Altera External Memory PHY Interface User Manual

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External Memory PHY Interface (ALTMEMPHY)

(nonAFI) Megafunction User Guide

101 Innovation Drive San Jose, CA 95134 www.altera.com

UG-01014-7.3

Software Version: 9.1 SP1 Document Version: 7.3 Document Date: January 2010

Copyright © 2010 Altera Corporation. All rights reserved. Altera, The Programmable Solutions Company, the sty lized Altera logo, specific device designations, and all other words and logos that are identified as trademarks and/or service marks are, unless noted otherwise, the trademarks and service marks of Altera Corporation in the U.S. and other countries. All other product or service names are the property of their respective holders. Altera products are protected under numerous U.S. and foreign patents and pending applications, maskwork rights, and copyrights. Altera warrants performance of its semiconductor products to current specifications in accordance with Altera's standard warranty, but reserves the right to make changes to any products and services at any time without notice. Altera assumes no responsibility or liability arising out of the application or use of any information, product, or service described herein except as expressly agreed to in writing by Altera Corporation. Altera customers are advised to obtain the latest version of device specifications before relying on any published information and before placing orders for products or services

Chapter 1. About this Megafunction

Chapter 2. Parameter Settings

Memory Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–2

Use the Preset Editor to Create a Custom Memory Preset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2–4

Creating an Emulated x36 QDR II+/QDR II SRAM ALTMEMPHY Variation . . . . . . . . . . . . . . . . . 2–7

Chapter 3. Functional Description—ALTMEMPHY (nonAFI)

QDR II+/QDR II SRAM Calibration Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–1

PHY-to-Controller Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–4

Initialization Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–5

DDR SDRAM Initialization Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–5

DDR2 SDRAM Initialization Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–7

ALTMEMPHY Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–9

DDR2 and DDR SDRAM Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–9

QDR II+/QDR II SRAM Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–20

Understanding the Testbench . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–25

PLL Initialization and Lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–25

Memory Device Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–25

Interface Training and Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–25

Write Training Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–26

Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–26

Functional Memory Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–26

Functional Simulation—the ModelSim Wave and Transcript Window . . . . . . . . . . . . . . . . . . . . . . . . . 3–27

Full Window Stage Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–27

Initialization Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–29

Write Training Data Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–31

Read Calibration Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–33

Functional Memory Use Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–37

Additional Debug Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–39

PLL and PLL Reconfiguration Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–39

Calibration Status Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–40

Additional Calibration Status Interface Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–40

Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–41

Clocks and Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–41

Calibration Process Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–41

Local Interface Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–42

DDR2/DDR SDRAM Half-Rate Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–42

Handshake Mechanism Between Read Commands and Read Data . . . . . . . . . . . . . . . . . . . . . . . 3–43

Handshake Mechanism Between Write Commands and Write Data . . . . . . . . . . . . . . . . . . . . . . 3–44

DDR2/DDR SDRAM Full-Rate Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–47

Handshake Mechanism Between Read Commands and Read Data . . . . . . . . . . . . . . . . . . . . . . . 3–47

Handshake Mechanism Between Write Commands and Write Data . . . . . . . . . . . . . . . . . . . . . . 3–49

Chapter 4. Support for Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices

DDR2/DDR SDRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–1

Half-Rate Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–1

Read Datapath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–1

Clock and Reset Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–3

Write Datapath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–8

Address and Command Datapath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–9

Full-Rate Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–11

Read Datapath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–11

Clock and Reset Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–11

Write Datapath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–11

Address and Command Datapath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4–11

Chapter Info. Additional Information

Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Info–1

How to Contact Altera . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Info–2

Typographic Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Info–2

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

1. About this Megafunction

This user guide is only for legacy designs as it describes the specifications and functional descriptions of the ALTMEMPHY megafunctions that are common to non-Altera PHY interface (nonAFI) variations. This user guide also describes the implementation of the QDR II+ and QDR II SRAM interfaces for legacy designs targeted for Arria

The ALTMEMPHY megafunction is an interface between a memory controller and memory devices and performs read and write operations to the memory. The megafunction is available as a stand-alone product or as an integrated product with

Altera

high-performance memory controllers. As a stand-alone product, use the

ALTMEMPHY megafunction with either custom or third-party controllers.

The ALTMEMPHY megafunction for DDR3, DDR2, and DDR SDRAM offers two different PHY-to-controller interfaces: Altera PHY interface (AFI) and nonAFI. The AFI is supported for all variations of ALTMEMPHY for DDR3, DDR2, and DDR SDRAM. ALTMEMPHY for DDR3 SDRAM only support the AFI. The AFI results in a simpler connection between the PHY and controller, so Altera recommends that you use the AFI for new designs; only use the nonAFI for legacy designs.

GX, Stratix®II, and Stratix II GX devices.

f For information about using the external memory interfaces (DDR3, DDR2, and DDR

SDRAM) with AFI and the ALTMEMPHY megafunction, refer to Volume 3:

Implementing Altera Memory Interface IP of the External Memory Interface Handbook.

f For more information about the ALTMEMPHY megafunction features, refer to Volume

3: Implementing Altera Memory Interface IP of the External Memory Interface Handbook.

f For information about issues on the ALTMEMPHY megafunction in a particular

Quartus

II software version, refer to the Quartus II Software Release Notes

1–2 Chapter 1: About this Megafunction

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © Juanuary 2010 Altera Corporation

2. Parameter Settings

This section describes the memory preset settings for the ALTMEMPHY (nonAFI) megafunction with the QDR II+/QDR II SRAM interfaces only.

f For information about using the MegaWizard

™

Plug-In Manager or the SOPC Builder

flow to implement the ALTMEMPHY megafunction, refer to the Getting Started chapter in Volume 3: Implementing Altera Memory Interface IP of the External Memory

Interface Handbook.

The ALTMEMPHY Parameter Settings page in the ALTMEMPHY MegaWizard interface (Figure 2–1) allows you to parameterize the following settings:

■ Memory Settings

■ PHY Settings

■ Controller Interface Settings

1 The options for PHY Settings tab are editable if they apply to the Altera device that

you have chosen for your interface. Otherwise, the options are disabled. The options for Controller Interface Settings tab are disabled when you are creating an ALTMEMPHY (nonAFI) megafunction for QDR II+/QDR II SRAM interface.

f For more information about the PHY Settings and the Controller Interface Settings,

refer to the Parameter Settings chapter in Volume 3: Implementing Altera Memory Interface

IP of the External Memory Interface Handbook

2–2 Chapter 2: Parameter Settings

Figure 2–1. ALTMEMPHY Parameter Settings Page

The text window at the bottom of the MegaWizard Plug-In Manager displays information about the memory interface, warnings (for example, if you are creating an interface above the maximum frequency supported), and errors if you are trying to create something that is not supported. The Finish button is disabled until you fix all the errors indicated in this window.

The following section describes the Memory Settings tab for QDR II+/QDR II SRAM interface in more detail.

Memory Settings

In the Memory Settings tab, you can choose the frequency of operation for the device and a particular memory device for your system. Under General Settings, you can choose the device family, speed grade, and clock information. In the middle of the page (left-side), you can filter the available memory device listed on the right side of the Memory Presets dialog box, refer to Figure 2–1. If you cannot find the exact device that you are using, choose a device that has the closest specifications, then manually modify the parameters to match your actual device by clicking Modify parameters, next to the Selected memory preset field.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 2: Parameter Settings 2–3

Tab le 2– 1 describes the General Settings available on the Memory Settings page of

the ALTMEMPHY MegaWizard interface.

Table 2–1. General Settings

Parameter Name Description

Device family Targets device family. The device family selected here must match the device family selected on

MegaWizard page 2a.

Speed grade Selects a particular speed grade of the device (for example, 2, 3, or 4 for the Stratix III device

family).

PLL reference clock frequency

Determines the clock frequency of the external input clock to the PLL. Ensure that you use three decimal points if the frequency is not a round number (for example, 166.667 MHz or 100 MHz) to avoid a functional simulation or a PLL locking issue.

Memory clock frequency

Determines the memory interface clock frequency. If you are operating a memory device below its maximum achievable frequency, ensure that you enter the actual frequency of operation rather than the maximum frequency achievable by the memory device. Also, ensure that you use three decimal points if the frequency is not a round number (for example, 333.333 MHz or 400 MHz) to avoid a functional simulation or a PLL locking issue.

Controller data rate Selects the data rate for the memory controller. Sets the frequency of the controller to equal to

either the memory interface frequency (full-rate) or half of the memory interface frequency (half-rate).

Local interface clock frequency

This field’s value depends on the memory clock frequency and controller data rate, and whether or not you turn on the Enable Half Rate Bridge option.

Local interface width This field’s value depends on the memory clock frequency and controller data rate, and whether or

not you turn on the Enable Half Rate Bridge option.

Tab le 2– 2 describes the options available to filter the Memory Presets that are

displayed. This section is where you indicate that you are creating a datapath for QDR II+/QDR II SRAM.

Table 2–2. Memory Presets List

Parameter Name Description

Memory type You can filter the type of memory to display. For the ALTMEMPHY megafunction with nonAFI, select

QDR II+ SRAM and QDR II SRAM.

Memory vendor You can filter the memory types by vendor. JEDEC is also one of the options, allowing you to

choose the JEDEC specifications. If your chosen vendor is not listed, you can choose Other for QDR II+/QDR II SRAM interfaces. Then, pick a device that has similar specifications to your chosen device and check the values of each parameter. Make sure you change the each parameter value to match your device specifications.

Memory format You can filter the type of memory by format (for example, components or DIMM packages). This

option is only available for DDR3, DDR2, and DDR SDRAM interfaces.

Maximum frequency You can filter the type of memory by the maximum operating frequency.

2–4 Chapter 2: Parameter Settings

Use the Preset Editor to Create a Custom Memory Preset

Pick a device in the Memory Presets list that is closest or the same as the actual memory device that you are using. Then, click the Modify Parameters button to parameterize the following settings in the Preset Editor dialog box:

■ Memory attributes—These are the settings that determine your system's number of

DQ, DQS, address, and memory clock pins.

■ Memory initialization options—These settings are stored in the memory mode

registers as part of the initialization process.

■ Memory timing parameters—These are the parameters that create and

time-constraint the PHY.

1 Even though the device you are using is listed in Memory Presets, ensure that the

settings in the Preset Editor dialog box are accurate as some parameters may have been updated in the memory device datasheets.

You can change the parameters with a white background to reflect your system. You can also change the parameters with a gray background so the device parameters match the device you are using. These parameters in gray background are characteristics of the chosen memory device and changing them creates a new custom memory preset. If you click Save As (at the bottom left of the page) and save the new settings in the <quartus_install_dir>\quartus\common\ip\altera\altmemphy\lib\ directory, you can use this new memory preset in other Quartus II projects created in the same version of the software.

When you click Save, the new memory preset appears at the bottom of the Memory Presets list in the Memory Settings tab.

1 If you save the new settings in a directory other than the default directory, click Load

Preset in the Memory Settings tab to load the settings into the Memory Presets list.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 2: Parameter Settings 2–5

QDR II+/QDR II SRAM Preset Editor Page

Figure 2–2 shows the Preset Editor page for the ALTMEMPHY variation for

QDR II+/QDR II SRAM interfaces.

Figure 2–2. Preset Editor for QDR II+/QDR II SRAM Interfaces

Tab le 2– 3 through Ta bl e 2 –5 describe the QDR II+/QDR II SRAM parameters

available for memory attributes, initialization options, and timing parameters. The QDR II+ SRAM devices have the same parameters as QDR II SRAM devices, but their value ranges can differ. Confirm that the value you have chosen is valid in the ALTMEMPHY MegaWizard interface.

2–6 Chapter 2: Parameter Settings

Table 2–3. QDR II+/QDR II SRAM Attribute Settings

Parameter Name Range (1) Units Description

De-rate ×18 timing for emulation ×36 mode

Enabled or Disabled — Allows the ALTMEMPHY megafunction to derate the timing

calculation when creating ×36 QDR II+/QDR II SRAM interfaces by using two ×18 DQS/DQ groups. For more information on ×36 emulation, refer to “Creating an Emulated

x36 QDR II+/QDR II SRAM ALTMEMPHY Variation” on page 2–7.

Output clock pairs from FPGA

1–16 pairs Selects the number of differential clock pairs driven from the

FPGA to the memory. More clock pairs reduce the loading of each output when interfacing with multiple memory devices. Memory clock pins use the signal splitter feature in Stratix III and Stratix IV devices for differential signaling.

Memory depth expansion

Memory interface D/Q data bits

1–2 chips Picks the number of chip selects of memory supported. This

option is for memory depth expansion.

8–288 bits Defines the width of external memory read and write data bus.

Multiply the number of devices with the number of DQ pins per device when you create width-expanded memory interfaces. Even though the GUI allows you to choose 288-bit DQ width, the interface data width is limited by the number of pins on the device. For best performance, have the whole interface on one side of the device.

Memory vendor Others — Displays the name of the memory vendor for all supported

memory standards.The ALTMEMPHY megafunction only has generic QDR II+/QDR II SRAM data sheet information listed under vendor as Other.

Maximum memory frequency

Drive BWS_N/NWS_N

See the memory device

MHz Defines the maximum frequency supported by the memory.

data sheet

Yes or No — Enables the use of the write select pins for write operations

when set to Yes.

from FPGA

DQ bits per chip 8, 9, 18, 36 bits Defines the width of D and Q data bus on each QDRII SRAM

chip.

Address width 15–25 bits Sets the number of address bits.

I/O standard QDR II+ SRAM: 1.5 V

HSTL Class I;

— Selects the I/O standard to be applied to the memory interface

pins.

QDR II SRAM: 1.8 V HSTL

Class I or 1.5 V HSTL

Class I

Note to Table 2–3:

(1) The range values depend on the actual memory device used.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 2: Parameter Settings 2–7

Table 2–4. QDR II+/QDR II SRAM Initialization Options

Parameter Name Range Units Description

Memory burst length

4 beats Sets the memory burst length for the interface. As the

QDR II+/QDR II SRAM ALTMEMPHY megafunction only supports half-rate designs, only a memory burst length of four is supported, which equates to a local burst length of one.

Memory latency setting

1.5 (QDR II

SRAM) or 2.5

(QDR II+ SRAM)

Cycles Sets the memory latency. Altera devices only support latency of

2.5 for QDR II+ SRAM and 1.5 for QDR II SRAM. QDR II+ SRAM with latency of 2.0 is not supported with Altera devices, even though the ALTMEMPHY MegaWizard interface shows this as an option.

Table 2–5. QDR II+/QDR II SRAM Timing Parameter Settings

Parameter Name Range Units Description

CQHQV

CQHQX

(1) 0–2,000 ps Echo clock high to inverted echo clock high.

CQHCQnH

(1) 0–2,000 ps Echo clock high.

CQH

Note to Table 2–5:

(1) This parameter is available for QDR II+ SRAM interfaces only.

200–500 ps Address setup time to K clock rise.

200–500 ps Control setup time to K clock rise.

200–500 ps Address hold time to K clock rise.

200–500 ps Control hold time after K clock rise.

200–500 ps D setup time to K clock rise.

200–500 ps D hold time to K clock rise.

200–500 ps Echo clock high to data valid.

200–500 ps Echo clock high to data invalid.

Creating an Emulated x36 QDR II+/QDR II SRAM ALTMEMPHY Variation

From software implementation point of view, creating a ×36 emulated QDR II+/QDR II SRAM interface is exactly the same as implementing an interface with two ×18 QDR II+/QDR II SRAM devices. In the Memory Settings page of the ALTMEMPHY MegaWizard interface, select a ×18 QDR II+/QDR II SRAM with the same timing specifications as ×36 QDR II+/QDR II SRAM device (see Figure 2–3).

For more information about ×36 emulation for QDR II+/QDR II SRAM interfaces, refer to the Exceptions for ×36 Emulated QDR II and QDR II+ SRAM Interfaces in Arria II

GX, Stratix III and Stratix IV Devices section in Volume 2: Device, Pin, and Board Layout

Guidelines of the External Memory Interface Handbook.

