Please note that in this databook, references to "DVI" and "HDMI" may refer to: (1) the function of the integrated DVI/HDMI interface described in details in section
2.3 and 3.8, as well as in other sections; or (2) the capability of the TMDS interface, multiplexed on the PCI-E external graphics interface, to enable DVI or HDMI
through passive enabling circuitries. Any statement in this databook on any DVI or HDMI-related functionality must be understood to apply to (1), (2), or both, according
to the immediate context of the reference.
USE OF THIS PRODUCT IN ANY MANNER THAT COMPLIES WITH THE MPEG-2 STANDARD IS EXPRESSLY PROHIBITED WITHOUT A LICENSE
UNDER APPLICABLE PATENTS IN THE MPEG-2 PATENT PORTFOLIO, WHICH LICENSE IS AVAILABLE FROM MPEG LA, L.L.C., 6312 S. FIDDLERS
GREEN CIRCLE, SUITE 400E, GREENWOOD VILLAGE, COLORADO 80111.
Trademarks
AMD, the AMD Arrow, ATI, the ATI logo, 3Dc+, AMD Athlon, AMD Phenom, AMD OverDrive, AMD PowerNow!, Avivo, Cool’n’Quiet, HyperMemory, PowerPlay,
PowerShift, AMD PowerXpress, AMD Radeon, SurroundView, Vari-Bright, CrossFire, and combinati ons thereof are trademarks of Advanced Micro Devices, Inc.
DisplayPort is a trademark of the Video Electronics Standards Assoctation.
HyperTransport is a trademark of the HyperTransport Technology Consortium.
Microsoft, Windows, Windows Vista, Windows 7, DirectDraw, and DirectX are registered trademarks of Microsoft Corporation.
OpenGL is a registered trademark of Silicon Graphics Internal.
PCI Express and PCIe are registered trademarks of PCI-SIG.
WinBench is a registered trademark of Ziff Davis, Inc.
Linux is a registered trademark of Linus Torvalds in the U.S. and other countries.
Other product names used in this publication are for identification purposes only and may be trademarks of their respective companies.
Disclaimer
The contents of this document are provided in connection with Advanced Micro Devices, Inc. ("AMD") products. AMD makes no representations or warranties with
respect to the accuracy or completeness of the contents of this publication and reserves the right to make changes to specifications and product descriptions at any time
without notice. No license, whether express, implied, arising by estoppel, or otherwise, to any intellectual property rights are granted by this publication. Except as set
forth in AMD's Standard Terms and Conditions of Sale, AMD assumes no liability whatsoever, and disclaims any express or implied warranty, relating to its products
including, but not limited to, the implied warranty of merchantability, fitness for a particular purpose, or infringement of any intellectual property right.
AMD's products are not designed, intended, authorized or warranted for use as components in systems intended for surgical implant into the body, or in other applications
intended to support or sustain life, or in any other application in which the failure of AMD's product could create a situation where personal injury, death, or severe
property or environmental damage may occur. AMD reserves the right to discontinue or make changes to its products at any time without notice.
