the memory controller as well as the basic operation and finishes with an in depth look at the registers. Ddr sdram referred to as ddr transfers data on both the rising and falling edge of the clock. Design and implementation of high speed pipelined ddr sdram. Second generation of ddr memory ddr2 scales to higher clock. Ddr 3 sdram memory controller ip core hitech global. The project also contains a simple push button interface for testing on the dev board. A memory controller consists of a refresh circuit and a digital circuitry that controls the data flow to and from the memory. Mch opb double data rate ddr synchronous dram sdram controller 6.

Designware basic universal ddr memory and protocol. The ddr sdram controller architecture is shown in figure 2. Each bank of memory has its own independent base address and address range. The basic functional block diagram of ddr sdram controller shown in fig. Links to ddrddr2 sdram application notes, reference designs, development boards. The main function of ddr3 memory controller sdram is used to program and to store a data. Sdram generations offers high performance and bandwidth. Ddr sdram transfers data on both the rising and falling edge of the clock. Ddr sdram offers over the previous standard dram memory sdr single data rate sdram, is that data is clocked on both edges of the synchronous clock that is shared between the mpu and the ddr sdram.

To further organize the data transfer memory controllers are designed. Xilinx ug388 spartan6 fpga memory controller user guide. This is a very a simple sdram controller which works on the de0 nano. Cortexm3 processor, up to 512 kb of envm, 64 kb of esram, and memory interfaces for ddrsdr sdram for program code, and data.

Ddr controller provides a synchronous command interface to the ddr sdram memory along with several control signals. 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. However, in distinction from conventional techniques, the initial delay determined by the dll is fine tuned with an offset determined by a memory test. The designed ddr controller supports data width of 64 bits, burst length of 4 and cas column address strobe latency of 2. In this paper, the overall architecture of the ddr4 sdram controller is proposed. To implement an mcb based memory interface, one of the two. Sdram synchronous dram, ddr double data rate sdram, ddr2 double data rate 2 sdram, and ddr3 double data rate 3 sdram. Improved description for implementing altera memory interface ip chapter. The controllers translate readandwrite requests from the local interface into all the necessary sdram command signals. The double data rate ddr synchronous dynamic random access memory sdram controller is a generalpurpose memory controller that interfaces with industry standard ddr sdram. Thus ddr2 sdram has higher speed, density and low power consumption then ddr sdram. The memory controller block mcb is a dedicated embedded multiport memory controller.

Ddr sdram architecture, which became highly success ful and was. The core accepts commands using a simple local interface and translates them to the command sequences required by ddr3 sdram devices. 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. The access latency or access speed solely depends on the implementation of memory controller. Synchronous dram sdram has become a mainstream memory of choice in design due to its speed. Coreddr ddr sdram controller product summary intended use ddr sdram controller for standard sdram chips and dimms key features interfaces to external ram supports up to 1024 mb of memory synchronous interface highperformance access logic allows cascading of read and write requests enabling up to 100% throughput. The ddr sdram interface signals are the same for all core con.

The work concentrates on the relative study of two memory controllers viz. The execution unit can be clocked at a first clock rate, whereas the memory controller can be selectively clocked at either the first clock rate or a second clock rate that. However most of the operations of sdr sdram and ddr sdram controller are same, but in case of ddr sdram controller we need to modify some features since it uses double data rate architecture. The altmemphy megafunction is an interface between a memory controller and the memory devices, and performs read and write operations to the memory. Xilinx xapp496 creating wider memory interfaces using. Implementation of ddr sdram controller using verilog hdl. Ddr sdram controller pipelined lattice semiconductor.

The result is a potential doubling of the bandwidth between the mpu and the ddr sdram. Pdf asic implementation of ddr sdram memory controller. Double data rate ddr memory controllers are used to drive ddr sdram, where data is transferred on both rising and falling edges of the systems memory clock. The xilinx mch opb ddr2 sdram controller is a soft ip. Implementation of fpga based memory controller for ddr2. Ddrsdram layout considerations for mcf547x8x processors. This paper analyzes the current international technology trends and storage controller ddr2 sdram controller detailed technical specifications. 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. For better throughput and speed, the controllers are to be designed with clock. Ddr and ddr2 sdram controllers with altmemphy ip user guide 1. Because the ddr sdram has twice the sdram memory data rate, now has been widely used. The controller mainly aims the interaction of memory and processor with a goal of well refined memory designs. These steps are followed before the controller issues the commands to the memory. Ddr memory controllers are significantly more complicated when compared to single data rate controllers citation needed, but they allow for twice the data to be transferred without increasing the.

