Texas Instruments TMS320C642x DSP manual Purpose of the Peripheral, Features

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User's Guide

SPRUEM4A–November 2007

DDR2 Memory Controller

1Introduction

This document describes the DDR2 memory controller in the TMS320C642x Digital Signal Processor (DSP).

1.1Purpose of the Peripheral

The DDR2 memory controller is used to interface with JESD79D-2A standard compliant DDR2 SDRAM devices. Memories types such as DDR1 SDRAM, SDR SDRAM, SBSRAM, and asynchronous memories are not supported. The DDR2 memory controller is the major memory location for program and data storage.

1.2Features

The DDR2 memory controller supports the following features:

∙JESD79D-2A standard compliant DDR2 SDRAM

∙256 Mbyte memory space

∙Data bus width of 32 or 16 bits (see the device-specific data manual for the mode(s) that are supported)

∙CAS latencies: 2, 3, 4, and 5

∙Internal banks: 1, 2, 4, and 8

∙Burst length: 8

∙Burst type: sequential

∙1 CS signal

∙Page sizes: 256, 512, 1024, and 2048

∙SDRAM autoinitialization

∙Self-refresh mode

∙Prioritized refresh

∙Programmable refresh rate and backlog counter

∙Programmable timing parameters

∙Big-endian and little-endian operating modes

SPRUEM4A–November 2007	DDR2 Memory Controller	7
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Contents Users Guide Submit Documentation Feedback Contents List of Figures List of Tables Read This First Purpose of the Peripheral FeaturesSupported Use Case Statement Functional Block DiagramIndustry Standards Compliance Statement Clock Source Clock Control3 DDR2 Memory Controller Internal Clock Domains Clock ConfigurationPLLC2 Configuration Memory MapPin Type Description Signal DescriptionsDDR2 Memory Controller Signal Descriptions Clock enable Active highProtocol Descriptions DDR2 Sdram CommandsTruth Table for DDR2 Sdram Commands Command FunctionRefresh Command Refresh ModeDeactivation Dcab and Deac Dcab CommandDeac Command Activation Actv Actv CommandDDR2 Read Command Read CommandDDR2 WRT Command Write WRT CommandDDR2 MRS and Emrs Command Mode Register Set MRS and EmrsAddressable Memory Ranges Memory Width and Byte AlignmentBit External Memory Endianness SupportAddress Mapping Bank Configuration Register Fields for Address MappingBit Field Bit Value Bit Description Logical Address-to-DDR2 Sdram Address Map for 16-bit Sdram Logical Address-to-DDR2 Sdram Address Map for 32-Bit SdramLogical Address-to-DDR2 Sdram Address Map DDR2 Sdram Column, Row, and Bank Access DDR2 Memory Controller Fifo Description DDR2 Memory Controller InterfaceCommand Ordering and Scheduling, Advanced Concept Possible Race Condition Command StarvationUrgency Level Description Self-Refresh ModeRefresh Scheduling Refresh Urgency LevelsReset Sources Reset ConsiderationsReset Signal Reset Source Auto-Initialization Sequence VTP IO Buffer CalibrationDDR2 Memory Controller DDR2 Sdram Configuration by MRS CommandDDR2 Sdram Configuration by EMRS1 Command Initializing Configuration RegistersPeripheral Architecture Interrupt Support Power ManagementDMA Event Support Emulation Considerations Supported Use Cases Connecting the DDR2 Memory Controller to DDR2 MemoryConnecting DDR2 Memory Controller for 32-Bit Connection DDR2 Memory Refresh Specification Configuring Sdram Bank Configuration Register SdbcrSdram Bank Configuration Register Sdbcr Configuration Configuring Sdram Refresh Control Register SdrcrDDR2 Data Register Field Manual Data Manual Formula Configuring Sdram Timing Registers Sdtimr and SDTIMR2Sdram Timing Register Sdtimr Configuration Sdram Timing Register 2 SDTIMR2 ConfigurationDDR PHY Control Register Ddrphycr Configuration Configuring DDR PHY Control Register DdrphycrRegister Field Name Description DDR VTP Register Mode D63-32D31-0 Acronym Register DescriptionSdram Status Register Sdrstat Field Descriptions Sdram Status Register SdrstatBit Field Sdram Bank Configuration Register Sdbcr Field Descriptions Sdram Bank Configuration Register SdbcrBit Field Value Description Reserved Reserved. Always write a 0 to this bit Sdram Refresh Control Register Sdrcr Field Descriptions Sdram Refresh Control Register SdrcrSdram Timing Register Sdtimr Field Descriptions Sdram Timing Register SdtimrSdram Timing Register 2 SDTIMR2 Field Descriptions Sdram Timing Register 2 SDTIMR2Peripheral Bus Burst Priority Register Pbbpr Peripheral Bus Burst Priority Register PbbprInterrupt Raw Register IRR Field Descriptions Interrupt Raw Register IRRInterrupt Masked Register IMR Field Descriptions Interrupt Masked Register IMRInterrupt Mask Set Register Imsr Field Descriptions Interrupt Mask Set Register ImsrInterrupt Mask Clear Register Imcr Field Descriptions Interrupt Mask Clear Register ImcrDDR PHY Control Register Ddrphycr Field Descriptions DDR PHY Control Register DdrphycrVTP IO Control Register Vtpiocr Field Descriptions VTP IO Control Register VtpiocrDDR VTP Register Ddrvtpr Field Descriptions DDR VTP Enable Register DdrvtperDDR VTP Enable Register Ddrvtper Field Descriptions DDR VTP Register DdrvtprAdditions/Modifications/Deletions Table A-1. Document Revision HistoryImportant Notice