1.1 Introducing the RS880 ........................................................................................................................................................1-1
1.2 RS880 Features ...................................................................................................................................................................1-2
1.2.5A-Link Express II Interface..................................................................................................................................1-3
1.2.8Motion Video Acceleration Features....................................................................................................................1-5
1.2.9Multiple Display Features ....................................................................................................................................1-5
1.2.12Integrated HD Audio Controller and Codec.........................................................................................................1-8
1.2.14Power Management Features ...............................................................................................................................1-8
1.5 Graphics Device ID and Graphics Engine Clock Speed...................................................................................................1-10
1.6 Conventions and Notations ...............................................................................................................................................1-10
1.6.6Acronyms and Abbreviations.............................................................................................................................1-11
2.3.1DVI/HDMI™ Data Transmission Order and Signal Mapping ............................................................................2-6
2.3.2Support for HDMI™ Packet Types......................................................................................................................2-9
3.1 Pin Assignment Top View..................................................................................................................................................3-2
3.1.1RS880 Pin Assignment Top View........................................................................................................................3-2
3.3 CPU HyperTransport™ Interface .......................................................................................................................................3-5
3.5.11 x 16 Lane Interface for External Graphics ....................................................................................................... 3-6
3.5.2A-Link Express II Interface for Southbridge....................................................................................................... 3-6
3.5.36 x 1 Lane Interface for General Purpose External Devices .............................................................................. 3-6
3.11 Power Management Pins................................................................................................................................................3-11
3.13 Power Pins...................................................................................................................................................................... 3-12
5.1.1Maximum and Minimum Ratings........................................................................................................................ 5-1
5.3 Package Information .......................................................................................................................................................... 5-8
5.3.3Board Solder Reflow Process Recommendations ............................................................................................. 5-10
Chapter 6: Power Management and ACPI
6.1 ACPI Power Management Implementation ....................................................................................................................... 6-1
6.2 Power Management for the Graphics Controller ............................................................................................................... 6-2
6.2.1PCI Function Power States.................................................................................................................................. 6-2
6.2.2PCI Power Management Interface....................................................................................................................... 6-2
6.2.3Capabilities List Data Structure in PCI Configuration Space ............................................................................. 6-2
7.1 Test Capability Features......................................................................................................................................................7-1
7.2 Test Interface.......................................................................................................................................................................7-1
7.3 XOR Test ............................................................................................................................................................................7-1
7.3.1Description of a Generic XOR Tree.....................................................................................................................7-1
7.3.2Description of the RS880 XOR Tree....................................................................................................................7-2
7.3.3XOR Tree Activation ...........................................................................................................................................7-2
7.3.4XOR Tree for the RS880......................................................................................................................................7-2
7.4.1Description of a Generic VOH/VOL Tree ...........................................................................................................7-4
7.4.2VOH/VOL Tree Activation..................................................................................................................................7-5
A.1 RS880 Pin List Sorted by Ball Reference..........................................................................................................................1-2
A.2 RS880 Pin List Sorted by Pin Name..................................................................................................................................1-7
Figure 1-1: Possible Configurations for the x16 PCIe® Graphics Interface ................................................................................. 1-3
Figure 6-1: Linked List for Capabilities ......................................................................................................................................... 6-5
Figure 7-1: Example of a Generic XOR Tree ................................................................................................................................7-2
Figure 7-2: Sample of a Generic VOH/VOL Tree ......................................................................................................................... 7-5
Table 1-1: Possible Configurations for the PCIe® General Purpose Links ....................................................................................1-3
Table 1-2: Graphics Device ID and Graphics Engine Clock Speed .............................................................................................1-10
Table 1-3: Pin Type Codes ............................................................................................................................................................1-10
Table 1-4: Acronyms and Abbreviations ......................................................................................................................................1-11
Table 2-4: DDR3 Memory Row and Column Addressing ..............................................................................................................2-5
Table 2-5: Single Link Signal Mapping for DVI/HDMI™ ...........................................................................................................2-7