Tms320c674xomapl1xprocessor ddr2mddr memory controller. Sdram controller user programmable machine for other types both local and 60x bus use the memory controller multiple parity options available features the memory controller consists of three types of interface generation. Pdf the design and simulation of a 400533mbps ddrii sdram. 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.

Implementation of fpga based memory controller for ddr2 sdram. Implementation methodolody the ddr sdram controller architecture is implemented using verilog hdl. As shown in the architecture block diagram of figure 21, page 16, the mcb has two basic. The chip density of ddr sdram is 1 gb and that of ddr2 sdram is 4 gb. This interface reduces the effort to integrate the module with the remainder of the. Chapter 5 implementation of the customizable architecture of. The ddr sdram controller supports data width of 64 bits and.

As we use a single port memory controller, we need a channel merger block to merge both. Ahb interfaced high speed ddr sdram memory controller. We propose to merge the write and the refresh operations to. Data rate sdram controller and integrated it with a pro cessor. The command logic block generates a readwrite command. The lovehate relationship with ddr sdram controllers. In addition, this volume includes basic information for various memory. The core also has separate datain and dataout buses at the user interface. Sdram controllers with altmemphy ip offer the highperformance controller ii. As much as possible, we want to make it easy to modify the board and the memory controller to migrate from the ddr2 implementation to ddr3.

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. Presentation provides both a starter introduction to what dram is and how it operat. The data bus transfers data on both rising and falling edge of the clock ddr sdram. An sdram controller specifically for providing the correct memory control signals, connections, and timing for sdram devices.

The function of each emc pin for static memory, sdr sdram and ddr sdram is shown in. Ddr sdram interface bus signals burst type burst type. Asic implementation of ddr sdram memory controller. 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. Dram refresh mechanisms, penalties, and tradeoffs engineering. The cortexm3 processor has a predefined memory map for code space, data space, and system space. Ddr3 memory controller users guide literature number.

Ddr memory controller design based on fpga scientific. Hardware and layout design considerations for ddr3 sdram. 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 ddr and ddr2 sdram controllers with altmemphy ip work in conjunction with the altera altmemphy megafunction.

Pdf refreshaware ddr3 barrel memory controller with. 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. Implementation of physical design in ddr sdram memory. Memory design considerations when migrating to ddr3. The designed ddr controller generates the control signals as synchronous command interface between the dram memory and other modules. 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. Deepali sharma et al, ijcsit international journal of. Pdf nowadays, ddr sdram double data rate synchronous dynamic random access memory has become the most popular class of memory used in. Introduction to ddr sdram memory controller the ddr sdram uses double data rate architecture to achieve highspeed data transfers.

This memory device provides higher reliability, availability and serviceability than other ddr memories. 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. Implementation figure 1 represents the basic block diagram of ddr2 sdram. The ddr memory controller design for the ddr sdram and the connection between the fpga provides a solution 3. R ddr sdram interface design ddr sdram controller interface figure 4 presents the state machine of the ddr sdram command generation state machine. Ddr2mddr memory controller 1 introduction this document describes the ddr2mobile ddr memory controller.

For ddr4, lpddr4 and more advanced features, see the enhanced universal ddr memory controller umctl2. Rom and basic devices only requiring a chip select. 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. Implementation of ddr sdram memory controller for embedded soc. Memory replacement instructions for the network processing engine or network services engine and inputoutput controller ol835804 chapter 2 sdram and dram memory systems overview terms and acronyms nonvolatile randomaccess memory nvramstores the system configuration, environmental monitoring logs, and the virtual configuration register. The memory controller is a digital circuit that manages the flow of data going to and from the computers main memory. Ddr sdram uses double data rate architecture to achieve highspeed data transfers. Design and implementation of ddr sdram controller using. The ddr sdram controller translates read and write requests from the local interface into all the necessary sdram command signals. Ds496 mch opb double data rate ddr synchronous dram. Sdram controller pdf ddr and ddr2 sdram controller compiler user guide. The ddr 4 controller is typically implemented in a system between the ddr and the bus master. Ddr and ddr2 sdram controller with altmemphy ip user guide.

