Mode Register Set MRS and Emrs | Texas Instruments TMS320C6455

Peripheral Architecture

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2.4.1Mode Register Set (MRS and EMRS)

DDR2 SDRAM contains mode and extended mode registers that configure the DDR2 memory for operation. These registers control burst type, burst length, CAS latency, DLL enable/disable, single-ended strobe, etc.

The DDR2 memory controller programs the mode and extended mode registers of the DDR2 memory by issuing MRS and EMRS commands. When the MRS or EMRS command is executed, the value on DBA[1:0] selects the mode register to be written and the data on DEA[12:0] is loaded into the register. Figure 3 shows the timing for an MRS and EMRS command.

The DDR2 memory controller only issues MRS and EMRS commands during the DDR2 memory controller initialization sequence. For more information, see Section 2.11.

Figure 3. DDR2 MRS and EMRS Command

MRS/EMRS

DDR2CLKOUT

DDR2CLKOUT

DSDCKE
DCE0
DSDRAS
DSDCAS
DSDWE
DEA[13:0]	COL
DBA[2:0]	BANK

14	C6455/C6454 DDR2 Memory Controller	SPRU970G – December 2005 – Revised June 2011
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Texas Instruments TMS320C6455 manual Mode Register Set MRS and Emrs, DDR2 MRS and Emrs Command

Contents

Users Guide Submit Documentation Feedback Contents List of Figures List of Tables Submit Documentation Feedback Read This First Read This First Purpose of the Peripheral FeaturesFunctional Block Diagram Industry Standards Compliance Statement Memory Map Signal DescriptionsClock Control DDR2 Memory Controller Signal Descriptions Pin Description Command Function DDR2 Sdram CommandsTruth Table for DDR2 Sdram Commands Protocol Descriptions Mode Register Set MRS and Emrs DDR2 MRS and Emrs Command Refresh Mode Refresh Command Actv Command Activation Actv Dcab Command Deactivation Dcab and Deac Deac Command Read Command DDR2 Read Command Addressable Memory Ranges Write WRT CommandMemory Width, Byte Alignment, and Endianness Address Type Generated by DDR2 Bit Field Bit Value Bit Description Bank Configuration Register Fields for Address MappingAddress Mapping Ibank Logical Address-to-DDR2 Sdram Address Map for 32-Bit Sdram Logical Address-to-DDR2 Sdram Address Map DDR2 Memory Controller Interface DDR2 Memory Controller Fifo Description DDR2 Memory Controller Fifo Block Diagram Command Ordering and Scheduling, Advanced Concept Command Starvation Refresh Urgency Levels Refresh SchedulingPossible Race Condition Urgency Level Description Device and DDR2 Memory Controller Reset Relationship Self-Refresh ModeReset Considerations DDR2 Memory Controller Reset Effect Initiated by DDR2 Sdram Extended Mode Register 1 Configuration 11.1 DDR2 Sdram Device Mode Register Configuration ValuesDDR2 Sdram Mode Register Configuration Mode Register Field Interrupt Support 11.2 DDR2 Sdram Initialization After Reset11.3 DDR2 Sdram Initialization After Register Configuration Edma Event Support Using the DDR2 Memory Controller Connecting the DDR2 Memory Controller to DDR2 Sdram Connecting to Two 16-Bit DDR2 Sdram Devices Connecting to a Single 16-Bit DDR2 Sdram Device Connecting to Two 8-Bit DDR2 Sdram Devices Programming the Sdram Refresh Control Register Sdrfc Programming the Sdram Configuration Register SdcfgSdcfg Configuration Field Configuring Sdram Timing Registers SDTIM1 and SDTIM2 DDR2 Memory Refresh SpecificationSdrfc Configuration SDTIM1 Configuration DDR2 Sdram Data Register Field Sheet Parameter SDTIM2 ConfigurationDmcctl Configuration Name Description Register Description DDR2 Memory Controller RegistersOffset Bit Field Value Description Module ID and Revision Register MidrModule ID and Revision Register Midr Field Descriptions DDR2 Memory Controller Status Register Dmcstat Ifrdy Sdram Configuration Register Sdcfg Sdram Configuration Register Sdcfg Field Descriptions Sequence. Values 4-7 are reserved for this field Sdram Refresh Control Register Sdrfc Sdram Refresh Control Register Sdrfc Field Descriptions Trfc TRP Trcd TWR Sdram Timing 1 Register SDTIM1Sdram Timing 1 Register SDTIM1 Field Descriptions Tras TRC Trrd Using this formula Todt Txsnr Sdram Timing 2 Register SDTIM2Sdram Timing 2 Register SDTIM2 Field Descriptions Txsrd Trtp Tcke Prioraise Burst Priority Register BprioBurst Priority Register Bprio Field Descriptions DDR2 Memory Controller Control Register Dmcctl DDR2 Memory Controller Control Register Dmcctl Revision History Rfid Products ApplicationsDSP TI E2E Community Home