Table 2-6: Dual-Link Signal Mapping for DVI ..............................................................................................................................2-8
Table 2-7: Support for HDMI™ Packet Type .................................................................................................................................2-9
Table 3-3: 1 x 16 Lane PCI Express® Interface for External Graphics ..........................................................................................3-6
Table 3-4: 1 x 4 Lane A-Link Express II Interface for Southbridge ...............................................................................................3-6
Table 3-5: 6 x 1 Lane PCI Express® Interface for General Purpose External Devices ..................................................................3-6
Table 3-18: Power Pins .................................................................................................................................................................3-12
Table 3-20: Strap Definitions for the RS880 ................................................................................................................................3-14
Table 4-1: Timing Requirements for HyperTransport™ Reference Clock (100MHz) Output by the Clock Generator ................4-1
Table 4-3: Timing Requirements for REF_CLKP Used as OSCIN (14.3181818MHz) .................................................................4-2
Table 4-4: RS880 Power Rail Power-up Sequence .........................................................................................................................4-3
Table 5-1: Maximum and Minimum Ratings .................................................................................................................................. 5-1
Table 5-2: DC Characteristics for 3.3V TTL Signals .....................................................................................................................5-2
Table 5-3: DC Characteristics for DDC Signals (DDC Mode) .......................................................................................................5-2
Table 5-4: DC Characteristics for AUX Signals (AUX Mode) ......................................................................................................5-2
Table 5-5: DC Characteristics for POWERGOOD .........................................................................................................................5-2
Table 5-6: DC Characteristics for HyperTransport™ and PCI-E Differential Clock (HT_REFCLK, GFX_REFCLK,
Table 5-7: DC Characteristics for REFCLK_P as OSCIN Input (14.3181818MHz) .....................................................................5-3
Table 5-8: DC Characteristics for the Memory Interface when Supporting DDR2 ........................................................................5-3
Table 5-9: DC Characteristics for the Memory Interface when Supporting DDR3 ........................................................................5-3
Table 5-10: DC Characteristics for the Integrated DVI/HDMI™ ..................................................................................................5-4
Table 5-11: DC Characteristics for the TMDS Interface Multiplexed on the PCI Express® Gfx Lanes ......................................5-4
Table 5-12: Electrical Specifications for the DisplayPort Interface ..............................................................................................5-5
Table 6-1: ACPI States Supported by the RS880 ............................................................................................................................6-1
Table 6-2: ACPI Signal Definitions ................................................................................................................................................6-1
Table 6-3: Standard PCI Configuration Space Header Type 0 .......................................................................................................6-2
Table 6-4: PCI Status Register ........................................................................................................................................................6-3
Table 6-9: Next Item Pointer (NEXT_ITEM_PTR) .......................................................................................................................6-5
Table 6-10: Power Management Capabilities – PMC .....................................................................................................................6-6
Table 7-1: Pins on the Test Interface ..............................................................................................................................................7-1
Table 7-2: Example of an XOR Tree ..............................................................................................................................................7-2
Table 7-3: RS880 XOR Tree ...........................................................................................................................................................7-3
Table 7-4: Truth Table for the VOH/VOL Tree Outputs ................................................................................................................7-5
Table 7-5: RS880 VOH/VOL Tree .................................................................................................................................................7-7
The RS880 is a ninth-generation Integrated Graphics Processor (IGP) that integrates a DirectX® 10.1 compliant Shader
Model 4.1 graphics core and a system controller in a single chip. It supports AMD’s AM3-socket CPUs, including the
AMD Phenom™ II and later desktop processors. The RS880 integrates an ATI RV620-based graphics engine, dual
display, an integrated DVI/HDMI™ interface, a TMDS interface, DisplayPort capability, and Northbridge functionality in
a single BGA package. This high level of integration and scalability enables manufacturers to offer enthusiast level
capabilities and performance while helping to minimize board space and system cost.
The RS880 is pin-compatible with AMD's mainstream 700 and 800-series products including the RS780, RS780M,
RX780, RX781, RS880M, and RX881, allowing a single design to target multiple market seg ment s .
Robust and Flexible Core Logic Features
The RS880 combines graphics and system logic functions in a single chip using a 21mm body BGA package, reducing
overall solution area. For optimal system and graphics performance, the RS880 supports a high speed HyperTransport™
interface to the AMD processor, running at a data rate of up to 4.4 GT/s and supporting both HT 1.0 and HT 3.0 protocols.
The RS880 is ideally suited for 64-bit operating systems, and supports platform configurations with greater than 4GB of
system memory. The rich PCI Express
external graphics and up to six other PCI Express peripherals, all supporting the PCI Express 2.0 standard with data rates
of up to 5.0GT/s. These capabilities are complemented by the advanced I/O features of AMD’s SB700-series
Southbridges.
Designed for Windows Vista
Chapter 1
Overview
®
(PCIe®) expansion capabilities of RS880 include support for PCI Express
®
The RS880 delivers a compelling Windows Vista experience. It harnesses the increased bandwidth of HyperTransport 3.0
to a DirectX 10.1 graphics core, which provides the 3D rendering power needed to generate the Windows Vista desktop
even under the most demanding circumstances. The AMD RV620-based graphics core employs a unified shader
architecture to deliver excellent 3D performance across the whole spectrum of 3D applications. It meets all current
Windows Vista Premium Logo requirements.
Leading Multimedia Capabilities
The RS880 incorporates AMD’s Unified Video Decoder (UVD) 2.0 technology, which provides dedicated hardware
decode of the H.264, VC-1, and MPEG-2 video formats used for HD contents and Blu-ray disks. The RS880 also
incorporates the innovative AMD Avivo™ HD display architecture, providing users with amazing visual quality.
