Nasic implementation of ddr sdram memory controller pdf merger

In highend applications, like microprocessors there will be specific built in peripherals to provide the interface to the sdram. Implementation methodolody the ddr sdram controller architecture is implemented using verilog hdl. Implementation of ddr sdram controller using verilog hdl. 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 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.

Double data rate 2 synchronous dynamic randomaccess memory, officially abbreviated as ddr2 sdram, is a double data rate synchronous dynamic randomaccess memory interface. 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. 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. Ddr and ddr2 sdram high performance controllers ii. 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. A memory controller is provided and a method for transferring data between the memory controller and a memory device.

Double data rate, column address strobe cas, synchronous dynamic ram. Gddr sdram is distinct from commodity types of ddr sdram such as ddr3, although they share some core technologies. The main function of ddr3 memory controller sdram is used to program and to store a data. Dimm implementations have expanded from unregistered dimms to include registered dimms and fbdimms fully.

Rom and basic devices only requiring a chip select. In this paper, the implementation has been done in verilog hdl by using xilinx ise 9. To implement an mcb based memory interface, one of the two. Dram refresh mechanisms, penalties, and tradeoffs engineering. Asic implementation of ddr sdram memory controller amit bakshi school of electronics engineering.

Creating wider memory interfaces using multiple spartan6 fpga. Pdf nowadays, ddr sdram double data rate synchronous dynamic random access memory has become the most popular class of memory used in. Second generation of ddr memory ddr2 scales to higher clock. R ddr sdram interface design ddr sdram controller interface figure 4 presents the state machine of the ddr sdram command generation state machine. The ddr sdram controller architecture is shown in figure 2. The ddr 4 controller is typically implemented in a system between the ddr and the bus master.

Command execution engine the command execution engine is the main component of the ddr sdram controller. The ddr3 sdram transmitted the read data and data strobes are edge aligned. Ddrsdram layout considerations for mcf547x8x processors. 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. Xilinx ug388 spartan6 fpga memory controller user guide. Sama5d2 ddr controller capabilities the sama5d2 series mpu features a multiport ddr sdram controller mpddrc. Implementation of fpga based memory controller for ddr2.

In addition, this volume includes basic information for various memory. 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. Memory phy interface megafunction user guide altmemphy. 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. Double data rate synchronous dynamic randomaccess memory ddr sdram is a class of memory integrated circuits used in computers. These steps are followed before the controller issues the commands to the memory. Synchronous dram sdram has become a mainstream memory of choice in design due to its speed. Hardware and layout design considerations for ddr3 sdram. We propose to merge the write and the refresh operations to. 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 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. Memory design considerations when migrating to ddr3. The memory controller interfaces dram and other subsystems. Implementation of ddr sdram memory controller for embedded soc. Ahb interfaced high speed ddr sdram memory controller. Ddr2mddr memory controller 1 introduction this document describes the ddr2mobile ddr memory controller. For the ddr sdram controller, the data passes through the controller, and the controller handles all ddr related synchronization and timing generation. Ddr sdram timing parameters and can be changed by the user to suit the ddr sdram memory timings being used thus giving the. This memory device provides higher reliability, availability and serviceability than other ddr memories. Data rate sdram controller and integrated it with a pro cessor. The double data rate ddr synchronous dynamic random access memory sdram controller is a generalpurpose memory controller that interfaces with industry standard ddr sdram. Ddr sdram transfers data on both the rising and falling edge of the clock.

For ddr4, lpddr4 and more advanced features, see the enhanced universal ddr memory controller umctl2. The ddr memory controller design for the ddr sdram and the connection between the fpga provides a solution 3. 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. Altera assumes no responsibility or liability arising out of the application or use of. 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. The data bus transfers data on both rising and falling edge of the clock ddr sdram. Links to ddrddr2 sdram application notes, reference designs, development boards.

Ddr sdram interface bus signals burst type burst type. 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. This interface reduces the effort to integrate the module with the remainder of the. The purpose of these guidelines is to minimize boardrelated issues across multiple memory topologies while allowing maximum flexibility for. The ddr and ddr2 sdram controllers with altmemphy ip work in conjunction with the altera altmemphy megafunction. The cortexm3 processor has a predefined memory map for code space, data space, and system space.

This paper analyzes the current international technology trends and storage controller ddr2 sdram controller detailed technical specifications. 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. Design and implementation of high speed pipelined ddr sdram. The memory controller is designed by using the corresponding signals given below in the diagram and every signal has an event associated with it. Us6940768b2 programmable data strobe offset with dll for. Ddr3 memory controller users guide literature number. 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. Ddr3 sdram controller with altmemphy ip and altmemphy. The function of each emc pin for static memory, sdr sdram and ddr sdram is shown in. Ddr 3 sdram memory controller ip core hitech global.

Standard chip select generation for sram, rom and basic devices only requiring a chip select. Presentation provides both a starter introduction to what dram is and how it operat. Double data rate originally referred to as simple ddr and it was designed to replace sdram. Sdram controller pdf ddr and ddr2 sdram controller compiler user guide. Ddr sdram uses double data rate architecture to achieve highspeed data transfers. Implementation figure 1 represents the basic block diagram of ddr2 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. We propose a memory controller which guarantees the refreshment of our ddr3 memory during the write operation.

This evolution has also been driven by how computer memories are used on dimms dual inline memory modules. Ddr memory controller design based on fpga scientific. The controller generates command signals and based on these signals the data is either read or written to a particular memory location. Most of the input signals to the state logic shown in figure 2 combine to form the discrete. In this paper, the overall architecture of the ddr4 sdram controller is proposed. 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. 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. 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. 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 memory controller block mcb is a dedicated embedded multiport memory controller.