2–8 Chapter 2: Parameter Settings

Emulated Device

Actual Device

Figure 2–3. Select a ×18 Device

To indicate that you are interfacing with 36-bit read and 36-bit write data follow these steps:

1. On the Memory Settings page click Modify Parameters, to open the Preset Editor, see Figure 2–4.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 2: Parameter Settings 2–9

Figure 2–4. Preset Editor

2. For Derate ×18 timing for ×36 emulation mode, select Enabled. This setting tells the report_timing.tcl script to use the derating factor for ×36 emulation. If you have modified the board such that the slew rate of the ×36 emulated (doubleloaded) CQ/CQn signal is comparable to a non-emulated (single-loaded) CQ/CQn signal, you can leave this option as Disabled, as there is no slew rate degradation in your design.

3. For Output clock pairs from FPGA select 1. Only one mem_clk and mem_clk_n pair connect to the QDR II+/QDR II SRAM device's K and Kn ports..

4. Memory interface D/Q data bits select 36, which is the data bus width for ×36 QDR II+/QDR II SRAM interfaces.

After generation, for devices with F780 and F1152 packages that do not have ×18 DQ groups necessary to fit the write data bus, follow these steps to modify the <variation_name>_pin_assignments.tcl file to change the assignments to use ×9 DQ groups:

1. Remove the memory interface data pin group assignment of 18 for write data bus and DM pins in the Assignment Editor.

2. Find the following assignments in the <variation_name>_pin_assignments.tcl.

set_instance_assignment -name MEMORY_INTERFACE_DATA_PIN_GROUP 18 -to ${d_pin_name}\[0..17\] -from ${d_pin_name}\[0\]

2–10 Chapter 2: Parameter Settings

set_instance_assignment -name MEMORY_INTERFACE_DATA_PIN_GROUP 18 -to ${dm_pin_name}\[0..1\] -from ${d_pin_name}\[0\]

set_instance_assignment -name MEMORY_INTERFACE_DATA_PIN_GROUP 18 -to ${d_pin_name}\[18..35\] -from ${d_pin_name}\[18\]

set_instance_assignment -name MEMORY_INTERFACE_DATA_PIN_GROUP 18 -to ${dm_pin_name}\[2..3\] -from ${d_pin_name}\[18\]

3. Replace with the following assignment:

set_instance_assignment -name MEMORY_INTERFACE_DATA_PIN_GROUP 9 -from ${d_pin_name}[0] -to ${d_pin_name}[0..8]

set_instance_assignment -name MEMORY_INTERFACE_DATA_PIN_GROUP 9 -from ${d_pin_name}[0] -to ${dm_pin_name}[0]

set_instance_assignment -name MEMORY_INTERFACE_DATA_PIN_GROUP 9 -from ${d_pin_name}[18] -to ${d_pin_name}[18..26]

set_instance_assignment -name MEMORY_INTERFACE_DATA_PIN_GROUP 9 -from ${d_pin_name}[18] -to ${dm_pin_name}[2]

set_instance_assignment -name MEMORY_INTERFACE_DATA_PIN_GROUP 9 -from ${d_pin_name}[9] -to ${d_pin_name}[9..17]

set_instance_assignment -name MEMORY_INTERFACE_DATA_PIN_GROUP 9 -from ${d_pin_name}[9] -to ${dm_pin_name}[1]

set_instance_assignment -name MEMORY_INTERFACE_DATA_PIN_GROUP 9 -from ${d_pin_name}[27] -to ${d_pin_name}[27..35]

set_instance_assignment -name MEMORY_INTERFACE_DATA_PIN_GROUP 9 -from ${d_pin_name}[27] -to ${dm_pin_name}[3]

4. Save the <variation_name>_pin_assignments.tcl file.

The rest of the RTL implementation is similar to a regular QDR II+/QDR II SRAM interface.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

3. Functional Description—ALTMEMPHY

CQn

Input from

Sequencer

Shift Register

1/2

shifted

Half-Rate Data

CQn

shifted

This chapter describes the QDR II+/QDR II SRAM calibration process, the typical PHY-to-Controller interfaces that are connected to the ALTMEMPHY variation and the signal name prefixes each module uses for nonAFI variations.

1 Altera recommends that you use the AFI for new designs; only use the nonAFI for

existing designs.

QDR II+/QDR II SRAM Calibration Process

1 This section describes the calibration process for QDR II+/QDR II SRAM interfaces

only. For information about the calibration process for DDR2 and DDR SDRAM, refer to the Calibration section in the DDR and DDR2 SDRAM High-Performance Controllers

and ALTMEMPHY IP User Guide.

The calibration process of a QDR II+/QDR II SRAM device is considerably simpler than that of a calibration process for a DDR2/DDR SDRAM device. The calibration process involves selecting the right phase of the resynchronization clock to capture the read data at half rate. Figure 3–1 shows the generation of the resynchronization clock which then clocks the HDR registers in the IOE. During calibration, the sequencer determines whether to use the half-rate clock or the inverted half-rate clock to capture the half-rate data.

(nonAFI)

Figure 3–1. Resynchronization Clock in QDR II+/QDR II SRAM ALTMEMPHY Megafunction

3–2 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

Calibration start

Write 0's pattern to address 3

Write 1's pattern to address 5

Setup resync_clk_1x phase associated with

DQS group being calibrated

Read 0's pattern

Read 1's pattern

Start latency counter and search for

0's followed by 1's pattern

All DQS groups

calibrated?

Align all DQS groups to worst case latency

Calibration successful

Ye s

Timed out for both

phases of

resync_clk_1x

Invert resync_clk_1x phase

Latency counter

timeout

Calibration

unsuccessful

Ye s

If pattern found

QDR II+/QDR II SRAM Calibration Process

The clock CQ coming from the QDR II+/QDR II SRAM is delayed and is divided by two to generate a half-rate clock (resync_clk_1x). Data is captured on the rising edges of the shifted CQ and shifted CQn signals. There is one resync_clk_1x per DQS group. QDR II+/QDR II SRAM devices can only have one DQS group per device, which means that there is one resync_clk_1x signal associated with each memory device. This signal clocks the registers doing the full-rate to half-rate conversion. It also clocks the front side of the read datapath clock-crossing FIFO. There is one FIFO per DQS group (or memory device).

The resync_clk_1x signal can be inverted or not inverted. You can transfer data in the correct byte order with one of these options. The main objective of calibration is to find out whether the resync_clk_1x signal requires inversion, which is done by loading the shift register, see Figure 3–1 (at most twice per QDR II+/QDR II SRAM device). Each memory device is calibrated one after the other.

Figure 3–2 shows the QDR II+/QDR II SRAM calibration flowchart.

Figure 3–2. QDR II+/QDR II SRAM Calibration Flowchart

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–3

QDR II+/QDR II SRAM Calibration Process

During the QDR II+/QDR II SRAM calibration, the sequencer first writes all 0s to address space 3 in the external memory, followed by all 1s to address space 5. It then loads the scan chain for the first time, to program the first setting for resync_clk_1x.

The sequencer then starts reading 0s from address space 3 several times, followed by a single read from address space 5 and starts the latency counter. If a pattern of all 0s followed by all 1s is read before the latency counter reaches its time-out value (31 clock cycles), the latency value for that memory device is stored.

If all 0s followed by all 1s is not found when reading back from memory and the latency count has reached the time-out value, the sequencer loads the scan chains a second time to invert the resync_clk_1x signal. The sequencer then starts reading from address space 3 several times, followed by a single read from address space 5 as before and starts the latency counter again. If all 0s followed by all 1s are read back from memory, the latency value for that memory device is stored.

1 The training pattern must be read back correctly on this second iteration (if it was not

already read correctly on the first iteration). If it is not read back correctly, it indicates an underlying problem in the system.

The previous process is repeated until all memory devices are tested and a latency value obtained for each device.

The latency values found for the different devices are compared with each other. If necessary, they are aligned to the worst case latency (or to the user-requested deterministic latency value if this option is used), which done by adjusting address pointers in order to add latency to some of the read datapath RAMs inside the ALTMEMPHY megafunction until the latency associated with all of the memory devices is aligned to the worst case latency measured.

1 You cannot have a latency difference of more than two PHY clock cycles between all

the QDR II+/QDR II SRAM devices in non-deterministic latency mode.

When calibration has finished, the sequencer hands over control to the driver/user logic, and generates the p_rdata_out_valid flag to indicate when read data is valid. The sequencer also outputs the following signals upon completion of calibration:

■ p_ready—Indicates completion of the calibration process (but does not mean

calibration was successful). This signal is renamed as the ctl_usr_mode_rdy signal at the ALTMEMPHY top-level file.

■ p_calibration_successful—Indicates calibration was successfully

completed. This port is renamed resynchronisation_successful port at the ALTMEMPHY top-level file.

■ p_user_defined_latency_ok—Indicates that the read latency requested by

the user was achievable, when using deterministic latency. This port is not instantiated at the top-level of the file. Currently this signal exists at the sequencer_wrapper file level only.

■ p_detectedlatency—Specifies the read latency achieved in phy_clk clock

cycles. This port is renamed ctl_rlat port at the ALTMEMPHY top-level file.

3–4 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

User logic (or example driver)

Auto-calibration

Memory Controller

Clock & reset management

ALTMEMPHY

Addr & Cmd Path

Write path

Read path

Ports named local_*

Ports named ctl_*

Ports named ctl_mem_*

Ports named mem_*

External Memory

PHY-to-Controller Interfaces

VT tracking is not required because the read strobe from the QDR II+/QDR II SRAM memory is continuous. So all registers in the I/O to the read RAM path are clocked using a clock that is derived from the QDR II+/QDR II SRAM read clock.

1 For more information about the QDR II+/QDR II SRAM signals, refer to “QDR

II+/QDR II SRAM Signals” on page 3–20.

PHY-to-Controller Interfaces

The nonAFI’s autocalibration logic relies on the services of the memory controller to perform its calibration writes, reads, and memory initialization, so it must have control of the controller's local interface during the initial calibration stage. The ALTMEMPHY megafunction has four interfaces that all must be connected appropriately. Figure 3–3 shows the four interfaces.

1 As an SRAM, the PHY for QDR II+/QDR II SRAM lacks most of the ctl_ and

local_ ports as you can use a driver that acts as a controller to generate read and

write commands and data in the QDR II+/QDR II SRAM PHY.

Figure 3–3. The Four ALTMEMPHY Megafunction Interfaces

The four ALTMEMPHY interfaces, from left to right, are:

1. The local interface is the interface between the user logic and the memory controller. The signals between user logic and the controller traverse through the ALTMEMPHY megafunction. This can either be an Avalon slave interface or a Native interface. All the ports on this interface have their names prefixed with local_; for example, local_init_done. During the initial calibration period, the auto-calibration logic takes control of this interface and issues the write and read requests that the memory controller requires. When the calibration process is complete, control is handed back to the user logic and normal operation occurs. The ALTMEMPHY megafunction auto-calibration logic does not require any further access to the memory controller when the initial autocalibration is complete.

Memory-Mapped

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–5

Initialization Timing

2. The ALTMEMPHY-controller local interface is the interface between the ALTMEMPHY megafunction and the controller local interface. All the port names on this interface are prefixed with ctl_; for example, ctl_init_done. This interface connects the ALTMEMPHY megafunction to the controller’s local interface and is of the same type as the local interface, either an Avalon-MM interface or a native interface. When the calibration process is complete, this connection becomes a straight-through connection and you have complete control of the memory controller.

3. The ALTMEMPHY-controller command interface is the interface between the controller and ALTMEMPHY. All the ports on this interface are prefixed with ctl_mem_; for example, ctl_mem_rdata. They are clocked by the phy_clk. This interface contains the memory control and address signals from the controller to the memory. The controller also sends write data to, and receives read data from, the external memory through this interface. All the signals on this interface are clocked at the phy_clk rate. The ALTMEMPHY megafunction converts between this clock and the memory interface clock.

4. The fourth interface is between the ALTMEMPHY megafunction and the external memory devices and consists of the memory address, command, and data pins. These must be connected directly to the external pins of your Altera FPGA.

Initialization Timing

DDR SDRAM initialization timing is different to DDR2 SDRAM initialization timing.

DDR SDRAM Initialization Timing

f For DDR2 SDRAM initialization timing, see “DDR2 SDRAM Initialization Timing” on

page 3–7.

The DDR SDRAM high-performance controller initializes the SDRAM devices by issuing the following memory command sequence:

■ NOP (for 200 µs, programmable)

■ PCH

■ Extended LMR (ELMR)

■ LMR

■ NOP (for 200 clock cycles, fixed)

■ PCH

■ ARF

■ LMR

Figure 3–4 on page 3–6 shows a typical initialization timing sequence. The length of

time between the reset and the first PCH command should be 200 µs. The value that you specify for the Memory initialization time at power up (tINIt) setting in the MegaWizard interface is only used for hardware that you generate. The controller simulation model is created with a much shorter t

time to make simulation easier.

INIT

3–6 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

clk

ddr_cke

ddr_a

ddr_ba

ddr_cs_n

ddr_ras_n

ddr_cas_n

ddr_we_n

local_init_done

0 0

0 1 01

0 0 0 0 0 0 00

[1] [2] [3] [4] [6][5][5]

200 clock cycles

Key: P = PCH L = LMR A = ARF

DDR Command P L L P A A LL

Initialization Timing

1 Do not set tINIT to zero.

Figure 3–4. DDR SDRAM Device Initialization Timing

The following sequence corresponds with the numbered items in Figure 3–4.

1. A PCH command is sent to all banks by setting the precharge pin, the address bit a[10], or a[8] high.

2. An ELMR command is issued to enable the internal delay-locked loop (DLL) in the memory devices. An ELMR command is an LMR command with the bank address bits set to address the extended mode register.

3. An LMR command sets the operating parameters of the memory such as CAS latency and burst length. This LMR command also resets the internal memory device DLL. The DDR SDRAM high-performance controller allows 200 clock cycles to elapse after a DLL reset and before it issues the next command to the memory.

4. A further PCH command places all the banks in their idle state.

5. Two ARF commands must follow the PCH command.

6. The final LMR command programs the operating parameters without resetting the DLL.

After issuing the final LMR command, the memory controller hands over control of the memory to the ALTMEMPHY megafunction to allow it to carry out its calibration process.

When the ALTMEMPHY megafunction has finished calibrating, the memory controller asserts the local_init_done signal, which shows that it has initialized the memory devices.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–7

Key: P = PCH L = LMR A = ARF

clk

ddr_cke

ddr_a

ddr_ba

ddr_cs_n

ddr_ras_n

ddr_cas_n

ddr_we_n

local_init_done

DDR Command

2 0 3 0 1 0 0 1 0 1 11

0 0 0 0 0 0 0

P L L L L P A A L N L LL

200 clock cycles

[1] [2] [3] [3] [4] [7][6][5] [7] [8] [9]

Initialization Timing

DDR2 SDRAM Initialization Timing

The DDR2 SDRAM high-performance controller initializes the memory devices by issuing the following command sequence:

■ NOP (for 200 µs, programmable)

■ PCH

■ ELMR, register 2

■ ELMR, register 3

■ ELMR, register 1

■ LMR

■ PCH

■ ARF

■ LMR

■ ELMR, register 1

Figure 3–5 shows a typical DDR2 SDRAM initialization timing sequence, which is

described below. The length of time between the reset and the clock enable signal going high should be 200 µs. The value that you choose for the Memory initialization time at power up (tINIt) setting in the MegaWizard interface is only used for hardware that you generate. The controller simulation model is created with a much shorter t

time to make simulation easier.

INIT

Figure 3–5. DDR2 SDRAM Device Initialization Timing

Note to Figure 3–5:

(1) local_init_done only goes high when calibration has completed.