Advanced scaling and color correction capabilities, along with increased precision through the entire display pipeline,
ensure an exceptional image on CRT monitors, LCD panels, and any other display device. Dual DisplayPort output
capability provides the ability to interface to the next generation of digital display devices. That is complemented by a
fully integrated DVI/HDMI and HDCP support, allowing compatibility with even the most modern high definition
televisions without the additional cost of external components.
*Note: AMD Avivo HD is a technology platform that includes a broad set of capabilities offered by certain AMD
Radeon™ products. Support for any AMD Avivo HD capability is subject to qualification of the RS880 ASIC. Full
enablement of some AMD Avivo HD capabilities may require complementary products.
Low Power Consumption and Industry Leading Power Manage ment
The RS880 is manufactured using the power efficient 55 nm technology, and it supports a whole range of industry
standards and new proprietary power management features. System power can be further reduced through the dedicated
local frame buffer interface supported by the RS880. The integrated UVD dramatically reduces CPU loading and hence
overall power consumption during Blu-ray video and HD contents playback.
The graphics driver for the RS880 is fully compatible with all other AMD Radeon™ class graphics controllers from
AMD. A single driver can support multiple graphics configurations across AMD’s product lines, including the AMD
Radeon family and the AMD chipset family. In addition, this driver compatibilit y allows the RS880 to benefit
immediately from AMD's software optimization and from the advanced Windows
Windows 7
®
support available in the Radeon family drivers.
1.2RS880 Features
1.2.1 CPU HyperTransport™ Interface
•
Supports 16-bit up/down HyperTransport (HT) 3.0 interface up to 4.4 GT/s.
•Supports 200, 400, 600, 800, and 1000 MHz HT1 frequencies.
•Supports 1.6, 1.8, 2.0, and 2.2 GHz HT3 frequencies.
•Supports AMD’s AM3-socket CPUs, including the AMD Phenom II and later desktop processors.
•Supports LDTSTOP interface and CPU link stutter mode.
1.2.2 Memory Interface
Supports an optional dedicated local frame buffer (side-port) of up to 128MB through a 16-bit interface. Note,
•
however, that the memory interface is optimized for a 64MB local frame buffer. As such, the system BIOS will
downsize the side-port size if a 128MB memory device is populated.
•New highly flexible memory architecture allows asymmetric side-port and shared system memory frame buffer sizes.
Supported configurations include UMA only and UMA+side-port (interleave mode).
•New dynamic memory allocation scheme improves performance and reduces power simultaneously.
•Support for DDR2 system memories up to DDR2-800, with a maximum memory clock speed of 400MHz. Memory
clock is independent of any other clock source and can therefore be set to any frequency equal to or less than
400MHz (DDR2-800), allowing the use of lower speed side-port memories.
•Support for DDR3 system memories up to DDR3-1200, with a maximum memory clock speed of 600MHz. Memory
clock is independent of any other clock source and can therefore be set to any frequency equal to or less than
600MHz (DDR3-1200), allowing the use of lower speed side-port memories.
•Support one memory device of x16 width (see section 2.2.1.1, “Supported DDR2 Components,” on page 2-4.and
section 2.2.2.1, “Supported DDR3 Components,” on page 2-5, for details).
•Asynchronous HyperTransport and memory controller interface speeds.
•Supports DDR SDRAM self refresh mechanism.
•Supports dynamic CKE and ODT for power conservation.
RS880 Features
®
XP, Windows Vista®, and
1.2.3 AMD HyperMemory™
•Supports AMD HyperMemory™*.
* Note: Includes dedicated and shared memory. The amount of HyperMemory available is determined by various factors.
For details, please consult your AMD CSS representative.
1.2.4 PCI Express® Interface
•
Supports PCIe Gen2 (version 2.0).
•Optimized peer-to-peer and general purpose link performance.
•Highly flexible PCI Express implementation to suit a variety of platform needs.
•A dual-port, x16 graphics interface, configurable to any one of the modes illustrated in Figure 1-1for the RS880:
•Supports a maximum resolution of 2560x1600 @60Hz with 4 lanes.
1.2.12 Integrated HD Audio Controller and Codec
•
Integrated HD Audio codec supports linear PCM and AC3 (5.1) audio formats for HDMI output.
•Separate logical chip function.
•Can encrypt data onto one associated HDMI output.
•Uses Microsoft UAA driver.