The memory controller can be implemented on an integrated circuit that also contains an execution unit. 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. Designware basic universal ddr memory and protocol. Ddr controller provides a synchronous command interface to the ddr sdram memory along with several control signals. 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. Programmable burst lengths of 2, 4, and 8 programmable cas latency of 2, 2. The altmemphy megafunction is an interface between a memory controller and the memory devices, and performs read and write operations to the memory. A memory controller consists of a refresh circuit and a digital circuitry that controls the data flow to and from the memory. Ds496 november 15, 2005 product specification allowable parameter combinations the mch opb ddr sdram controller supports up to 4 banks of memory. Xilinx xapp851 ddr sdram controller using virtex5 fpga. 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. Mch opb double data rate ddr synchronous dram sdram controller 6. The xilinx mch opb ddr2 sdram controller is a soft ip. Implementation of physical design in ddr sdram memory.

To further organize the data transfer memory controllers are designed. Ddr sdram controller pipelined lattice semiconductor. Introduction to ddr sdram memory controller the ddr sdram uses double data rate architecture to achieve highspeed data transfers. The work concentrates on the relative study of two memory controllers viz. Xilinx xapp496 creating wider memory interfaces using. Nowadays, memory devices are almost found in all systems, high speed and high performance memories are in great demand.

For better throughput and speed, the controllers are to be designed with clock. Because the ddr sdram has twice the sdram memory data rate, now has been widely used. The ddr sdram controller translates read and write requests from the local interface into all the necessary sdram command signals. 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. The command logic block generates a readwrite command. 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. 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. Customizable memory controller architecture and service. The controllers translate readandwrite requests from the local interface into all the necessary sdram command signals. The phy layer consists of me mory initialization logic, and addresscommanddata io.

Sdram controllers with altmemphy ip offer the highperformance controller ii. Sdram synchronous dram, ddr double data rate sdram, ddr2 double data rate 2 sdram, and ddr3 double data rate 3 sdram. The result is a potential doubling of the bandwidth between the mpu and the ddr sdram. Tms320c674xomapl1xprocessor ddr2mddr memory controller. The lovehate relationship with ddr sdram controllers.

Architecture of ddr sdram controller ddr sdram controller module receives addresses and control signals from the bus master. Pdf refreshaware ddr3 barrel memory controller with. Ddr sdram architecture, which became highly success ful and was. Implementation of fpga based memory controller for ddr2 sdram. This application note describes how to configure the mpmc to use different types of ddr. The project also contains a simple push button interface for testing on the dev board. The access latency or access speed solely depends on the implementation of memory controller.

The mpmc multiport memory controller is used for interfacing ddr double data rate. Sdram generations offers high performance and bandwidth. Ddr sdram memory controller reference design xapp851 v1. As we use a single port memory controller, we need a channel merger block to merge both. Asic implementation of ddr sdram memory controller. 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. This is a very a simple sdram controller which works on the de0 nano. Ddr and ddr2 sdram highperformance controller user guide. Ds496 mch opb double data rate ddr synchronous dram. 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. Design and simulation of ddr3 sdram controller for high.

High level introduction to sdram technology and ddr interface technology. As shown in the architecture block diagram of figure 21, page 16, the mcb has two basic. 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. The memory controller provides a generic command interface to the users application. Chapter 5 implementation of the customizable architecture of. The core also has separate datain and dataout buses at the user interface. The designed ddr controller supports data width of 64 bits, burst length of 4 and cas column address strobe latency of 2. 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. In this paper, the double data rate sdram controller is implemented using asic methodology. 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. Ddr sdram referred to as ddr transfers data on both the rising and falling edge of the clock.

It superseded the original ddr sdram specification, and is superseded by ddr3 sdram launched in 2007. The chip density of ddr sdram is 1 gb and that of ddr2 sdram is 4 gb. Internal block diagram of the memory controller design. The basic steps that an asic design must go master, minimizes the effort to deal with the 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. Improved description for implementing altera memory interface ip chapter. 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 ddr sdram interface signals are the same for all core con. The main controller layer consists of the ddr sdram controller state machine and fifo. The altmemphy megafunction is an interface between a memory controller and the. The basic functional block diagram of ddr sdram controller shown in fig. Cortexm3 processor, up to 512 kb of envm, 64 kb of esram, and memory interfaces for ddrsdr sdram for program code, and data.

The data transition occurs at the both falling edges and rising. Thus ddr2 sdram has higher speed, density and low power consumption then ddr sdram. Ddr and ddr2 sdram controller with altmemphy ip user. The controller mainly aims the interaction of memory and processor with a goal of well refined memory designs. Deepali sharma et al, ijcsit international journal of.

The ddr sdram controller supports data width of 64 bits and. Design and implementation of high performance ddr3. Ddr controller performance continues to be important, more new applications are demanding higher throughput, improved power management and better reliability. An sdram controller specifically for providing the correct memory control signals, connections, and timing for sdram devices. Ddr and ddr2 sdram controller with altmemphy ip user guide. The core accepts commands using a simple local interface and translates them to the command sequences required by ddr3 sdram devices. Each bank of memory has its own independent base address and address range. 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. Ddr and ddr2 sdram controllers with altmemphy ip user guide 1. Design and implementation of ddr sdram controller using. Synchronous dram sdram is preferred in embedded system memory design because of its speed and pipelining capability. Pdf the design and simulation of a 400533mbps ddrii sdram.