3–8 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

Initialization Timing

The following sequence corresponds with the numbered items in Figure 3–5 on

page 3–7.

1. The clock enable signal (CKE) is asserted 200 µs after coming out of reset.

2. The controller then waits 400 ns and then issues the first PCH command by setting the precharge pin, the address bit a[10] or a[8] high. The 400 ns is calculated by taking the number of clock cycles calculated by the wizard for the 200 µs delay and dividing this by 500. If a small initialization time is selected for simulation purposes, this delay is always at least 1 clock cycle.

3. Two ELMR commands are issued to load extend mode registers 2 and 3 with zeros.

4. An ELMR command is issued to extend mode register 1 to enable the internal DLL in the memory devices.

5. An LMR command is issued to set the operating parameters of the memory such as CAS latency and burst length. This LMR command is also used to reset the internal memory device DLL.

6. A further PCH command places all the banks in their idle state.

7. Two ARF commands must follow the PCH command.

8. A final LMR command is issued to program the operating parameters without resetting the DLL.

9. 200 clock cycles after step 5, two ELMR commands are issued to set the memory device off-chip driver (OCD) impedance to the default setting.

After issuing the final ELMR command, the memory controller hands over control of the memory to the ALTMEMPHY megafunction to allow it to carry out its calibration process.

When ALTMEMPHY megafunction has finished calibrating, the memory controller asserts the local_init_done signal, which shows that it has initialized the memory devices.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–9

ALTMEMPHY Signals

This section describes the ALMEMPHY megafunction signals for the following interfaces:

■ DDR2 and DDR SDRAM signals

■ QDR II+ and QDR II SRAM signals

DDR2 and DDR SDRAM Signals

Tab le 3– 1 through Table 3–10 show the signals for DDR2 and DDR SDRAM nonAFIs.

The signal lists include the following signal groups:

■ I/O interface to the external memory device

■ Clock and reset signals

■ PLL reconfiguration signals

■ External DLL signals

■ User-mode calibrated on-chip termination (OCT) control signals

■ Interface to the memory controller

■ Local interface signals

■ Datapath interface for the controller

■ ALTMEMPHY megafunction calibration status interface

■ Additional calibration signals from the sequencer

1 Ports with the prefix “mem_” connect the PHY with the memory device; ports with the

prefix “ctl_” connect the PHY with the controller. Ports with prefix “ctl_mem_” indicate the datapath for the controller; ports with the prefix “local_” indicate the signal to be connected with the example driver or user logic.

1 Signals with suffix _n are active low; signals without suffix _n are active high.

Table 3–1. I/O Interface for DDR2 and DDR SDRAM—nonAFI (Note 1) (Part 1 of 2)

Signal Name Type Width Description

mem_addr output MEM_IF_ROWADDR_WIDTH The memory row and column address bus.

mem_ba output MEM_IF_BANKADDR_WIDTH The memory bank address bus.

mem_cas_n output 1 The memory column address strobe.

mem_cke output MEM_IF_CS_WIDTH The memory clock enable.

mem_clk bidir MEM_IF_CLK_PAIR_COUNT The memory clock, positive edge clock. (2)

mem_clk_n bidir MEM_IF_CLK_PAIR_COUNT The memory clock, negative edge clock. (2)

mem_cs_n output MEM_IF_CS_WIDTH The memory chip select signal.

mem_dm output MEM_IF_DM_WIDTH The optional memory data mask bus.

mem_dq bidir MEM_IF_DWIDTH The memory bidirectional data bus.

mem_dqs bidir MEM_IF_DWIDTH /

The memory bidirectional data strobe bus.

MEM_IF_DQ_PER_DQS

3–10 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

ALTMEMPHY Signals

Table 3–1. I/O Interface for DDR2 and DDR SDRAM—nonAFI (Note 1) (Part 2 of 2)

Signal Name Type Width Description

mem_dqsn bidir MEM_IF_DWIDTH /

MEM_IF_DQ_PER_DQS

The memory bidirectional data strobe bus. Not used in Arria GX, HardCopy II, Stratix II, and Stratix II GX designs.

mem_odt output MEM_IF_CS_WIDTH The memory on-die termination control signal.

mem_ras_n output 1 The memory row address strobe.

mem_reset_n output 1 The memory-reset signal.

mem_we_n output 1 The memory write-enable signal.

Notes to Table 3–1:

(1) Connected to I/O pads. (2) Output is for memory device, and input path is fed back to ALTMEMPHY megafunction for VT tracking.

Table 3–2. Clock and Reset Signals for DDR2/DDR SDRAM—nonAFI (Note 1) (Part 1 of 2)

Signal Name Type Width Description

global_reset_n (1) input 1 The asynchronous reset input to the controller. All other

reset signals are derived from resynchronized versions of this. This signal holds the complete ALTMEMPHY megafunction, including the PLL, in reset while low.

soft_reset_n (1) input 1 The asynchronous reset input to reset controller, for

SOPC Builder use, or to be controlled by other system reset logic. This signal causes a complete reset of the PHY, but not the PLL in the PHY. In Arria GX, Stratix II, and Stratix II GX devices, this signal also resets the PLL reconfiguration block on a falling-edge detection.

phy_clk output 1 The ALTMEMPHY megafunction half-rate clock provided

to the user. All user inputs and outputs to the ALTMEMPHY megafunction are synchronous to this clock in half-rate designs. However, this clock is not used in full-rate designs.

pll_ref_clk input 1 The reference clock input to PLL.

reset_phy_clk_n (1) output 1 Asynchronous reset, that is de-asserted synchronously

with respect to the associated phy_clock clock domain. Use this to reset any additional user logic on that clock domain.

reset_request_n (1) output 1 Directly connected to the locked output of the PLL and is

intended for optional use either by automated tools such as SOPC Builder or could be manually ANDed with any other system-level signals and combined with any edge detect logic as required and then fed back to the global_reset_n input.

Reset request output that indicates when the PLL outputs are not locked. Use this as a reset request input to any system-level reset controller you may have. This signal is always low while the PLL is locking (but not locked), and so any reset logic using it is advised to detect a reset request on a falling-edge rather than by level detection.

aux_half_rate_clk output 1 A copy of the phy_clk_1x signal that you can use in

other parts of your design, same as phy_clk port.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–11

ALTMEMPHY Signals

Table 3–2. Clock and Reset Signals for DDR2/DDR SDRAM—nonAFI (Note 1) (Part 2 of 2)

Signal Name Type Width Description

aux_full_rate_clk output 1 A copy of the mem_clk_2x signal that you can use in

other parts of your design.

Note to Table 3–2:

(1) Refer to Figure 4–3 for the reset mechanism in Arria GX, Cyclone III, Stratix II and Stratix II GX devices.

The ports in Ta bl e 3 –3 exists for all DDR2/DDR SDRAM variations.

Table 3–3. PLL Reconfiguration Signals for DDR2 and DDR SDRAM—nonAFI

Signal Name Type Width Description

pll_reconfig_ enable

input 1 Allows access to the PLL reconfiguration block. Hold this

signal low in normal operation. While the ALTMEMPHY is held in reset (via the soft_reset_n signal), and the reset_request_n signal is 1, it is safe to reconfigure the PLL. To reconfigure the PLL, set this signal to 1 and use the other pll_reconfig signals to access the PLL. When finished reconfiguring, set this signal to 0, and then set the soft_reset_n signal to 1 to bring the ALTMEMPHY out of reset. For this signal to work, the

PLL_RECONFIG_PORTS_EN parameter must be set to TRUE.

pll_reconfig_ write_param

pll_reconfig_read _param

input 1 For more information, refer to the Phase-Locked Loop

(ALTPLL_RECONFIG) User Guide.

input 1 For more information, refer to the Phase-Locked Loop

(ALTPLL_RECONFIG) User Guide.

pll_reconfig input 1 For more information, refer to the Phase-Locked Loop

(ALTPLL_RECONFIG) User Guide.

pll_reconfig_ counter_type

pll_reconfig_ counter_param

pll_reconfig_data _in

pll_reconfig_soft _reset_en_n

input 4 For more information, refer to the Phase-Locked Loop

(ALTPLL_RECONFIG) User Guide.

input 3 For more information, refer to the Phase-Locked Loop

(ALTPLL_RECONFIG) User Guide.

input 9 For more information, refer to the Phase-Locked Loop

(ALTPLL_RECONFIG) User Guide.

input 1 The asynchronous reset input to the PLL reconfiguration

block. This reset causes a PLL reconfiguration block reset and holds the reset if the ALTMEMPHY megafunction in reset while the signal is low. This port only exists in the DDR2/DDR SDRAM variation for Arria GX, Stratix II, and Stratix II GX devices.

pll_reconfig_busy output 1 For more information, refer to the Phase-Locked Loop

(ALTPLL_RECONFIG) User Guide.

pll_reconfig_data _out

output 9 For more information, refer to the Phase-Locked Loop

(ALTPLL_RECONFIG) User Guide.

pll_reconfig_clk output 1 Synchronous clock to use for any logic accessing the PLL

reconfiguration interface.

pll_reconfig_ reset

output 1 Resynchronized reset to use for any logic accessing the PLL

reconfiguration interface.

3–12 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

ALTMEMPHY Signals

Table 3–4. External DLL Signals for DDR2 and DDR SDRAM—nonAFI

Signal Name Type Width Description

dqs_delay_ctrl_ export

output 6 Allows sharing DLL in this ALTMEMPHY instance with another

ALTMEMPHY instance. Connect the dqs_delay_ctrl_export port on the ALTMEMPHY instance with a DLL to the dqs_delay_ctrl_import port on the other ALTMEMPHY instance.

dqs_delay_ctrl_ import

input 6 Allows the use of DLL in another ALTMEMPHY instance in this

ALTMEMPHY instance. Connect the dqs_delay_ctrl_export port on the ALTMEMPHY instance with a DLL to the dqs_delay_ctrl_import port on the other ALTMEMPHY instance.

dll_reference_ clk

output 1 Reference clock to feed to an externally instantiated DLL. This

clock is typically from one of the PHY PLL outputs.

The ports listed in Ta bl e 3 –5 only exist when you target Stratix III and Stratix IV devices. You can leave them unconnected if you are not using user-mode calibrated OCT. For more information about StratixIII and StratixIV ports, refer to

ALTMEMPHY Signals section in chapter 5 of the DDR and DDR2 SDRAM

High-Performance Controllers and ALTMEMPHY IP User Guide.

Table 3–5. User-Mode Calibrated OCT Control Signals for DDR2/DDR SDRAM—nonAFI (Note 1), (2)

Signal Name Type Width Description

oct_ctl_rs_value input 14 Specifies serial termination value. Connects to the

seriesterminationcontrol bus of the ALT_OCT

megafunction. This port exists when you target Stratix IV and Stratix III devices only.

oct_ctl_rt_value input 14 Specifies parallel termination value. Connects to the

parallelterminationcontrol bus of the ALT_OCT

megafunction. This port exists when you target Stratix IV and Stratix III devices only.

Notes to Table 3–5:

(1) These ports are available if you want to use user-mode OCT calibration. Otherwise, they can be left unconnected. (2) For more information on OCT, see the ALT_OCT Megafunction User Guide.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–13

ALTMEMPHY Signals

Table 3–6. Interface to the Memory Controller for DDR2 and DDR SDRAM—nonAFI (Note 1) (Part 1 of 3)

Signal Name Type Width Description

ctl_add_1t_ac_lat input 1 When asserted, one extra address and command

clock cycle (1T) of latency is inserted in the address and command path if the ADDR_CMD_ADD_1T parameter is set to EXT_SELECT, see “Handshake

Mechanism Between Write Commands and Write Data” on page 3–49.

For DDR SDRAM, the write latency is fixed at one memory clock cycle, but for DDR2 SDRAM, this value changes with the read CAS latency. As the controller is running at half the rate of the memory clock, a latency change of one controller clock cycle is two memory clock cycles. The ALTMEMPHY megafunction allows you to dynamically insert an extra memory clock of delay in the address and command path to compensate.

The insertion of delay is controlled by the

ADDR_CMD_ADD_1T parameter and the ctl_add_1t_ac_lat signal. If ADDR_CMD_ADD_1T is set to the string EXT_SELECT, an extra cycle of latency can be

dynamically inserted on the address and command outputs by asserting the ctl_add_1t_ac_lat input, which allows run-time control of the address and command latency. If ADDR_CMD_ADD_1T is set to the string value TRUE, the extra clock cycle of latency is always present. If it is set to the string value FALSE, the extra latency is never added.

ctl_add_intermediate_ regs

Input 1 When asserted, an additional intermediate register or

registers is included in the address and command path if the ADDR_CMD_ADD_INTERMEDIATE_REGS parameter is set to EXT_SELECT.

For Stratix II and Cyclone III devices only, to maintain the clock cycle relationship between address/command and the write data. You must include the address/command phases where required.

ctl_address output LOCAL_IF_

AWIDTH

The address corresponding to a write or read request. The ALTMEMPHY sequencer logic drives ctl_address during calibration. ctl_address has the same timing as local_address.

ctl_be output LOCAL_IF_

DWIDTH/8

The output to the controller indicating the byte-enable flags. The ALTMEMPHY sequencer logic drives ctl_be during calibration. ctl_be is mandatory and has the same timing as local_be.

3–14 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

ALTMEMPHY Signals

Table 3–6. Interface to the Memory Controller for DDR2 and DDR SDRAM—nonAFI (Note 1) (Part 2 of 3)

Signal Name Type Width Description

ctl_doing_rd input 1 The active-high signal from the controller specifying

that a read command has been issued to the external RAM.

For more information, see “Handshake Mechanism

Between Read Commands and Read Data” on page 3–47.

ctl_init_done input 1 The memory controller drives this active-high signal

to specify that the controller has initialized the memory and the calibration process should begin.

ctl_negedge_en input 1 This signal is used if ADDR_CMD_NEGEDGE_EN is

set to EXT_SELECT. If true, the address and command signals are output on the falling edge of the address and command clock, ac_clk_2x. If false, the address and command signals are output on the rising edge of the address and command clock. When set to EXT_SELECT, the ctl_negedge_en top level input determines whether the edge is used.

ctl_read_req output 1 The active-high signal requesting a read command to

the address on the ctl_address bus.

ctl_ready input 1 The controller-ready signal which indicates that the

currently asserted read or write request has been accepted. The address of the request is sampled when both the ready and request signals are high.

ctl_size output LOCAL_

BURST_LEN_

BITS

The output to the controller indicating the size (length) of the burst transfer, fixed at 1 for this version.

ctl_usr_mode_rdy output 1 The ALTMEMPHY sequencer logic drives this

active-high signal to specify the ALTMEMPHY has finished its calibration and is ready to accept user read or write requests.

ctl_wdata output LOCAL_IF_

DWIDTH

The write data from the ALTMEMPHY to the controller. The ALTMEMPHY sequencer logic drives ctl_wdata during calibration. ctl_wdata has the same timing as local_wdata.

ctl_wdata_req input 1 The controller-request for write data; not required

when the controller has an Avalon-MM interface.

The memory controller that the ALTMEMPHY sequencer uses during calibration drives

ctl_wdata_req. Same timing as local_wdata_req.

ctl_write_req output 1 The active-high signal specifying that a write

command should be issued to the address on the ctl_address signal. The ALTMEMPHY sequencer logic drives ctl_write_req during calibration. Same timing as local_write_req.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–15

ALTMEMPHY Signals

Table 3–6. Interface to the Memory Controller for DDR2 and DDR SDRAM—nonAFI (Note 1) (Part 3 of 3)

Signal Name Type Width Description

ctl_refresh_ack input 1 The active-high valid signal from the controller

acknowledging the refresh request. The ALTMEMPHY sequencer logic uses

ctl_refresh_ack during calibration.

ctl_refresh_req output 1 The output to the controller requesting a refresh.