•Internally connected to the integrated HDMI, or HDMI-enabled interface, hence no external cable required.
•Support for basic audio (32, 44.1 or 48 KHz stereo) and AC3 or DTS at the same sample rates.
1.2.13 System Clocks
Support for an external clock chip to generate side-port memory, PCIe, and A-Link Express II clocks.
•
1.2.14 Power Management Features
•
Single chip solution in 55nm, 1.1V CMOS technology.
•Full ACPI 2.0 and IAPC (Instantly Available PC) power management support.
•Static and dynamic power management support (APM as well as ACPI) with full VESA DPM and Energy Star
compliance.
•The Chip Power Management Support logic supports four device power states defined for the OnNow Architecture—
On, Standby, Suspend, and Off. Each power state can be achieved by software control bits.
•Hardware controlled intelligent clock gating enables clocks only to active fun ctional blocks, and is completely
transparent to software.
•Dynamic self-refresh for the side-port memory.
•Support for Cool'n'Quiet™ via FID/VID change.
•Support for AMD PowerNow!™.
•Clocks to every major functional block are controlled by a unique dynamic clock switching technique that is
completely transparent to the software. By turning off the clock to the block that is idle or not used at that point, the
power consumption can be significantly reduced during normal operation.
•Supports AMD Vari-Bright™ technology.
•Supports dynamic lane reduction for the PCIe graphics interface when coupled with an AMD-based graphics device,
adjusting lane width according to required bandwidth.
RS880 Features
1.2.15 PC Design Guide Compliance
The RS880 complies with all relevant Windows Logo Program (WLP) requirements from Microsoft for WHQL
certification.
1.2.16 Test Capability Features
The RS880 has a variety of test modes and capabilities that provide a very high fault coverage and low DPM (Defect Per
Million) ratio:
•Full scan implementation on the digital core logic through ATPG (Automatic Test Pattern Generation Vecto rs).
•Dedicated test logic for the on-chip custom memory macros to provide complete coverage on these modules.
•A JTAG test mode to allow board level testing of neighboring devices.
•An EXOR tree test mode on all the digital I/O's to allow for proper soldering verification at the board level.
•A VOH/VOL test mode on all digital I/O’s to allow for proper verification of output high and output low values at the
board level.
•Access to the analog modules to allow full evaluation and characterization.
•IDDQ mode support to allow chip evaluation through current leakage measurements.
These test modes can be accessed through the settings on the instruction register of the JTAG circuitry.
1.2.17 Packaging
•
Single chip solution in 55nm, 1.1V low power CMOS technology.
•528-FCBGA package, 21mmx21mm.
1.3Software Features
•Supports Microsoft Windows XP, Windows Vista, and Windows 7.
•BIOS ability to read EDID 1.1, 1.2, and 1.3.
•Ability to selectively enable and disable several devices including CRT, LCD, and DFP.
•Register-compatible with VGA standards, BIOS-compatible with VESA VBE2.0.
•Supports corporate manageability requirements such as DMI.
•ACPI support.
•Full Write Combining support for maximum performance of the CPU.
•Full-featured, yet simple Windows utilities:
•Calibration utility for WYSIWYG color
•Independent brightness control of desktop and overlay
•End user diagnostics
•Drivers meet Microsoft's rigorous WHQL criteria and are suitable for systems with the "Designed for Windows"
logos.
•Comprehensive OS and API support.
•Hot-key support (Windows ACPI 2.0 or AMD Event Handler Utility where appropriate).
•Extensive power management support.
•Rotation mode support in software.
•Dual CRTC, simultaneous view, extended desktop support (Windows XP, Windows Vista, and Windows 7)
•DirectX 10.1 support.
•Switchable overlay support.
•H.264 playback support.
•Supports AMD OverDrive™ utility.
***Warning*** AMD and ATI processors are intendedto be operated only within their associated specifications and factory settings. Operating the AMD or ATI processor outside of specification or in
excess of factory settings, including but not limited to overclocking, may damage the processor and/or lead to other problems, including but not limited to, damage to the system components (including the
motherboard and components thereon (e.g. memory)), system instabilities (e.g. data loss and corrupted images), shortened processor, system component and/or system life and in extreme cases, total
system failure. AMD does not provide support or service for issues or damages related to use of an AMD or ATI processor outside of processor specifications or in excess of factory settings.