Command execution engine the command execution engine is the main component of the ddr sdram controller. Double data rate, column address strobe cas, synchronous dynamic ram. Nowadays, memory devices are almost found in all systems, high speed and high performance memories are in great demand. 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. Us6940768b2 programmable data strobe offset with dll for. The memory controller interfaces dram and other subsystems. Double data rate ddr sdram controller lattice semiconductor nonpipelined version users guide signal descriptions the following tables show the interface signals for the ddr sdram controller. Dimm implementations have expanded from unregistered dimms to include registered dimms and fbdimms fully. A double data rate ddr synchronous dynamic ram sdram, or ddr sdram, memory controller employing a delay locked loop dll circuit to delay an sdram data strobe dqs signal to the center, or eye of the read data window. Customizable memory controller architecture and service.

Creating wider memory interfaces using multiple spartan6 fpga. Double data rate 2 synchronous dynamic randomaccess memory, officially abbreviated as ddr2 sdram, is a double data rate synchronous dynamic randomaccess memory interface. The ddr sdram controller uses a 90o phase shifted system clock to capture read data in the center of the data window. This paper is targeted for ddr sdram memory controller, which on one side has an interface for ahb and for ddr sdram on the other side. Pdf nowadays, ddr sdram double data rate synchronous dynamic random access memory has become the most popular class of memory used in computers due to its high speed, burst access and. This application note describes how to configure the mpmc to use different types of ddr. Double data rate synchronous dynamic randomaccess memory ddr sdram is a class of memory integrated circuits used in computers. The ddr3 sdram transmitted the read data and data strobes are edge aligned. Ddr sdram memory controller reference design xapp851 v1. We propose a memory controller which guarantees the refreshment of our ddr3 memory during the write operation. Most of the input signals to the state logic shown in figure 2 combine to form the discrete. Sama5d2 ddr controller capabilities the sama5d2 series mpu features a multiport ddr sdram controller mpddrc. Gddr sdram is distinct from commodity types of ddr sdram such as ddr3, although they share some core technologies. The data transition occurs at the both falling edges and rising.

Ddr and ddr2 sdram highperformance controller user guide. In this paper, the double data rate sdram controller is implemented using asic methodology. 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. For ddr4, lpddr4 and more advanced features, see the enhanced universal ddr memory controller umctl2 the upctl serves the memory control needs of applications with. Altera assumes no responsibility or liability arising out of the application or use of.

In highend applications, like microprocessors there will be specific built in peripherals to provide the interface to the sdram. The main controller layer consists of the ddr sdram controller state machine and fifo. 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. The purpose of these guidelines is to minimize boardrelated issues across multiple memory topologies while allowing maximum flexibility for. Ddr controller performance continues to be important, more new applications are demanding higher throughput, improved power management and better reliability. For the ddr sdram controller, the data passes through the controller, and the controller handles all ddr related synchronization and timing generation. Ddr3 sdram controller with altmemphy ip and altmemphy. Memory phy interface megafunction user guide altmemphy. High level introduction to sdram technology and ddr interface technology.

The mpmc multiport memory controller is used for interfacing ddr double data rate. Ds496 november 15, 2005 product specification allowable parameter combinations the mch opb ddr sdram controller supports up to 4 banks of memory. Ddr and ddr2 sdram high performance controllers ii. The memory controller is designed by using the corresponding signals given below in the diagram and every signal has an event associated with it. The phy layer consists of me mory initialization logic, and addresscommanddata io. Programmable burst lengths of 2, 4, and 8 programmable cas latency of 2, 2. In this paper, the implementation has been done in verilog hdl by using xilinx ise 9. Xilinx xapp851 ddr sdram controller using virtex5 fpga. This evolution has also been driven by how computer memories are used on dimms dual inline memory modules. Summary the memory controller block mcb is a dedicated embedded multiport memory controller that greatly simplifies the task of interfacing spartan6 devices to ddr3, ddr2, ddr, and lpddr memories. The mpddrc is a highbandwidth scrambleable 16bit or 32bit double data rate ddr multiport memory controller supporting up to 512mbyte 8bank ddr2, ddr3, ddr3l, lpddr1, lpddr2 and lpddr3 devices. A memory controller is provided and a method for transferring data between the memory controller and a memory device. The altmemphy megafunction is an interface between a memory controller and the. It superseded the original ddr sdram specification, and is superseded by ddr3 sdram launched in 2007.

Architecture of ddr sdram controller ddr sdram controller module receives addresses and control signals from the bus master. The memory controller can be implemented on an integrated circuit that also contains an execution unit. Ddr and ddr2 sdram controller with altmemphy ip user. Internal block diagram of the memory controller design.

Standard chip select generation for sram, rom and basic devices only requiring a chip select. The memory controller provides a generic command interface to the users application. This ddr controller is typically implemented in a system between the ddr and the processor. The basic steps that an asic design must go master, minimizes the effort to deal with the sdram.