Same timing as local_refresh_req.

ctl_burstbegin output 1 The output to the controller indicating the start of a

burst. Only available for the Avalon-MM interface.

ctl_rdata input LOCAL_IF_

DWIDTH

The read data from the controller. The ALTMEMPHY sequencer logic uses ctl_rdata during calibration. ctl_rdata has the same timing as

local_rdata.

ctl_rdata_valid input 1 The active-high valid signal for the controller read

data. Asserted coincident with the read data on

ctl_rdata. The controller drives ctl_rdata_valid and has the same timing as local_rdata_valid.

ctl_add_1t_odt_lat input 1 When asserted, one extra address and command

clock cycle (1T) of latency is inserted in the address and command ODT path if ODT_ADD_1T is set to EXT_SELECT, see “Handshake Mechanism

Between Write Commands and Write Data” on page 3–49.

The timing of the mem_odt signal can be controlled in the same way as mem_addr, but is independent of the address and command latency. If the ODT_ADD_1T parameter is set to EXT_SELECT, an extra cycle of latency can be dynamically inserted on the ODT command outputs by asserting the ctl_add_1t_odt_lat input, which allows separate run-time control of the latency of the ODT signal. If ODT_ADD_1T is set to TRUE, the extra clock cycle of latency is always present. If ODT_ADD_1T is set to FALSE, the extra latency is never added.

ctl_rlat output READ_LAT_

WIDTH

Unused port that exists when you target Stratix IV and Stratix III devices. The default

READ_LAT_WIDTH is set to 4.

ctl_self_rfsh_ack input 1 Signal from the Altera high-performance controller

ctl_powerdn_ack input 1

that is passed through the PHY.

ctl_autopch_req output 1

ctl_powerdn_req output 1

ctl_self_rfsh_req output 1

Note to Table 3–6:

(1) Interface signals to the controller either through the sequencer or user interface.

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Table 3–7. Local Interface Signals for DDR2 and DDR SDRAM—nonAFI (Part 1 of 2) (Note 1)

Signal Name Type Width Description

local_address input LOCAL_IF_

AWIDTH

local_be input LOCAL_IF_

DWIDTH / 8

The address corresponding to a write or read request.

The input to ALTMEMPHY megafunction indicating the byte-enable flags.

local_read_req input 1 The active-high signal requesting a read command

to the address on the ctl_address bus.

local_ready output 1 The controller-ready signal which indicates that the

currently asserted read or write request has been accepted. The address of the request is sampled when both the ready and request signals are high.

local_size input LOCAL_

BURST_LEN_

The controller signal to indicate the size (length) of the burst transfer, fixed at 1 for this version.

BITS

local_wdata input LOCAL_IF_

DWIDTH

The write data from the user to the ALTMEMPHY megafunction.

local_wdata_req output 1 The controller request for write data; not required

when the controller has an Avalon-MM interface.

local_write_req input 1 The active-high signal specifying that a write

command should be issued to the address on the

ctl_address signal.

local_refresh_req input 1 The ALTMEMPHY megafunction receives refresh

requests from the local interface and passes them to the controller via ctl_refresh_req when in user mode (ctl_usr_mode output is high).

local_burstbegin input 1 The ALTMEMPHY megafunction receives the

burstbegin signal from the local interface and

passes it to the controller via ctl_burstbegin when in user mode (ctl_usr_mode output is high).

local_rdata output LOCAL_IF_

DWIDTH

When ctl_usr_mode is high, this output passes through the read data from the controller to the local interface. Otherwise, it is tied low.

local_rdata_valid output 1 When ctl_usr_mode is high, this output passes

through the read data valid signal (ctl_rdata_valid) from the controller to the local interface. Otherwise, it is driven low.

local_init_done output 1 When ctl_usr_mode is high, this output passes

through the controller’s initialization done signal (ctl_init_done) from the controller to the local interface. Otherwise, it is driven low.

local_refresh_ack output 1 When ctl_usr_mode is high, this output passes

through the controller’s refresh acknowledge signal (ctl_refresh_ack) from the controller to the local interface. Otherwise, it is driven low.

local_autopch_req input 1 User control for auto precharge to request the

controller to issue an autoprecharge write or autoprecharge read command.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–17

ALTMEMPHY Signals

Table 3–7. Local Interface Signals for DDR2 and DDR SDRAM—nonAFI (Part 2 of 2) (Note 1)

Signal Name Type Width Description

local_powerdn_req input 1 User control to power down the memory device to

request the controller to place the memory devices into a power-down state as soon as it can without violating the relevant timing parameters and responds by asserting the local_powerdn_ack signal.

local_self_rfsh_req input 1 User control of the self-refresh feature to request

that the controller place the memory devices into a self-refresh state by asserting this signal.

local_self_rfsh_ack output 1 Self-refresh request acknowledge signal. This signal

is asserted and deasserted in response to the

local_self_rfsh_req signal from the user.

local_powerdn_ack output 1 Power-down request acknowledge signal. This

signal is asserted and deasserted in response to the local_powerdn_req signal from the user.

Note to Table 3–7:

(1) Passed through PHY to the controller.

Table 3–8. Datapath Interface for DDR2 and DDR SDRAM—nonAFI (Part 1 of 3) (Note 1)

Signal Name Type Width Description

ctl_mem_addr_h (1) input MEM_IF_

ROWADDR_

WIDTH

The row or column address that is sent to the external memory. Output during the high halfperiod of the address and command clock and driven by the memory controller.

ctl_mem_addr_l (1) input MEM_IF_

ROWADDR_

WIDTH

The row or column address that is sent to the external memory. Output during the low half-period of the address and command clock and driven by the memory controller.

ctl_mem_ba_h (1) input MEM_IF_

BANKADDR_

WIDTH

The bank address that is sent to the external memory. Output during the high half-period of the address and command clock and driven by the memory controller.

ctl_mem_ba_l (1) input MEM_IF_

BANKADDR_

WIDTH

The bank address that is sent to the external memory. Output during the low half-period of the address and command clock and driven by the memory controller.

ctl_mem_be input LOCAL_IF_

DWIDTH/8

The optional byte-enable signals for the write data to the external memory. The ALTMEMPHY megafunction converts the byte enables into memory mem_dm signals. If mem_dm pins are not required (mem_dm_pins set to FALSE), the mem_dm logic is not generated and the mem_dm pins are not instantiated.

ctl_mem_cas_n_h (1) input 1 The column-address strobe signal from the

controller to the memory. Output during the high half-period of the address and command clock and driven by the memory controller.

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ALTMEMPHY Signals

Table 3–8. Datapath Interface for DDR2 and DDR SDRAM—nonAFI (Part 2 of 3) (Note 1)

Signal Name Type Width Description

ctl_mem_cas_n_l (1) input 1 The column-address strobe signal from the

controller to the memory. Output during the low half-period of the address and command clock and driven by the memory controller.

ctl_mem_cke_h (1) input MEM_IF_CS_

WIDTH

The clock-enable signal from the controller to the memory. Output during the high half-period of the address and command clock and driven by the memory controller.

ctl_mem_cke_l (1) input MEM_IF_CS_

WIDTH

The clock-enable signal from the controller to the memory. Output during the low half-period of the address and command clock and driven by the memory controller.

ctl_mem_cs_n_h (1) input MEM_IF_CS_

WIDTH

The chip-select signal from the controller to the memory. For half-rate designs, always tie ctl_mem_cs_n_h high, as even with 2T addressing, the chip select is only driven for the second clock cycle, to allow an extra clock cycle of setup time for the other address and command signals. Output during the high half-period of the address and command clock and driven by the memory controller

ctl_mem_cs_n_l (1) input MEM_IF_CS_

WIDTH

The chip-select signal from the controller to the memory. Output during the low half-period of the address and command clock and driven by the memory controller.

ctl_mem_dqs_burst input 1 Controls the DQS output enables of the DQS pins.

ctl_mem_odt_h (1) input MEM_IF_CS_

WIDTH

ctl_mem_odt_l (1) input MEM_IF_CS_

WIDTH

The on-die termination signal from the controller to the memory.

ctl_mem_ras_n_h (1) input 1 The row-address strobe signal from the controller

to the memory. Output during the high half-period of the address and command clock and driven by the memory controller.

ctl_mem_ras_n_l (1) input 1 The row-address strobe signal from the controller

to the memory. Output during the low half-period of the address and command clock and driven by the memory controller.

ctl_mem_rdata output LOCAL_IF_

DWIDTH

ctl_mem_rdata_valid output 1

The ctl_mem_rdata signal is the captured, resynchronized, and demultiplexed read data from the ALTMEMPHY megafunction to the controller.

The ctl_mem_rdata_valid signal Indicates when the ctl_mem_rdata is valid.

For more information, see “Handshake Mechanism

Between Read Commands and Read Data” on page 3–47.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–19

ALTMEMPHY Signals

Table 3–8. Datapath Interface for DDR2 and DDR SDRAM—nonAFI (Part 3 of 3) (Note 1)

Signal Name Type Width Description

ctl_mem_wdata input MEM_IF_

DWIDTH× DWIDTH_

RATIO

The write data bus, which has valid data in the same clock cycles that control_wdata_valid is asserted, see “Handshake Mechanism Between

Read Commands and Read Data” on page 3–47.

ctl_mem_wdata_valid input 1 Generates the mem_dq output enable. When

asserted, the ctl_mem_rdata_valid signal indicates that the coincident read data on

ctl_mem_rdata is valid.

ctl_mem_we_n_h (1) input 1 The write-enable signal from the controller to the

memory. Output during the high half-period of the address and command clock and driven by the memory controller.

ctl_mem_we_n_l (1) input 1 The write-enable signal from the controller to the

memory. Output during the low half-period of the address and command clock and driven by the memory controller.

Note to Table 3–8:

(1) The “_h” and “_l” stand for high and low. They signify in which half of the clock cycle the data is output. The _h data is output when the

corresponding clock, for example ac_clk_2x, is high. The _l data is output when the ac_clk_2x clock is low. The signals with _h and _l allow you to select between 1T and 2T addressing. For half-rate designs, 1T is where the address and command signals are driven for one clock; 2T is where they are driven for 2 clocks. For full-rate designs, ensure the same signal drives both _h and _l signals and 2T addressing is used. Also when high-performance controllers use ALTMEMPHY, 2T addressing is used.

Table 3–9. Calibration Status Interface for DDR2 and DDR SDRAM—nonAFI

Signal Name Type Width Description

resynchronisation_ successful

output 1 Active-high signal that is set to indicate that

calibration of the read data resynchronization clock phase was completed and successful.

postamble_successful output 1 Active-high signal that is set to indicate that read

postamble calibration was completed.

tracking_successful output 1 Active-high signal that is set to indicate the

completion of mimic path VT variation tracking operation.

tracking_adjustment_ up

output 1 Active-high signal that is pulsed to indicate that the

mimic path tracking has adjusted the resynchronization clock phasing upwards.

tracking_adjustment_ down

output 1 Active-high signal that is pulsed to indicate that the

mimic path tracking has adjusted the resynchronization clock phasing downwards.

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ALTMEMPHY Signals

Tab le 3– 10 shows additional calibration status signal outputs from the sequencer. You

can either pull these signals out to the top level or observe them through the SignalTap

II logic analyzer.

Table 3–10. Additional Calibration Status Signals—nonAFI

Signal Description

rsu_codvw_phase

(Center of data valid window)

The ALTMEMPHY resynchronization setup unit (RSU) sweeps the phase of a resynchronization clock across 360° (full-rate designs) or 720° (half-rate designs) of a memory clock cycle. Data reads from the DIMM are performed for each phase position and a data valid window is located, which is the set of resynchronization clock phase positions where data is successfully read. The final resynchronization clock phase is set at the center of this range: the center of the data valid window (CODVW). This output is set to the current calculated value for the CODVW and represents how many phase steps were performed by the PLL to offset the resynchronization clock from the memory clock.

rsu_read_latency

(Read latency at the center of the window)

rsu_no_dvw_err

(Calibration failed due to no window

If the RSU can find one data valid window (and not more than one), the resynchronization clock is positioned at the center and the rsu_read_latency output is then set to the read latency (in phy_clk cycles) using that resynchronization clock phase. If calibration is unsuccessful, this signal remains at 0.

If the RSU sweeps the resynchronization clock across every phase and does not see any valid data at any phase position, calibration fails and this output is set to 1.

found)

rsu_grt_one_dvw_err

(Calibration failed due to more than one valid window)

rsu_multiple_valid_ latencies_err

If the RSU sweeps the resynchronization clock across every phase and sees multiple data valid windows, this indicates unexpected read data (random bit errors) or an incorrectly configured PLL, which must be resolved. Calibration has failed and this output is set to 1.

If the RSU sweeps the resynchronization clock across every phase and sees valid data at more than two different latencies, calibration fails and this output is set to 1.

(Calibration failed due to more than two read latencies)

QDR II+/QDR II SRAM Signals

This section describes the ALMEMPHY megafunction signals for QDR II+/QDR II SRAM.

Tab le 3– 11 through Table 3–15 show the signals.

1 Signals with the prefix mem_ connect the PHY with the memory device; signals with

the prefix ctl_ connect the PHY with the controller.

Table 3–11. I/O Interface to QDR II+/QDR II SRAM (Note 1) (Part 1 of 2)

Signal Name Type Width Description

mem_addr output MEM_IF_ROWADDR_

WIDTH

mem_clk output MEM_IF_CLK_PAIR

_COUNT

mem_clk_n output MEM_IF_CLK_PAIR

_COUNT

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Memory address bus.

Memory clock, positive edge clock (K).

Memory clock, positive edge clock (K#) 180° offset from mem_clk.

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–21

ALTMEMPHY Signals

Table 3–11. I/O Interface to QDR II+/QDR II SRAM (Note 1) (Part 2 of 2)

Signal Name Type Width Description

mem_d output MEM_IF_DWIDTH Memory data bus. D input to QDR II SRAM device.

mem_dm output MEM_IF_DM_WIDTH Memory write select. BWS# input to QDR II SRAM

device.

mem_dq input MEM_IF_DWIDTH Memory data bus. Q output from QDR II SRAM

device.

mem_dqs input MEM_IF_DWIDTH /

Memory read clock high bits (CQ).

MEM_IF_DQ_PER_

DQS

mem_dqsn input MEM_IF_DWIDTH /

Memory read clock low bits (CQn).

MEM_IF_DQ_PER_

DQS

mem_doff_n output 1 Memory DLL disable control.

mem_rps_n output MEM_IF_CS_WIDTH Memory read enable signal.

mem_wps_n output MEM_IF_CS_WIDTH Memory write enable signal.

Note to Table 3–11:

(1) Connected to WYSIWYGS/pad atoms.

Table 3–12. Clock and Reset Signals for QDR II+/QDR II SRAM (Part 1 of 2)

Signal Name Type Width Description

global_reset_n (1) input 1 The asynchronous reset input to the controller. All other

reset signals are derived from resynchronized versions of this. This signal holds the complete ALTMEMPHY megafunction, including the PLL, in reset while low.

soft_reset_n (1) input 1 The asynchronous reset input to reset controller, for

phy_clk output 1 The ALTMEMPHY megafunction half-rate clock provided

to the user. All user inputs and outputs to the ALTMEMPHY megafunction are synchronous to this clock in half-rate designs. However, this clock is not used in full-rate designs.

pll_ref_clk input 1 The reference clock input to PLL.

reset_phy_clk_n (1) output 1 Asynchronous reset, that is de-asserted synchronously

with respect to the associated phy_clock clock domain. Use this to reset any additional user logic on that clock domain.

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ALTMEMPHY Signals

Table 3–12. Clock and Reset Signals for QDR II+/QDR II SRAM (Part 2 of 2)

Signal Name Type Width Description

reset_request_n (1) output 1 Directly connected to the locked output of the PLL and is

aux_half_rate_clk output 1 A copy of the phy_clk_1x signal that you can use in

other parts of your design, same as phy_clk port.

aux_full_rate_clk output 1 A copy of the mem_clk_2x signal that you can use in

other parts of your design.