•Supports Hybrid CrossFire™.
1.4Branding Diagrams
Note: The branding can be in laser, ink, or mixed laser-and-ink marking.
Graphics Device ID and Graphics Engine Clock Speed
RADEON IGP
YYWW
MADE IN TAIWANWXXXXX
215-0752001
Part Number
Date Code (“YY” - Year, ”ZZ” - Week)
AMD Product Type
AMD Logo
Wafer Lot Number (“ZZ” may not be shown)
Country of Origin (China or Taiwan)
Note: Branding can be in laser, ink, or
mixed laser-and-ink marking.
WWWXXX.ZZ
MADE IN COO
Figure 1-3 RS880 ASIC A11 Production Branding
1.5Graphics Device ID and Graphics Engine Clock Speed
Table 1-2 Graphics Device ID and Graphics Engine Clock Speed
1.6Conventions and Notations
The following conventions are used throughout this manual.
1.6.1Pin Names
Pins are identified by their pin names or ball references. Multiplexed pins sometimes assume alternate “functional names”
when they perform their alternate functions, and these “functional names” are given in Chapter 3, “Pin Descriptions and
Strap Options.”
All active-low signals are identified by the suffix ‘#’ in their names (e.g., MEM_RAS#).
1.6.2Pin Types
The pins are assigned different codes according to their operational characteristics. These codes are listed in Table 1-3.
Table 1-3 Pin Type Codes
IDigital Input
ODigital Output
ODOpen Drain
I/OBi-Directional Digital Input or Output
I/ODDigital Input or Open Drain
MMultifunctional
PwrPower
GndGround
A-OAnalog Output
A-IAnalog Input
A-I/OAnalog Bi-Directional Input/Output
A-PwrAnalog Power
A-GndAnalog Ground
OtherPin types not included in any of the categories above
1.6.3Numeric Representation
Hexadecimal numbers are appended with “h” (Intel assembly-style notation) whenever there is a risk of ambiguity. Other
numbers are in decimal.
Pins of identical functions but different running integers (e.g., “GFX_TX7P, GFX_TX6P,... GFX_TX0P”) are referred to
collectively by specifying their integers in square brackets and with colons (i.e., “GFX_TX[7:0]P”). A similar short-hand
notation is used to indicate bit occupation in a register. For example, NB_COMMAND[15:10] refers to the bit positions
10 through 15 of the NB_COMMAND register.
1.6.4 Register Field
A field of a register is referred to by the format of [Register Name].[Register.Field]. For example,
“NB_MC_CNTL.DISABLE_BYPASS” is the “DISABLE_BYPASS” field of the register “NB_MC_CNTL.”
1.6.5 Hyperlinks
Phrases or sentences in blue italicfont are hyperlinks to other parts of the manual. Users of the PDF version of this manual
can click on the links to go directly to the referenced sections, tables, or figures.
1.6.6Acronyms and Abbreviations
The following is a list of the acronyms and abbreviations used in this manual.
Table 1-4 Acronyms and Abbreviations
AcronymFull Expression
ACPIAdvanced Configuration and Power Interface
A-Link-EA-Link Express interface between the IGP and the Southbridge.
BGABall Grid Array
BIOS
BISTBuilt In Self Test.
BLTBlit
bppbits per pixel
CECConsumer Electronic Control
CPISCommon Panel Interface Specification
CRTCathode Ray Tube
CSPChip Scale Package
DACDigital to Analog Converter
DBIDynamic Bus Inversion
DDC
DDRDouble Data Rate
DFPDigital Flat Panel. Monitor connection standard from VESA.
DPDisplayPort
DPMDefects per Million
DTVDigital TV
Basic Input Output System. Initialization code stored in a ROM or Flash RAM used to start up a
system or expansion card.
Display Data Channel. A VESA standard for communicating between a computer system and
attached display devices.
interface. For a detailed description of the interface, please refer to the
interface. This section presents
Host Interface
HT Interface to CPU (PHY)
Configuration
Registers
Root Complex
Memory Controller
LTA
LRA
SCH
Data Link Layer
Protocol/Transacti o n La ye r
HyperTransport I/O Link Specification from the HyperTransport Consortium. Figure 2-2, “Host Interface Block
Diagram,” illustrates the basic blocks of the host bus interface of the RS880.