Note to Table 3–2:

(1) Refer to Figure 4–3 for the reset mechanism in Arria GX, Stratix II and Stratix II GX devices.

ALTMEMPHY Signals section in chapter 5 of the DDR and DDR2 SDRAM

High-Performance Controllers and ALTMEMPHY IP User Guide.

Table 3–13. User-Mode Calibrated OCT Control Signals for QDR II+/QDR II SRAM (Note 1), (2)

Signal Name Type Width Description

oct_ctl_rs_value input 14 Specifies serial termination value. Connects to the

seriesterminationcontrol bus of the ALT_OCT

megafunction. This port exists when you target Stratix IV and Stratix III devices only.

oct_ctl_rt_value input 14 Specifies parallel termination value. Connects to the

parallelterminationcontrol bus of the ALT_OCT

megafunction. This port exists when you target Stratix IV and Stratix III devices only.

Notes to Table 3–5:

(1) These ports are available if you want to use user-mode OCT calibration. Otherwise, they can be left unconnected. (2) For more information on OCT, see the ALT_OCT Megafunction User Guide.

Table 3–14. Datapath Interface for QDR II+/QDR II SRAM (Note 1) (Part 1 of 2)

Signal Name Type Width Description

ctl_mem_addr_h input MEM_IF_

ROWADDR_WIDTH

ctl_mem_addr_l input MEM_IF_

ROWADDR_WIDTH

Write address from the controller to the external memory.

Read address from the controller to the external memory.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–23

ALTMEMPHY Signals

Table 3–14. Datapath Interface for QDR II+/QDR II SRAM (Note 1) (Part 2 of 2)

Signal Name Type Width Description

ctl_mem_be input LOCAL_IF_

DWIDTH ×

DWIDTH_

RATIO

Optional byte enable signals for the write data to the external memory. The PHY converts the byte enables into memory DM signals. If DM pins are not required (MEM_DM_PINS set to FALSE), the DM logic is not generated and the DM pins are not instantiated.

ctl_mem_wdata input MEM_IF_

DWIDTH *

DWIDTH_

The write data bus, which has valid data in the same clock cycles that control_wdata_valid is asserted.

RATIO

ctl_mem_rdata_valid output 1 Indicates when the ctl_mem_rdata is valid.

ctl_mem_wps_n input MEM_IF_CS_

WIDTH

Write enable signal from the controller to the memory (QDR II SRAM). When this signal is asserted, a write request is issued to the address presented on the ctl_mem_addr_h port.

ctl_mem_rps_n input MEM_IF_CS_

WIDTH

Read enable signal from the controller to the memory (QDR II SRAM). When this signal is asserted, a read request is issued to the address presented on the ctl_mem_addr_l port.

ctl_mem_rdata output LOCAL_IF_

DWIDTH

Captured, resynchronized, and de-multiplexed read data from the PHY to the controller.

ctl_mem_wdata_valid input 1 Generates the DQ output enable.

Note to Table 3–14:

(1) Address and command and wdata/rdata.

Table 3–15. Calibration Status Signals for QDR II+/QDR II SRAM (Note 1)

Signal Name Type Width Description

ctl_usr_mode_rdy output 1 Active high signal specifying the PHY has finished

its calibration and is ready to accept user read or write requests. This signal does not indicate that calibration was successful, so you must check whether resynchronization_successful is high also.

resynchronisation_ successful

output 1 Active high signal that shall be set to indicate that

calibration of the read data resynchronization clock phase was successful.

ctl_rlat output 5 Indicates the read latency of the interface in PHY

clock cycles.

Note to Table 3–15:

(1) Calibration control or passed through from the user interface.

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ALTMEMPHY Signals

Tab le 3– 16 shows the parameters that Table 3–11 through Table 3–15 refer to.

Table 3–16. Parameters

Parameter Name Description

DBG_A_WIDTH —

DQS_DELAY_CTL_WIDTH —

DWIDTH_RATIO The data width ratio from the local interface to the memory interface.

DWIDTH_RATIO of 2 means full rate, while DWIDTH_RATIO of 4 means half rate.

LOCAL_IF_DWIDTH The width of the local data bus must be quadrupled for half-rate and doubled for

full-rate.

MEM_IF_DWIDTH The data width at the memory interface. MEM_IF_DWIDTH can have values that are

multiples of MEM_IF_DQ_PER_DQS.

MEM_IF_DQS_WIDTH The number of DQS pins in the interface.

MEM_IF_ROWADDR_WIDTH The row address width of the memory device.

MEM_IF_BANKADDR_WIDTH The bank address with the memory device (not used in QDR II+/QDR II SRAM

variations).

MEM_IF_CS_WIDTH The number of chip select pins in the interface. The sequencer only calibrates one chip

select pin.

MEM_IF_DM_WIDTH The number of mem_dm pins on the memory interface.

MEM_IF_DQ_PER_DQS The number of mem_dq[] pins per mem_dqs pin.

MEM_IF_CLK_PAIR_COUNT The number of mem_clk/mem_clk_n pairs in the interface.

READ_LAT_WIDTH The bus width for the ctl_rlat signal, used in QDR II+/QDR II SRAM PHY, that

determines the read latency of your system.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–25

Understanding the Testbench

Before the user logic (example driver) can read or write to the local interface, the external SDRAM must first be initialized and calibrated. Following power-up or a reset event, the following stages of operation take place:

■ PLL initialization and lock

■ Memory device initialization

■ Interface training and calibration

■ Write training data

■ Calibration

■ Functional memory use

PLL Initialization and Lock

PLL initialization and lock is the first activity that takes place and completes when the signal pll_locked is first asserted. Typically this stage requires approximately 150 ns, but can take longer if the PLL Option Hold ‘locked’ output low for <user entered number> cycles after the PLL initializes is turned on.

The exact length of time required for pll_locked to become asserted depends on several factors including Device Type, PLL Type, and PLL Configuration.

1 pll_locked is not included in the simulation default waveform view, and must be

added manually.

f For more information, refer to Phase-Locked Loop (ALTPLL) Megafunction User Guide.

Memory Device Initialization

Memory devices must be initialized before functional use. The exact sequence is different for DDR2 and DDR SDRAM. The memory controller sets the operating parameters of the memory based on the parameters you specify in the MegaWizard interface. This parameter is fixed at generation time and is not dynamically editable via the local interface.

Interface Training and Calibration

The sequencer element of the ALTMEMPHY megafunction performs path-delay analysis to correctly set up the resynchronization (DQS mode devices), capture (Non DQS Mode devices) clocks and the data alignment settings. The sequencer issues read and write commands to the memory controller over the ctl_* interface for DDR and DDR2 SDRAM high-performance memory controllers, which is performed in the following two stages:

■ Write training data

■ Calibration

3–26 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

Understanding the Testbench

Write Training Data

A specific pattern of data is written to the memory so that each DQ pin may be calibrated. The same pattern is written to every DQ pin. The pattern takes the form: “10101010_11111111_00000000_11111100” from the lowest address location to the highest address location left to right. Once the memory interface is initialized, a single write transaction is observed to the memory using the pattern above to write the same pattern to each DQ bit.

Calibration

When the write training data process is completed, the sequencer then repeatedly reads the training pattern back from the memory. This action is performed on a per DQ pin basis, and for all available phase steps supported by the PLL configuration.

The sequencer phase steps through 360° for a full rate controller and through 720° for a half rate controller. For simulation purposes only, calibration can be performed on just a single DQ pin, which greatly reduces simulation run time. The sequencer stores a list of pass and fail training pattern results and when all phase comparisons have been made, sets the optimum clock phase to be centered in the available window of results.

Simulation of the calibration cycle cannot be bypassed, but setting it to single bit calibration speeds up the process significantly.

1 The ALTMEMPHY megafunction only the center of data valid window and read

latency. The amount of internal RAM required to store calibration results therefore, is significantly reduced compared to earlier versions. The total calibration time is also reduced.

Functional Memory Use

When training and calibration completes, the ALTMEMPHY sequencer asserts ctrl_usr_mode_rdy to the memory controller, which is then copied to the local interface as the signal local_init_done. Local interface read and write transactions can now occur.

In the example testbench, the example driver now performs 16 writes followed by 16 reads to incremental address locations spanning column, row and bank locations using LFSR pattern based on the address being written.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–27

Functional Simulation—the ModelSim Wave and Transcript Window

To better understand the operation of the ALTMEMPHY megafunction and the memory controllers, identify the various stages of operation, the expected results, and the behavior of the IP. The following sections describe each of these stages in greater detail.

■ “Full Window Stage Identification” on page 3–27

■ “Initialization Stage” on page 3–29

■ “Write Training Data Stage” on page 3–31

■ “Read Calibration Phase” on page 3–33

■ “Functional Memory Use Stage” on page 3–37

Full Window Stage Identification

Figure 3–6 on page 3–28 shows a standard appearance of an example testbench in the

ModelSim

1 The total simulation time around 270 µs to 203 µs is used for the memory initialization

requirements, and in this example 61 µs is used by the calibration routine to calibrate using just a single DQ pin. In general, the PLL initialization phase has negligible impact on the overall simulation time.

-Altera software.

f For further information on simulating the PLL, refer to Phase-Locked Loop (ALTPLL)

Megafunction User Guide.

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3–28 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

Figure 3–6. Example Testbench

Functional Simulation—the ModelSim Wave and Transcript Window

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–29

Functional Simulation—the ModelSim Wave and Transcript Window

Initialization Stage

The full window stage shows that the Memory initialization stage is dominated by the NOP command where t

The exact sequence of commands differs between the various external memory families (refer to the respective the device datasheets for further information). For this DDR2 SDRAM example, the following sequence applies:

is 200 µs.

INIT

1. Issue NOP commands for 200 µs, programmable via t

parameter.

INIT

2. Assert mem_cke (high).

3. Issue a PCH, then wait for 400 ns after t

(400 ns is derived from dividing t

INIT

counter by 500).

4. Issue an LMR command to ELMR register 2 = 0.

5. Issue an LMR command to ELMR register 3 = 0.

6. Issue an LMR command to ELMR register to enable the memory DLL and set Drive strength, AL, RTT, DQS#, RDQS, OE.

7. Issue an LMR command to MR register to reset DLL and set operating parameters.

8. Issue a PCH.

9. Issue an ARF.

10. Issue another ARF.

11. Issue an LMR command to MR register to set operating parameters.

12. Issue an LMR command to ELMR register to set default OCD and parameters. 200 clock cycles after DLL reset, the memory is initialized.

See Figure 3–7 on page 3–30 for the expected waveform view of the initialization phase directly following the NOP of 200 µs. Steps 2 to 9 are expanded to increase detail. Initialization is complete by the second yellow cursor. Additional signals are added to simplify debugging.

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3–30 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

Figure 3–7. DDR2 SDRAM Simulation Initialization Phase

Functional Simulation—the ModelSim Wave and Transcript Window

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–31

Functional Simulation—the ModelSim Wave and Transcript Window

Write Training Data Stage

As shown in Figure 3–8 on page 3–32, following memory initialization, the write data training stage is closely followed by the first read data calibration read sample.

External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide © January 2010 Altera Corporation

3–32 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

Figure 3–8. Writing Data Training

Functional Simulation—the ModelSim Wave and Transcript Window

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–33

Functional Simulation—the ModelSim Wave and Transcript Window

Read Calibration Phase

Figure 3–9 on page 3–34 shows that the read data calibration stage closely follows the

write data stage. The calibration repeatedly performs the following steps:

1. Reads back the data pattern.

2. Records pass/fail.

3. Increments the PLL phase step. (360°/number of phase steps).

4. Repeats.

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3–34 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

Figure 3–9. Read Calibration Phase

Functional Simulation—the ModelSim Wave and Transcript Window

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–35

Functional Simulation—the ModelSim Wave and Transcript Window

This process continues until all 360° (full rate) or 720° (half rate) worth of phases are sampled and the available data window is measured. The length of time between each read is determined by the PLL reconfiguration requirements and the compare and store operation of the sequencer, which is device and configuration dependant. The gap observed between the first and subsequent reads is greater as the sequencer must set the PLL into phase stepping mode.

Once a successful range of phases has been sampled, the sequencer center aligns the PLL phase within this calibrated window. This can be observed on the PLL reconfiguration bus as a burst of phase changes without any read accesses. In the example, this calibration is setting on the capture clock phase, so you would (in a functional simulation) expect a phase of around –90° to be selected. 48 phase steps were reported during the generation, and a burst of 10 PLL reconfigurations can be observed (360/48 * 10 = –75°). Refer to Figure 3–10 on page 3–36.

1 In Arria GX, Stratix II, and Stratix III devices, calibration is performed on the

resynchronization clock.

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3–36 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

Figure 3–10. Calibration Phase - Setting the Optimum Phase

Functional Simulation—the ModelSim Wave and Transcript Window

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–37

Functional Simulation—the ModelSim Wave and Transcript Window

1 Until the completion of the calibration phase, the local interface remains static and all

transactions take place over the control interface. Additional signals of interest are added to the wave view.

1 For simulation purposes, the ALTMEMPHY megafunction allows calibration of a

single DQ pin. If you do not enable this option, then the time required for the calibration phase of the simulation is multiplied by the number of DQ pins used in your actual memory controller instance. To enable this option, select Quick Calibration under Auto-Calibration Simulation Options list at the Memory Settings tab in the Parameter Settings page.

Functional Memory Use Stage

Once the calibration stage completes, indicated by the signals local_init_done and ctl_usr_mode_rdy, then the functional memory use stage begins.

The example driver, which is generated by the MegaWizard Plug-In Manager, is clear text HDL in the language of your choice. It can be used to test a custom controller and ALTMEMPHY megafunction combination. It performs a series of writes to the external memory, followed by a series of reads to the same locations, and compares the read and write data.

This comparison results in dynamic “pass not fail per byte” (pnf_per_byte) signals, and a latched combined pass not fail (pnf, 1=pass 0=fail) signal. Each completed series of writes and reads is signaled via the test_complete signal, and then the test repeats.

1 The example testbench stops when either test_complete is asserted or when

200,000 mem_clk cycles after the t

INIT

time.

In Figure 3–11 on page 3–38, the series of writes followed by reads can be seen on both the local and memory interfaces, together with the test complete signals.

As the data written to the memory is simply an LFSR pattern, the example driver is able to generate expected read data from the memory to compare with that previously written to the same address. The data on the read data bus should match that on the write data bus during the read process.

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3–38 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

Figure 3–11. Functional Memory Use Stage

Functional Simulation—the ModelSim Wave and Transcript Window

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–39

Additional Debug Signals

This section discusses the following debug signals:

■ “PLL and PLL Reconfiguration Signals”

■ “Calibration Status Interface”

■ “Additional Calibration Status Interface Signals”

PLL and PLL Reconfiguration Signals

Before any design operates correctly, all clock and reset signals must be stable and configured correctly. Therefore, you must ensure that the various PLL ports are visible in your simulation. This is of increased values when simulating a DDR and DDR2 SDRAM high-performance memory controller-based design because of the PLL phase calibration stages that occur.

f For full description of each signal, refer to Phase-Locked Loop (ALTPLL) Megafunction

User Guide.

You must add the following ALTMEMPHY signals to your simulation:

■ seq_pll_select

■ phasecounterselect

■ seq_pll_inc_dec_n

■ phaseupdown

■ seq_pll_start_reconfig

■ configupdate

■ pll_reconfig_busy

■ pll_phase_done

■ pll_locked

■ phs_shft_busy

■ pll_reconfig_reset

In Arria GX, Stratix II, and Stratix II GX designs where a separate altpll_reconfig instance is required, the following signals may be added to the simulation:

■ pll_reconfig

■ pll_reconfig_counter_param

■ pll_reconfig_counter_type

■ pll_reconfig_data_in

■ pll_reconfig_enable

■ pll_reconfig_read_param

■ pll_reconfig_soft_reset_en_n

■ pll_reconfig_write_param

3–40 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

■ pll_reconfig_busy

■ pll_reconfig_clk

■ pll_reconfig_data_out

■ pll_reconfig_reset

Additional Debug Signals

1 For full description of the signals listed and their required operation, refer to the

respective Device Handbooks or Phase-Locked Loop Reconfiguration

(ALTPLL_RECONFIG) Megafunction User Guide.

1 The output clock order is fixed in the ALTMEMPHY (seq_pll_select) and a

mapping takes place to align with the required clock port used for each different device family. Refer to <variation name>_phy_alt_mem_phy.v(hd) file and refer to the section that starts with the following code:

// NB This lookup table shall be different for CIII/SIII // The PLL phasecounterselect is 3 bits wide, therefore hardcode the output to 3 bits:

Calibration Status Interface

The following calibration signals provide information for ALTMEMPHY megafunction:

■ ctl_cal_success indicates calibration success

■ ctl_cal_fail indicates calibration failure

Additional Calibration Status Interface Signals

Add the signals in Table 3–17 to your simulation to provide additional information about calibration status:

Table 3–17. Signals for Calibration Status

Signal Description

rsu_codvw_phase

(Center of data valid window)

rsu_read_latency

(Read latency at the center of the window)

rsu_no_dvw_err

(Calibration failed due to no window found)

The ALTMEMPHY resynchronization setup unit (RSU) sweeps the phase of a resynchronization clock across 360° (full-rate mode) or 720° (half-rate mode) of a memory clock cycle. Data reads from the DIMM are performed for each phase position, and a data valid window is located, which is the set of resynchronization clock phase positions where data is successfully read. The final resynchronization clock phase is set at the center of this range: the center of the data valid window or CODVW. This output is set to the current calculated value for the CODVW, and represents how many phase steps were performed by the PLL to offset the resynchronization clock from the memory clock.

If the RSU can find one data valid window (and not more than one) then the resynchronization clock is positioned at the center and the rsu_read_latency output is then set to the read latency (in phy_clk cycles) using that resynchronization clock phase. If calibration is unsuccessful then this signal remains at 0.

If the RSU sweeps the resynchronization clock across every phase and does not see any valid data at any phase position, then calibration fails and this output is set to 1.

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Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–41

Design Considerations

Table 3–17. Signals for Calibration Status

Signal Description

rsu_grt_one_dvw_err

(Calibration failed due to more than one valid window)

rsu_multiple_valid_latencies_ err

(Calibration failed due to more than two read latencies)

If the RSU sweeps the resynchronization clock across every phase and sees multiple data valid windows, this is indicative of unexpected read data (random bit errors) or an incorrectly configured PLL which must be resolved. Calibration has failed and this output is set to 1.

If the RSU sweeps the resynchronization clock across every phase and sees valid data at more than two different latencies, then calibration fails and this output is set to 1.

Design Considerations

This section discusses the design considerations for nonAFI designs.

Clocks and Resets

The ALTMEMPHY megafunction automatically generates a PLL instance, but you must still provide the reference clock input (pll_ref_clk) with a clock of the frequency that you specified in the MegaWizard interface. An active-low global reset input is also provided, which you can de-assert asynchronously. The clock and reset management logic synchronizes this reset to the appropriate clock domains inside the ALTMEMPHY megafunction. A clock output, which is half the memory clock frequency for a half-rate controller and the same as the memory clock for a full-rate controller, is provided (phy_clk or aux_half_rate_clk) and all inputs and outputs of the ALTMEMPHY megafunction are synchronous to this clock. An active-low synchronous reset is also provided (reset_phy_clk_n). This reset_phy_clk_n signal is synchronously de-asserted with respect to the phy_clk clock domain and can reset any additional user logic on that clock domain. In addition, there is a full rate clock (aux_full_rate_clk) output available to use anywhere else in your design. This clock is derived from the mem_clk_2x PLL output signal.

Calibration Process Requirements

As the autocalibration logic makes use of the controller to perform its calibration, you should follow these guidelines at power-up. When the global reset (global_reset_n) is released, the clock management logic waits for the PLL to lock and then releases the reset to the rest of the logic, including the controller. As the PLL locked output is gated inside the PLL, for approximately the first 10,000 cycles (by this time the PLL-locked output is stable) of the PLL reference clock, there is no activity at this time. When the reset to the controller (reset_phy_clk_n) is released, the controller begins its normal memory initialization sequence. When complete, the controller indicates to the ALTMEMPHY megafunction that it is ready to accept the calibration writes and reads by asserting the ctl_init_done and ctl_ready signals in DDR3/DDR2/DDR SDRAM interfaces. (There are no such signals in QDR II+/QDR II SRAM interfaces, as the SRAM device does not need an initialization sequence other than initializing the memory DLL.) The auto-calibration logic then issues a series of writes and reads to the external memory. You do not have access to the memory controller during this period. When the autocalibration logic completes

3–42 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

its calibration, the ALTMEMPHY megafunction asserts the ctl_usr_mode_rdy, resynchronization_successful, local_init_done, and local_ready signals in DDR3/DDR2/DDR SDRAM interfaces or ctl_usr_mode_rdy and resynchronization_successful signals in QDR II+/QDR II SRAM interfaces.

You then have complete control of the memory controller.

f For more information about calibration process, refer to the Calibration section in the

DDR and DDR2 SDRAM High-Performance Controllers and ALTMEMPHY IP User Guide.

Design Considerations

Local Interface Requirements

The autocalibration logic makes use of the controller to perform its calibration, so your controller must observe the following requirements.

The controller must have at least one Avalon-MM slave interface or a native interface, which the ALTMEMPHY megafunction can control during the initial calibration process. For DDR3 SDRAM and QDR II+/QDR II SRAM variations of the ALTMEMPHY megafunction, only the Avalon-MM local interface is supported. When calibration is complete, no further access to this interface is required by the ALTMEMPHY megafunction.

The memory burst length can be two, four, or eight for DDR SDRAM devices; the memory burst length can be four or eight for DDR2 SDRAM devices; DDR3 SDRAM burst lengths can be set at either four or eight, when using the Altera highperformance controller. The QDR II+/QDR II SRAM variations of the ALTMEMPHY megafunction only support burst length of four. For a half-rate controller, the memory clock runs twice as fast as the clock provided to the local interface; so data buses on the local interface are four times as wide as the memory data bus. For a full-rate controller, the memory clock runs at the same speed as the clock provided to the local interface, so the data buses on the local interface are two times as wide as the memory data bus. Each read or write request on the local interface fits into a single memory read or write command on the memory interface, simplifying the controller design.

1 The ALTMEMPHY megafunction with the nonAFI does not support burst lengths of

eight.

DDR2/DDR SDRAM Half-Rate Controller

The following sections describe the handshake mechanism between the read commands and read data for the controller in a DDR2/DDR SDRAM interface.

f For more information about the timing diagrams of a DDR2 SDRAM

High-Performance controller, refer to the Timing Diagrams chapter in the DDR and

DDR2 SDRAM High-Performance Controllers and ALTMEMPHY IP User Guide.

1 The behavior of ctl_* signals is the same as local_* signals during calibration.

These signals switch to local_* signals after calibration.

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Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–43

phy_clk

ctl_mem_addr_h

ctl_mem_cs_h

ctl_mem_odt_h

DDR Command

(1)

mem_clk

mem_addr

mem_odt

mem_dqs

mem_dq

ctl_mem_rdata

ctl_doing_rd

ctl_mem_rdata_valid

DDR Command

(2)

mem_cs_n

2818967...

503031e...

PHY Command Input

PHY Read Data Input

PHY Command Output

Memory Interface

PHY Read Data Output

NOP NOP NOP NOPRD RDPCH ACT NOP

0000 0004 0008 000C 0010 0000

PCH NOP NOP NOP NOP ACTPCHRDACT

0000 0000 000C 000000100004 00080002

23eaf1c823eaf1c8 46c9ff8d...

8c8fe30...

0503db0...

0a06ab1...

140c4b3...

140c4b38140c4b38

Design Considerations

Handshake Mechanism Between Read Commands and Read Data

The controller generates a signal (ctl_doing_rd) to the ALTMEMPHY megafunction which is asserted for one phy_clk cycle for every read command it issues. If there are two read commands, the signal ctl_doing_rd is asserted for two

phy_clk cycles. This signal also enables the capture registers and generates the ctl_mem_rdata_valid signal. This signal should be issued at the same time the

read command is sent to the ALTMEMPHY megafunction (refer to Figure 3–12).

Figure 3–12. Read Commands and Read Data (Half-Rate Controller)

Notes to Figure 3–12:

(1) The DDR command shows the command comprised of the command signals (ctl_mem_ras_n_h, ctl_mem_cas_n_h, and

ctl_mem_we_n_h) seen at the ALTMEMPHY input. There can be more than one clock cycle of no operation (NOP) between active (ACT) to

RD depending on the value of t

parameter of your memory device.

RCD

(2) The DDR command shows the command comprised of the command signals (mem_ras_n_h, mem_cas_n_h and mem_we_n_h) seen at

the memory interface. There can be more than one clock cycle of NOP between active ACT to RD depending on the value of the t your memory device.

parameter of

RCD

1 The signals under the PHY Command Input label are the signals from the controller to

the ALTMEMPHY megafunction. The signals under the PHY Command Output label are the signals coming out of the ALTMEMPHY megafunction and input to the memory device.

3–44 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

Design Considerations

Some of the address and command signals generated by the controller are:

■ ctl_mem_addr_h

■ ctl_mem_cas_h

■ ctl_mem_cs_n_h

■ ctl_mem_ras_n_h

■ ctl_mem_we_n_h

■ ctl_mem_odt_h

Figure 3–12 shows the No Operation (NOP) command followed by a series of five

read commands.

1. The controller issues five consecutive read commands with a starting address of 0×0 with increments of four (0000, 0004, 0008, 000c, 0010), see the top of

Figure 3–12 under the PHY Command Input label.

2. The ALTMEMPHY megafunction generates the read command at the memory interface after five-to-seven memory clock (mem_clk) cycles. The address and commands are generated using the negative edge of the memory clock, see

Figure 3–12 under the PHY Command Output label.

3. The address and commands are of 2T period and the chip select is of 1T period (mem_clk).

4. The data (mem_dq) at the memory interface is presented after three memory clock cycles of read latency. The read latency is equal to the CAS latency. For this example, CAS latency is equal to three.

By default, the read data from the memory bypasses the controller and is sent directly to the user logic. If your controller requires access to the read data after it has been captured, but before it is sent to the user interface (for example, to perform error detection and correction), connect the ctl_mem_rdata and ctl_mem_rdata_valid outputs from the ALTMEMPHY megafunction to your controller. The controller must delay both ctl_mem_rdata and ctl_mem_rdata_valid signals by the same amount. Connect the read data and valid outputs of your controller to the ctl_rdata and ctl_rdata_valid inputs of the ALTMEMPHY megafunction, which passes straight through to the local_rdata and local_rdata_valid signals.

Handshake Mechanism Between Write Commands and Write Data

The controller provides a signal (ctl_mem_wdata_valid) to the ALTMEMPHY megafunction to tell it when to enable the mem_dq and mem_dqs output enables. It is the controller ’s responsibility to control the relative timing of the memory command signals (for example, mem_cas_n and mem_we_n) and the control_mem_wdata_valid or control_mem_dqs_burst signals, to meet the required memory write latency; therefore, this exact relationship is very important.

1 The ctl_mem_dqs_burst signal controls the DQS output enables of the DQS pins.

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Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–45

DDR Command

(Note 1)

phy_clk

ctl_mem_addr_h

ctl_mem_cs_n_h

ctl_mem_odt_h

mem_addr

mem_cs_n

mem_odt

mem_dq

ctl_mem_wdata_valid

ctl_mem_wdata

0000 0003 0000 0004 0008 000C 0010 0000

mem_dqs[1]

PHY Command Input

PHY Write Data Input

PHY Command Output

PHY Write Data Output

DDR Command

(Note 2)

NOP PCH NOP ACT NOP WR ACT NOP

mem_clk

ACT ACTNOP NOPWR WR

0003 0000 0004 0008 000C 0010 0000 0004 0008

cdb042d1cc72ad13

877d84bf...

13a1563...

26e92ac...

4ccf5491...

9883a83fb8e6045a

2d1b4d7...

5a369af...

Design Considerations

Figure 3–13. Write Commands and Write Data (Half-Rate Controller)

Notes to Figure 3–13:

(1) The DDR command shows the command comprised of the command signals (ctl_mem_ras_n_h, ctl_mem_cas_n_h, and

(2) The DDR command shows the command comprised of the command signals (mem_ras_n_h, mem_cas_n_h, and mem_we_n_h) seen

ctl_mem_we_n_h) seen at the ALTMEMPHY input. There can be more than one clock cycle of NOP between ACT to RD depending on the value of t

parameter of your memory device.

RCD

at the memory interface.

Figure 3–13 shows the sequence of operations that happen during the write

transactions. The write operation is explained step-by-step below. All the inputs to the ALTMEMPHY megafunction from the controller should be generated using phy_clk.

1 The signals under the PHY command input label are the signals from the controller to

the ALTMEMPHY megafunction and the signals under the PHY command output label are the signals coming out of the ALTMEMPHY megafunction and input to the memory device.

Some of the address and command signals generated by the controller are:

■ ctl_mem_addr_h

■ ctl_mem_cas_n_h

3–46 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

■ ctl_mem_cs_n_h

■ ctl_mem_ras_n_h

■ ctl_mem_we_n_h

■ ctl_mem_odt_h

Design Considerations

As can be seen in the waveform (Figure 3–13), the sequence of commands are PreCharge (PCH), ACT, and NOP, followed by a series of write commands.

1. The controller puts the five consecutive write commands with a starting address of 0 × with increments of four (0000, 0004, 0008, 000c, 0010), see the top of Figure 3–13 under the PHY Command Input label.

2. The controller generates the following signals two clock cycles after ctl_mem_wdata_valid and must supply the data ctl_mem_wdata along with these two clock cycles. Refer to Figure 3–13 under the PHY Write Data Input label.

3. The ALTMEMPHY megafunction generates the write command at the memory interface after five-to-seven memory clock (mem_clk) cycles (to accommodate the write delay). In this example, the address and commands are generated using the negative edge of the memory clock, see Figure 3–14 under the PHY Command Output label.

4. The address and commands are of 2T period and the chip select is of 1T period.

5. The data (mem_dq) at the memory interface is presented after two memory clock cycles of write latency. The write latency is equal to the CAS latency -1 for DDR2 SDRAM only (for DDR SDRAM it is always 1). For this example, CAS latency is equal to three.

6. The generation of DQS signals is controlled using the control_mem_wdata_valid signal, which is very important as the generation of the DQS signal is also dependent on the CAS latency parameter.

Figure 3–13 shows that the controller state machine asserts the

ctl_mem_wdata_valid signal to perform a write transaction. The write data (ctl_mem_wdata) should be available at the same time when the signal is asserted high. The ctl_mem_wdata_valid signal is asserted for five clock cycles (phy_clk) or ten clock cycles (mem_clk) to transfer five data transfers. The write data is only valid when the ctl_mem_wdata_valid is asserted high and is held in the wdata registers until the write occurs. In Figure 3–13, the write data bus ctl_mem_wdata is of width 64 and each burst transfer is of the length four. The 64-bit wide data is transferred to the memory as four 16-bit wide data, as shown by mem_dq. The DQS clock is twice the frequency of the clock that clocks the ctl_mem_wdata and the DQ data is transferred during both the edges of DQS.