Figure 2-2 Host Interface Block Diagram
The HyperTransport (HT) Interface, formerly known as the LDT (Lightning Data Transport) interface, is a high speed,
packet-based link implemented on two unidirectional buses. It is a point-to-point interface where data can flow both
upstream and downstream at the same time. The commands, addresses, and data travel in packets on the HyperTransport
link. Lengths of packets are in multiples of four bytes. The HT link consists of three parts: the physical layer (PHY), the
data link layer, and the protocol/transaction layer. The PHY is the physical interface between the RS880 and the CPU.
The data link layer includes the initialization and configuration sequences, periodic redundancy checks,
connect/disconnect sequences, and information packet flow controls. The protocol layer is responsible for maintaining
strict ordering rules defined by the HT protocol.
The RS880 HyperTransport bus interface consists of eighteen unidirectional differential data/control pairs and two
differential clock pairs in each of the upstream and downstream direction. On power up, the HT link is 8-bit wide and runs
at a default speed of 400MT/s. After negotiation, carried out by the HW and SW together, the link width can be brought
up to 16-bit and the interface can run up to 4.4GT/s. The interface is illustrated in Figure 2-3, “RS880 Host Bus Interface
Signals.” The signal name and direction for each signal is shown with respect to the processor. Note that the signal names
may be different from those used in the pin listing of the RS880. Detailed descriptions of the signals are given in section
3.3, “CPU HyperTransport™ Interface‚’ on page 3-5.
In order to significantly decrease system power and increase graphics performance, the RS880 provides an optional
side-port memory interface for dedicated frame buffer memory, to be used exclusively for the integrated graphics core.
The side-port memory interface can significantly reduce system power by allowing the CPU to stay in its lowest power
state during periods of inactivity. Screen refreshes are fetched from the side-port memory, and there is no need to "wake
up" the CPU to fetch screen refresh data.
The RS880 memory controller is unique and highly optimized. It operates in 16-bit mode at very high speed (up to
DDR2-800 and DDR3-1200), and has a programmable interleaved mode that significantly increases the memory
bandwidth and reduces data latency to the integrated graphics core. The additional bandwidth provided to the internal
graphics core will also aid the RS880 in reaching and exceeding Microsoft's Windows Vista
requirements.
2.2.1 DDR2 Memory Interface
Figure 2-4, “RS880 Side-Port Memory Interface,” on page 2-4 illustrates the side-port memory interface of the RS880.
RS880 memory controller features and limitations:
•Supports a single memory device up to 128MB of physical size. However, as the memory interface is
optimized for a 64MB local frame buffer, the system BIOS will downsize the side-port memory if a 128MB
memory device is populated.
•Controls a single rank of DDR2 devices in 16-bit memory configuration.
•Supports device sizes of 256, 512, and 1024 Mbits, and a device width of x16.
•As the memory controller supplies only one chip select signal, only devices with one chip selec t are supp orte d.
•A wide range of DDR2 timing parameters, configurations, and loadings are programmable via the RS880
The memory controller supports DDR2 SDRAM chips in several configurations. These chips are organized in banks,
rows (or pages), and columns. The supported DDR2 components have four or eight banks. Table 2-1 lists the supported
memory components.
•Supports a single memory device up to 128MB of physical size. However, as the memory interface is
optimized for a 64MB local frame buffer, the system BIOS will downsize the side-port memory if a 128MB
memory device is populated.
•Supports a single rank of DDR3 device in 16-bit memory configuration.
•Supports device sizes of 512 and 1024 Mbits, and a device width of x16.
Address
64Mbx16 devices
128Mbx16 devices
•A wide range of DDR3 timing parameters, configurations, and loadings are programmable via the RS880 memory
controller configuration registers.
2.2.2.1 Supported DDR3 Components
The memory controller supports DDR3 SDRAM chips in several configurations. These chips are organized in banks,
rows (or pages), and columns. Table 2-3 lists the supported memory components.
Table 2-3 Supported DDR3 Components
DDR3 SDRAM
ConfigMbitsCS Mode Bank Bits Row BitsCol Bits
32Mbx1651293121064
64Mbx1610241131310128
2.2.2.2 Row and Column Addressing
Table 2-4 shows how the physical address P (after taking out the bank bit) is used to provide the row and column