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Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–47

Design Considerations

DDR2/DDR SDRAM Full-Rate Controller

The following section details the handshake read and handshake write function for the DDR2/DDR SDRAM full-rate controller.

f For more information about the timing diagrams of a DDR2 SDRAM

High-Performance controller, refer to the Timing Diagrams chapter in the DDR and

DDR2 SDRAM High-Performance Controllers and ALTMEMPHY IP User Guide.

Handshake Mechanism Between Read Commands and Read Data

Figure 3–14 shows the read operation for a full-rate controller. The handshake

mechanism remains similar to that of the half-rate controller except for the following differences:

1. 1T versus 2T addressing.

As the burst size is fixed at four on the memory interface, and also the address and command datapath is based on 1T addressing, it takes two memory clock cycles to retrieve the data from the memory for each read command, see Figure 3–14. The first memory cycle is the read command and the second memory cycle is the NOP command. Because of this arrangement, you see a NOP command between the read commands.

2. Assertion of the chip select signal.

The chip select signal is asserted along with the read command because of the 1T addressing.

3–48 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

Design Considerations

Figure 3–14. Read Commands and Read Data (Full-Rate Controller)

phy_clk

PHY Command Input

DDR command (

)

NOP

ctl_mem_addr_h

ctl_mem_cs_n_h

ctl_mem_odt_h

PHY Read Data Input

local_read_req

ctl_doing_rd

count_wr

local_ready

PHY Command Output

mem_clk

DDR command (

mem_cs_n

mem_addr

mem_odt

Memory Interface

mem_dq

mem_dqs

PHY Read Data Output

ctl_mem_rdata

)

0000

NOP

0000

8...

e...

000000

0...

0000

808bdae4ec55833a

0004

0008

0000

NOP

0004

0000 0008

0000 1... 0... 1... 1... 0... 1... 0... 0... 1... 0... 0... 1... 0... 1... 1... 0...

0010

000c

0000

NOP

0000 000c

1... 4... 3... 7... 0... f... 0... 0... c... 0... 1... 3... 2... 7... e... 8...

0000

0010

0000

473d 8

ctl_mem_rdata_valid

Notes to Figure 3–14:

(1) The DDR command shows the command comprised of the command signals (ctl_mem_ras_n_h, ctl_mem_cas_n_h, and

ctl_mem_we_n_h) seen at the ALTMEMPHY input. There can be more than one clock cycle of NOP between ACT to RD depending on the value

of t

parameter of your memory device.

RCD

(2) The DDR command shows the command comprised of the command signals (mem_ras_n_h, mem_cas_n_h, and mem_we_n_h) seen

at the memory interface. There can be more than one clock cycle of NOP between ACT to RD depending on the value of the t memory device.

parameter of your

RCD

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–49

Design Considerations

Handshake Mechanism Between Write Commands and Write Data

Figure 3–15 shows the write operation for the full-rate controller. The handshake

mechanism remains similar to the half-rate controller except for the following differences:

1. 1T versus 2T addressing.

As the burst size is fixed at four on the memory interface, and also the address and command datapath is based on 1T addressing, it takes two memory clock cycles to write data into the memory for each of the write commands, see Figure 3–15. The first memory cycle is the write command and the second memory cycle is the NOP command. Because of this arrangement, you see a NOP command between the write commands.

2. Assertion of the chip select signal.

The chip select signal is asserted along with the write command because of the 1T addressing.

3. To support full-rate, the controller must provide the ctl_mem_dqs_burst signal. In full-rate mode, the PHY allows separates control of the DQ and DQS output enables to support incomplete bursts. For example, if the memory burst length is four and the local side burst length is two, you may ask for a write of length one. To support this, the controller must be able to enable the DQS outputs for the full memory burst length (two clock cycles, four DQS edges) while only enabling the DQ outputs for the number of cycles that you requested (one clock cycle, two beats of data).

3–50 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

phy_clk

ctl_mem_cs_n_h

ctl_mem_addr_h

ctl_mem_odt_h

DDR Command

(1)

mem_clk

mem_addr

mem_odt

mem_dqs

mem_dq

ctl_mem_wdata_valid

DDR Command

(2)

mem_cs_n

PHY Command Input

PHY Write Data Input

PHY Command Output

NOP

local_write_req

ctl_mem_dqs_burst

NOP

0000 0008

0000

000c

0000

0010

0000

NOP

0004

0000

0000 0008

0000 000c

0000

NOP

0010

0000

000000

1... 4... 3... 7... 0... f... 0... 0... c... 0... 1... 3... 2... 7... e... 8...

000000

0000

0... 0... 1... 0... 1... 1... 0... 1... 1... 0... 1... 0... 0... 1...

0000

PHY Write Data Output

mem_dqs

ctl_mem_wdata

NOP

0004

0000

0... 0... 0... 1... 1... 1... 0... 1... 0... 1... 0... 0... 000000

808bdae4ec55833a

8e7a

1... 0... 0...

473d

02f501f4

08f304f7

20eb10fb 8e7a

40cb

808bdae4ec55833a

0... 0...

Design Considerations

Figure 3–15. Write Commands and Write Data (Full-Rate Controller)

Notes to Figure 3–15:

(1) The DDR command shows the command comprised of the command signals (ctl_mem_ras_n_h, ctl_mem_cas_n_h, and

ctl_mem_we_n_h) seen at the ALTMEMPHY input. There can be more than one clock cycle of NOP between ACT to RD depending on the value

of t

parameter of your memory device.

RCD

(2) The DDR command shows the command comprised of the command signals (mem_ras_n_h, mem_cas_n_h, and mem_we_n_h) seen at

the memory interface.

For DDR SDRAM, the write latency is fixed at one memory clock cycle, but for DDR2 SDRAM, this value changes with the read CAS latency. As the controller is running at half the rate of the memory clock, a latency change of one controller clock cycle is actually two memory clock cycles. The ALTMEMPHY megafunction allows you to dynamically insert an extra memory clock of delay in the address and command path to compensate for this. The insertion of delay is controlled by the ADDR_CMD_ADD_1T parameter and the ctl_add_1t_ac_lat signal. If ADDR_CMD_ADD_1T is set to the

Chapter 3: Functional Description—ALTMEMPHY (nonAFI) 3–51

Design Considerations

string EXT_SELECT, an extra cycle of latency can be dynamically inserted on the address and command outputs by asserting the ctl_add_1t_ac_lat input. This allows run-time control of the address and command latency. If ADDR_CMD_ADD_1T is set to the string value TRUE, the extra clock cycle of latency is always present, and if it is set to the string value FALSE, the extra latency is never added.

1 The ADDR_CMD_ADD_1T parameter value is set in <variation_name>_phy.v file and is

passed on to <project directory>\<variation_name>_alt_mem_phy.v file.

For DDR2 SDRAM interfaces using unbuffered DIMMs or components, the value of ADDR_CMD_ADD_1T should be TRUE for odd CAS latencies (CL3 or CL5) and FALSE for even CAS latencies (CL4). For registered DIMMs, the value of ADDR_CMD_ADD_1T should be FALSE for odd CAS latencies (CL3 or CL5) and TRUE for even CAS latencies (CL4), see Table 3–18.

For DDR SDRAM interfaces, the write latency is fixed at one cycle. You should use the settings for CAS latencies see Ta bl e 3 –1 8.

Tab le 3– 18 shows the setting of ADDR_CMD_ADD_1T for different values of CAS

latency and DIMM settings.

Table 3–18. ADDR_CMS_ADD_1T Settings

Memory and CL DIMM Type ADDR_CMD_ADD_1T

DDR2 SDRAM, CL3

DDR2 SDRAM, CL4

DDR2 SDRAM, CL5

DDR SDRAM

Unbuffered TRUE

Registered FALSE

Unbuffered FALSE

Registered TRUE

Unbuffered TRUE

Registered FALSE

Unbuffered FALSE

Registered TRUE

The timing of the ODT signal can be controlled in the same way but is independent of the address and command latency. If the ODT_ADD_1T parameter is set to EXT_SELECT, an extra cycle of latency can be dynamically inserted on the ODT command outputs by asserting the ctl_add_1t_odt_lat input. This allows separate run-time control of the latency of the ODT signal. If ODT_ADD_1T is set to

TRUE, the extra clock cycle of latency is always present. If ODT_ADD_1T is set to FALSE, the extra latency is never added.

3–52 Chapter 3: Functional Description—ALTMEMPHY (nonAFI)

Design Considerations

4. Support for Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices

The following sections describe the ALTMEMPHY megafunction support for Arria GX, Stratix II, and Stratix II GX devices.

1 HardCopy

However, some design considerations are specific to the HardCopy II device family.

The ALTMEMPHY megafunction does not natively support a memory interface that spans on multiple sides of the device in these device families, because the memory interface pins that are connected to the DLL are only available on the top and bottom of the device. In silicon, you can route the DLL control settings from one side of the device to another side of the device via local routing. To perform local routing, you must register the DLL control settings and to minimize the arrival skew of the DLL control settings at the other side of the device. However, this method has not been characterized and its performance is unknown. Therefore, this implementation is discouraged.

DDR2/DDR SDRAM

Arria GX, HardCopy II, Stratix II, and Stratix II GX devices support both full-rate and half-rate DDR2/DDR SDRAM PHYs.

Half-Rate Support

The following section discusses half-rate support for DDR2/DDR SDRAM for Arria GX, HardCopy II, Stratix II, and Stratix II GX devices.

II ASIC device support is similar to that of the Stratix II FPGA family.

Read Datapath

The read datapath logic is responsible for capturing data sent by the memory device and subsequently aligning the data back to the system clock domain. The following functions are performed by the read datapath:

1. Data capture and resynchronization

2. Data demultiplexing

3. Data alignment

4–2 Chapter 4: Support for Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices

SDR SDR/HDR

DDR

Data Capture IOE

Data Resynchronization

Data Demux and Alignment

rdata_1x[4n]

wr_data[2n]

rd_data[4n]

wr_clk rd_clk

FIFO

phy_clk_1x

rdata_2x_p[n]

rdata_2x_n[n]

resync_clk_2x

DQ[n]

DQS

DDR2/DDR SDRAM

Figure 4–1 shows the order of the functions performed by the read datapath, along

with the frequency at which the read data is handled.

Figure 4–1. DDR2/DDR SDRAM Read Datapath in Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices

Data Capture and Resynchronization

Data capture and resynchronization is the process of capturing the read data (DQ) with the DQS strobe and re-synchronizing the captured data to an internal free-running full-rate clock supplied by the enhanced phase-locked loop (PLL).

The resynchronization clock is an intermediate clock whose phase shift is determined during the calibration stage.

Timing constraints ensure that the data resynchronization registers are placed close to the DQ pins to achieve maximum performance. Timing constraints also further limit skew across the DQ pins. The captured data (rdata_2x_p and rdata_2x_n) is synchronized to the resynchronization clock (resync_clk_2x), see Figure 4–1.

Data Demultiplexing

Data demultiplexing is the process of SDR data into HDR data. Data demultiplexing is required to bring the frequency of the resynchronized data down to the frequency of the system clock, so that data from the external memory device can ultimately be brought into the FPGA DDR2/DDR SDRAM controller clock domain. Before data capture, the data is DDR and n-bit wide. After data capture, the data is SDR and 2n-bit wide. After data demuxing, the data is HDR of width 4n-bits wide. The system clock frequency is half the frequency of the memory clock.

Demultiplexing is achieved using a dual-port memory with a 2n-bit wide write-port operating on the resynchronization clock (SDR) and a 4n-bit wide read-port operating on the PHY clock (HDR). The basic principle of operation is that data is written to the memory at the SDR rate and read from the memory at the HDR rate while incrementing the read- and write-address pointers. As the SDR and HDR clocks are generated, the read and write pointers are continuously incremented by the same PLL, and the 4n-bit wide read data follows the 2n-bit wide write data with a constant latency.

Chapter 4: Support for Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices 4–3

resync_clk_2x

postamble_clk

dqs (90˚ shifted)

Data input to resync reg's

ARST at postamble reg's

H1L1

H2L2

DDR2/DDR SDRAM

Read Data Alignment

Data alignment is the process controlled by the sequencer to ensure the correct captured read data is present in the same half-rate clock cycle at the output of the read data DPRAM. Data alignment is implemented using either M4K or M512K memory blocks. The bottom of Figure 4–2 shows the concatenation of the read data into valid HDR data.

Postamble Protection

The ALTMEMPHY megafunction provides the DQS postamble logic. The postamble clock is derived from the resynchronization clock and is the negative edge of the resynchronization clock. The ALTMEMPHY megafunction calibrates the resynchronization clock such that it is in the center of the data-valid window. The clock that controls the postamble logic, the postamble clock, is the negative edge of the resynchronization clock. No additional clocks are required. Figure 4–2 shows the relationship between the postamble clock and the resynchronization clock.

Figure 4–2. Relationship Between Postamble Clock and Resynchronization Clock (Note 1)

Note to Figure 4–2:

(1) resync_clk_2x is delayed further to allow for the I/O element (IOE) to core transition time.

f For more information about the postamble circuitry, refer to the External Memory

Interfaces chapter in the Stratix II Device Handbook.

Clock and Reset Management

The clocking and reset block is responsible for clock generation, reset management, and phase shifting of clocks. It also has control of clock network types that route the clocks.

4–4 Chapter 4: Support for Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices

DDR2/DDR SDRAM

Clock Management

The ability of the ALTMEMPHY megafunction to work out the optimum resynchronization clock phase during calibration, and to track the system voltage and temperature (VT) variations. Clock management is done by phase-shifting the clocks relative to each other.

Clock management circuitry is implemented by using the following device resources:

■ PLL

■ PLL reconfiguration

■ DLL

PLL

The ALTMEMPHY MegaWizard interface automatically generates an ALTPLL megafunction instance. The ALTPLL megafunction is responsible for generating the different clock frequencies and relevant phases used within the ALTMEMPHY megafunction.

The minimum PHY requirement is to have 16 phases of the highest frequency clock. The PLL uses With no compensation operation mode to minimize jitter.

You must choose a PLL and PLL input clock pin that are located on the same side of the memory interface to ensure minimal jitter. Cascaded PLLs are not recommended for DDR2/DDR SDRAM interfaces as jitter can accumulate with the use of cascaded PLLs causing the memory output clock to violate the memory device jitter specification. Also, ensure that the input clock to the PLL is stable before the PLL locks. If not, you must perform a manual PLL reset and relock the PLL to ensure that the phase relationship between all PLL outputs are properly set.

1 If the design cascades PLLs, the source (upstream) PLL should have a low-bandwidth

setting; the destination (downstream) PLL should have a high-bandwidth setting. Adjacent PLLs cascading is recommended to reduce clock jitters.

f For more information about the VCO frequency range and the available phase shifts,

refer to the PLLs in Stratix II and Stratix II GX Devices chapter in the respective device family handbook.

Chapter 4: Support for Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices 4–5

DDR2/DDR SDRAM

Tab le 4– 1 shows the clock outputs that Arria GX, HardCopy II, Stratix II and

Stratix II GX devices use.

Table 4–1. DDR2/DDR SDRAM Clocking in Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices (Part 1 of 2)

Design

Rate Clock Name

Half-rate phy_clk_1x

and

aux_half_rate_ clk

mem_clk_2x

and

aux_full_ rate_clk

Full rate aux_half_rate_

clk

phy_clk_1x (1)

and

mem_clk_2x

Postscale

Counter

Phase

(Degrees) Clock Rate

Clock

Network Type Notes

C0 0 Half-Rate Global The only clock that is

made available on the user interface of the ALTMEMPHY megafunction. This clock also feeds into a divider circuit to provide the PLL scan_clk signal (for reconfiguration) that must be lower than 100 MHz.

C1 0 Full-Rate Global This clock is for clocking

DQS and as a reference clock for the memory devices.

C0 0 Half-Rate Global The only clock that is

C1 0 Full-Rate Global This clock is for clocking

DQS and as a reference clock for the memory devices.

and

aux_full_ rate_clk

Half-rate and full rate

write_clk_2x C2 –90 Full-Rate Global This clock is for clocking

the data out of the DDR I/O (DDIO) pins in advance of the DQS strobe (or equivalent). As a result, its phase leads that of the mem_clk_2x by 90°.

4–6 Chapter 4: Support for Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices

DDR2/DDR SDRAM

Table 4–1. DDR2/DDR SDRAM Clocking in Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices (Part 2 of 2)

Design

Rate Clock Name

Half-rate

mem_clk_ext_2x C3 > 0 Full-Rate Dedicated This clock is only used if

Postscale

Counter

Phase

(Degrees) Clock Rate

and full rate

Half-rate

resync_clk_2x C4 Calibrated Full-Rate Regional Clocks the

and full rate

Half-rate

measure_clk_2x C5 Calibrated Full-Rate Regional (2) This clock is for VT

and full rate

Half-rate and full rate

ac_clk_2x —0,

Full-Rate Global The ac_clk_2x clock is

90,180,

270

Notes to Table 4–1:

(1) In full-rate designs a _1x clock may run at full-rate clock rate. (2) This clock should be of the same clock network clock as the resync_clk_2x clock.

Clock

Network Type Notes

the memory clock generation uses dedicated output pins. Applicable only in HardCopy II or Stratix II prototyping for HardCopy II designs.

resynchronization registers after the capture registers. Its phase is adjusted to the center of the data valid window across all the DQS-clocked DDIO groups.

tracking. This free-running clock measures relative phase shifts between the internal clock(s) and those being fed back through a mimic path. As a result, the ALTMEMPHY megafunction can track VT effects on the FPGA and compensate for the effects.

derived from either mem_clk_2x (when you choose 0 or 180 phase shift) or write_clk_2x (when you choose 90 or 270 phase shift).

PLL Reconfiguration

The ALTMEMPHY MegaWizard interface automatically generates the PLL reconfiguration block by instantiating an ALTPLL_RECONFIG variation for Stratix II and Stratix II GX devices to match the generated ALTPLL megafunction instance. The ALTPLL_RECONFIG megafunction varies the resynchronization clock phase and the measure clock phase.

Chapter 4: Support for Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices 4–7

DDR2/DDR SDRAM

DLL

A DLL instance is included in the generated ALTMEMPHY variation. When using the DQS to capture the DQ read data, the DLL center-aligns the DQS strobe to the DQ data. The DLL settings depend on the interface clock frequency.

f For more information, refer to the External Memory Interfaces chapter in the device

handbook for your target device family.

Reset Management

The reset management block is responsible for the following:

■ Provides appropriately timed resets to the ALTMEMPHY megafunction datapaths

and functional modules

■ Performs the reset sequencing required for different clock domains

■ Provides reset management of PLL and PLL reconfiguration functions

■ Manages any circuit-specific reset sequencing

Each reset is an asynchronous assert and synchronous de-assert on the appropriate clock domain. The reset management design uses a standard two-register synchronizer to avoid metastability. A unique reset metastability protection circuit for the clock divider circuit is required because the phy_clk domain reset metastability protection flipflops have fan-in from the soft_reset_n input, and so these registers cannot be used.

Figure 4–3 shows the ALTMEMPHY reset management block for Arria GX,

HardCopy II, Stratix II, and Stratix II GX devices. The pll_ref_clk signal goes directly to the PLL, eliminating the need for global clock network routing. If you are using the pll_ref_clk signal to feed other parts of your design, you must use a global clock network for the signal. If pll_reconfig_soft_reset_en is held low, the PLL reconfig is not reset during a soft reset, which allows designs targeting HardCopy II devices to hold the PHY in reset while still accessing the PLL reconfig block. However, designs targeting Arria GX or Stratix II devices are expected to tie the pll_reconfig_soft_en shell to VCC to enable PLL reconfig soft resets.

PLL

SET

CLR

SET

CLR

SET

CLR

SET

CLR

SET

CLR

PLL

reconfig

SET

CLR

soft_reset_n

global_reset_n

pll_ref_clk

phy_clk_out

reset_request_n

phy_internal_reset_n

areset (active HIGH)

pll_reconfig_reset_ams_n

pll_reconfig_reset_ams_n_r

refclk

locked

reset_master_ams

scan_c l k

reset

global_pre_clear

Reset pipes

PHY r esets

pll_reset

pll_locked

Optional

reset_

request_n

edge detect and

reset counter

Another system clock

clk_divider_reset_n

clk

divider

circuit

phy_clk

reset_n

scan_clk

clk_div_reset_ams_n

clk_div_reset_ams_n_r

pll_reconfig_soft_reset_en

pll_reconfig_reset_n

global_or_soft_reset_n

4–8 Chapter 4: Support for Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices

Figure 4–3. ALTMEMPHY Reset Management Block for Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices

Write Datapath

The write datapath logic efficiently transfers data from the HDR memory controller to DDR SDRAM-based memories. The write datapath logic consists of:

■ DQ and DQ output-enable logic

■ DQS and DQS output-enable logic

■ Data mask (DM) logic

DDR2/DDR SDRAM

Chapter 4: Support for Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices 4–9

Write Datapath

Stratix II IOE

wdp_wdata_l

phy_clk_1x (ctl_clk)

DQ[n]

write_clk_2x

ctl_wdata[4n]

write_clk_2x

Data

Multiplexing

wdp_wdata_h

DDR2/DDR SDRAM

The memory controller interface outputs 4n-bit wide data (ctl_wdata[4n]) at halfrate frequency. Figure 4–4 shows that the HDR write data (ctl_wdata[4n]) is clocked by the half-rate clock phy_clk_1x and is converted into SDR which is represented by wdp_wdata_h and wdp_wdata_l and clocked by the full-rate clock write_clk_2x.

The DQ IOEs convert 2-n SDR bits to n-DDR bits.

Figure 4–4. DDR2/DDR SDRAM Write Datapath in Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices

Address and Command Datapath

The address and command datapath is responsible for taking the address and command outputs from the controller and converting them from half-rate clock to full-rate clock. Two types of addressing are possible:

■ 1T (full rate)—The duration of the address and command is a single memory clock

cycle (mem_clk_2x, Figure 4–5). This applies to all address and command signals in full-rate designs or mem_cs_n, mem_cke, and mem_odt signals in half-rate designs.

■ 2T (half rate)—The duration of the address and command is two memory clock

cycles. For half-rate designs, the ALTMEMPHY megafunction supports only a burst size of four, which means the burst size on the local interface is always set to

1. The size of the data is 4n-bits wide on the local side and is n-bits wide on the memory side. To transfer all the 4n-bits at the double data rate, two memory-clock cycles are required. The new address and command can be issued to memory every two clock cycles. This scheme applies to all address and command signals, except for mem_cs_n, mem_cke, and mem_odt signals in half-rate mode.

f Refer to Table 4–1 in “PLL” on page 4–4 to see the frequency relationship of

mem_clk_2x with the rest of the clocks.

Figure 4–5 shows a 1T chip select signal (mem_cs_n), which is active low, and

disables the command in the memory device. All commands are masked when the chip-select signal is inactive. The mem_cs_n signal is considered part of the command code.

4–10 Chapter 4: Support for Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices

Command

ac_clk_2x

mem_addr

mem_ba

mem_cs_n

mem_ras_n

mem_cas_n

mem_we_n

mem_dq

NOP

mem-dqs

PHY Command Outputs

NOP

PCH ACT

0000

0001

0000

0004

0008

000C

0010 0000

DDR2/DDR SDRAM

Figure 4–5. Arria GX, HardCopy II, Stratix II, and Stratix II GX Address and Command Datapath

The command interface is made up of the signals mem_ras_n, mem_cas_n, mem_we_n, mem_cs_n, mem_cke, and mem_odt.

The waveform in Figure 4–5 shows a NOP command followed by five back-to-back write commands.

1. The commands are asserted either on the rising edge of ac_clk_2x. The ac_clk_2x is derived from either mem_clk_2x (0 the inverted variations of those two clocks (for 180

), write_clk_2x (270), or

 and 90 phase shifts). This

depends on the setting of the address and command clock in the ALTMEMPHY MegaWizard interface.

2. All address and command signals (except for mem_cs_ns, mem_cke, and mem_odt signals) remain asserted on the bus for two clock cycles, allowing sufficient time for the signals to settle.

3. The mem_cs_n, mem_cke, and mem_odt signals are asserted during the second cycle of the address/command phase.

4. By asserting the chip-select signal in alternative cycles, back-to-back read or write commands can be issued.

5. The address is incremented every other ac_clk_2x cycle.

1 The ac_clk_2x clock is derived from either mem_clk_2x (when you choose 0° or

180° phase shift) or write_clk_2x (when you choose 90° or 270° phase shift).

1 The address and command clock can be 0, 90, 180, or 270° from the system clock.

Chapter 4: Support for Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices 4–11

DDR2/DDR SDRAM

Full-Rate Support

The following section discusses full-rate support for Arria GX, HardCopy II, Stratix II, and Stratix II GX devices.

Read Datapath

The full-rate datapath is similar to the half-rate datapath. The full-rate datapath also consists of a RAM with the same width as the data input (just like that of the half-rate), but the width on the data output of the RAM is half that of the half-rate PHY. The function of the RAM is to transfer the read data from the resynchronization clock domain to the system clock domain.

Postamble Protection

The postamble protection is the same as the half-rate support.

Clock and Reset Management

For full-rate clock and reset management refer to. The PLL is configured exactly in the same way as in half-rate designs. The PLL information and restriction from half-rate designs also applies.

1 The phy_clk_1x clock is now full-rate, despite the “1x” naming convention.

Write Datapath

The write datapath is similar to the half-rate PHY. The IOE block is identical to the half-rate PHY. The latency of the write datapath in the full-rate PHY is less than in the half-rate PHY because the full-rate PHY does not have the half-rate-to-full-rate conversion logic.

Address and Command Datapath

The address and command datapath for full-rate designs is similar to half-rate designs, except that the address and command signals are all asserted for one memory clock cycle only (1T signaling).

4–12 Chapter 4: Support for Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices

DDR2/DDR SDRAM

Additional Information

Revision History

The table below displays the revision history for the chapters in this user guide.

Date and

Document

Version Changes Made Summary of Changes

January 2010, v9.1 SP1

June 2009, v7.2

April 2009, v7.1

March 2009, v7.0

November 2008, v6.0

July 2008, v5.0

■ Removed AFI information and added AFI information references to

the External Memory Interface Handbook

■ Moved the nonAFI information to Chapter 3, Functional

Description—ALTMEMPHY (nonAFI)

■ Added support for DDR3 SDRAM unbuffered DIMM multirank

memory configurations on Stratix III and Stratix IV devices

■ Added DDR3 SDRAM without leveling

■ Added new signals:

aux_scan_clk_reset_n PLL reconfiguration signals

■ Included Arria II GX information

■ Updated generated files list

■ Updated AFI information

■ Moved nonAFI information to appendix

■ Added AFI timing diagrams for reads

■ Updated calibration process to indicate multiple chip select

calibration is supported by all devices

■ Added “DDR3 SDRAM (Discrete Device) and DDR2/DDR SDRAM

Calibration” section

■ Added clock sharing information

■ Changed pin_assignments.tcl description

■ Added section on dynamic OCT support

■ Included HardCopy IV information

■ Added Altera PHY interface (AFI) information

■ Amended HDL source file names to remove <device name>

■ Added ×36 emulation information

■ Included HardCopy III and Stratix IV information

■ Updated to include changes in the Quartus II software version 8.0

■ Moved Appendix A to the end of Chapter 1

■ Updated all sections in Chapters 1, 2, and 3

■ Added Chapters 4, 5, 6, and 7

—

Info–2 Chapter : Additional Information

Date and

Document

Version Changes Made Summary of Changes

December 2007 v4.1

December 2007 v4.0

June 2007 v3.0

March 2007 v2.0

February 2007 v1.0

Updated Figure A–4. —

Updated to include changes in the Quartus II software version 7.2. —

Updated to include Arria GX and changes included in the Quartus II software version 7.1.

Updated to included Cyclone III information. —

Initial release. —

How to Contact Altera

—

How to Contact Altera

For the most up-to-date information about Altera products, see the following table.

Contact

Contact (Note 1)

Technical support Website www.altera.com/support

Technical training Website www.altera.com/training

Altera literature services Email literature@altera.com

Non-technical support (General) Email nacomp@altera.com

(Software Licensing) Email authorization@altera.com

Note:

(1) You can also contact your local Altera sales office or sales representative.

Method Address

Email custrain@altera.com

Typographic Conventions

The following table shows the typographic conventions that this document uses.

Visual Cue Meaning

Bold Type with Initial Capital Letters

bold type Indicates directory names, project names, disk drive names, file names, file name

Italic Type with Initial Capital Letters Indicates document titles. For example, AN 519: Stratix IV Design Guidelines.

Italic type Indicates variables. For example, n + 1.

Indicates command names, dialog box titles, dialog box options, and other GUI labels. For example, Save As dialog box. For GUI elements, capitalization matches the GUI.

extensions, dialog box options, software utility names, and other GUI labels. For example, \qdesigns directory, d: drive, and chiptrip.gdf file.

Variable names are enclosed in angle brackets (< >). For example, <file name> and <project name>.pof file.

Chapter : Additional Information Info–3

Typographic Conventions

Visual Cue Meaning

Initial Capital Letters Indicates keyboard keys and menu names. For example, Delete key and the Options

menu.

“Subheading Title” Quotation marks indicate references to sections within a document and titles of

Quartus II Help topics. For example, “Typographic Conventions.”

Courier type Indicates signal, port, register, bit, block, and primitive names. For example, data1,

tdi, and input. Active-low signals are denoted by suffix n. For example, resetn.

Indicates command line commands and anything that must be typed exactly as it appears. For example, c:\qdesigns\tutorial\chiptrip.gdf.

Also indicates sections of an actual file, such as a Report File, references to parts of files (for example, the AHDL keyword SUBDESIGN), and logic function names (for example, TRI).

1., 2., 3., and a., b., c., and so on.

■ ■ Bullets indicate a list of items when the sequence of the items is not important.

Numbered steps indicate a list of items when the sequence of the items is important, such as the steps listed in a procedure.

1 The hand points to information that requires special attention. c

A caution calls attention to a condition or possible situation that can damage or destroy the product or your work.

A warning calls attention to a condition or possible situation that can cause you injury.

r The angled arrow instructs you to press Enter. f The feet direct you to more information about a particular topic.

Altera External Memory PHY Interface User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Contents

1. About this Megafunction

2. Parameter Settings

Memory Settings

Creating an Emulated x36 QDR II+/QDR II SRAM ALTMEMPHY Variation

QDR II+/QDR II SRAM Calibration Process

PHY-to-Controller Interfaces

Initialization Timing

ALTMEMPHY Signals

DDR2 and DDR SDRAM Signals

QDR II+/QDR II SRAM Signals

Understanding the Testbench

PLL Initialization and Lock

Memory Device Initialization

Interface Training and Calibration

Functional Memory Use

Functional Simulation—the ModelSim Wave and Transcript Window

Full Window Stage Identification

Initialization Stage

Write Training Data Stage

Read Calibration Phase

Functional Memory Use Stage

Additional Debug Signals

PLL and PLL Reconfiguration Signals

Calibration Status Interface

Additional Calibration Status Interface Signals

Design Considerations

Clocks and Resets

Calibration Process Requirements

Local Interface Requirements

DDR2/DDR SDRAM Half-Rate Controller

DDR2/DDR SDRAM Full-Rate Controller

4. Support for Arria GX, HardCopy II, Stratix II, and Stratix II GX Devices

DDR2/DDR SDRAM

Half-Rate Support

Full-Rate Support

Additional Information

Revision History

How to Contact Altera

Typographic Conventions