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Texas Instruments TMS320DM643x manual Changing SYSCLK Dividers

Models: TMS320DM643x

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5.3.2.4Changing SYSCLK Dividers

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PLL2 Control

5.3.2.4Changing SYSCLK Dividers

This section discusses the software sequence to change the SYSCLK dividers. The SYSCLK divider change sequence is also referred to as GO operation, as it involves hitting the GO bit (GOSET bit in PLLCMD) to initiate the divider change.

1.Check for the GOSTAT bit in PLLSTAT to clear to 0 to indicate that no GO operation is currently in progress.

2.Program the RATIO field in PLLDIV1 and PLLDIV2 with the desired divide factors. For PLLC2, there is no specific frequency ratio requirements between SYSCLK1 and SYSCLK2. Make sure in this step you leave the PLLDIV1.D1EN and PLLDIV2.D2EN bits set (default).

3.Set the GOSET bit in PLLCMD to 1 to initiate a new divider transition. During this transition, SYSCLK1 and SYSCLK2 are paused momentarily.

4.Wait for N number of PLLDIVn source clock cycles to ensure divider changes have completed. See the following formula for calculating the number of cycles N.

5.Wait for the GOSTAT bit in PLLSTAT to clear to 0.

The following formula should be used to calculate the number of PLLDIVn source clock cycles:

N = (2 × Least Common Multiple [LCM] of all the old SYSCLK divide values) + 50 cycles overhead

Example 5-2. Calculating Number of Clock Cycles N

This example calculates the number of clock cycles N.

∙Settings before divider change:

–PLLDIV1.RATIO = 1 (divide-by-2)

–PLLDIV2.RATIO = 9 (divide-by-10)

∙New divider settings:

–PLLDIV1.RATIO = 1 (divide-by-2)

–PLLDIV2.RATIO = 19 (divide-by-20)

The least common multiple between the old divider values of /2 and /10 is /10; therefore, the number of cycles N is:

N = (2 × 10) + 50 cycles overhead = 70 PLLDIVn source clock cycles

If PLLC2 is in PLL mode (PLLCTL.PLLEN = 1), the PLLDIVn source clock is the PLL2 output clock. If PLLC2 is in PLL bypass mode (PLLCTL.PLLEN = 0), the PLLDIVn source clock is the device clock source MXI/CLKIN.

SPRU978E–March 2008

PLL Controller

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Texas Instruments TMS320DM643x manual Changing SYSCLK Dividers, Example 5-2. Calculating Number of Clock Cycles N

Contents

TMS320DM643x DMP DSP Subsystem Reference GuideSubmit Documentation Feedback SPRU978E-MarchContents 6.7.3 Module Error Pending Register 1 MERRPR1 Boot Modes ResetList of Figures List of Tables List of TablesSubmit Documentation Feedback List of TablesSPRU978E-March Notational Conventions Read This FirstPreface About This ManualSubmit Documentation Feedback TMS320C6000, C6000 are trademarks of Texas InstrumentsRead This First SPRU978E-MarchIntroduction Block DiagramIntroduction Chapter1.1 Introduction 1.2 Block DiagramFigure 1-1. TMS320DM643x DMP Block Diagram 1.3.1 Components of the DSP Subsystem 1.3 DSP Subsystem in TMS320DM643x DMPSubmit Documentation Feedback IntroductionSPRU978E-March Internal Peripherals TMS320C64x+ MegamoduleTMS320C64x+ CPU Memory Controllers2.2 TMS320C64x+ CPU 2.1 IntroductionFigure 2-1. TMS320C64x+ Megamodule Block Diagram 2.3.1 L1P Controller 2.3 Memory ControllersMemory Controllers Figure 2-2. C64x+ Cache Memory Architecture2.3.3 L2 Controller 2.3.2 L1D Controller2.3.5 Internal DMA IDMA 2.3.4 External Memory Controller EMC2.4.1 Interrupt Controller INTC 2.4.2 Power-Down Controller PDC2.4 Internal Peripherals 2.4.3 Bandwidth Manager Submit Documentation Feedback TMS320C64x+ MegamoduleSPRU978E-March Chapter System MemoryMemory Map Memory Interfaces Overview3.1.3 Internal Peripherals 3.1 Memory Map3.1.1 DSP Internal Memory L1P, L1D, L2 3.1.2 External Memory3.2.2.1 Asynchronous EMIF Interface 3.2 Memory Interfaces Overview3.2.1 DDR2 External Memory Interface 3.2.2 External Memory InterfaceSubmit Documentation Feedback System MemorySPRU978E-March Chapter Device ClockingOverview Clock DomainsTable 4-1. System Clock Modes and Fixed Ratios for Core Clock Domains 4.1 Overview4.2 Clock Domains 4.2.1 Core DomainsClock Domains Figure 4-1. Overall Clocking DiagramTable 4-2. Example PLL1 Frequencies and Dividers 27 MHZ Clock Input 4.2.2 Core Frequency FlexibilityTable 4-4. Example PLL2 Frequencies Core Voltage = 4.2.3 DDR2/EMIF ClockTable 4-3. Example PLL2 Frequencies Core Voltage = Table 4-5. Peripheral I/O Domain Clock 4.2.4 I/O DomainsFigure 4-2. VPBE/DAC Clocking 4.2.5 Video Processing Back EndVPSSCLKCTL.MUXSEL Bit Clocking ModeTable 4-6. Possible Clocking Modes Clock DomainsPLL2 Control PLL ControllerPLL Module PLL1 Control5.2 PLL1 Control 5.1 PLL ModuleTable 5-1. System PLLC1 Output Clocks 5.2.1 Device Clock Generation5.2.2 Steps for Changing PLL1/Core Domain Frequency Figure 5-1. PLL1 Structure in the TMS320DM643x DMP5.2.2.1 Initialization to PLL Mode from PLL Power Down 5.2.2.2 Changing PLL Multiplier Example 5-1. Calculating Number of Clock Cycles N 5.2.2.3 Changing SYSCLK DividersTable 5-2. DDR PLLC2 Output Clocks 5.3 PLL2 Control5.3.1 Device Clock Generation Figure 5-2. PLL2 Structure in the TMS320DM643x DMP5.3.2 Steps for Changing PLL2 Frequency 5.3.2.1 DDR2 Considerations When Modifying PLL2 Frequency5.3.2.2 Initialization to PLL Mode from PLL Power Down 5.3.2.3 Changing PLL Multiplier Example 5-2. Calculating Number of Clock Cycles N 5.3.2.4 Changing SYSCLK Dividers5.4 PLL Controller Registers Table 5-3. PLL and Reset Controller ListTable 5-4. PLL and Reset Controller Registers PLL and Reset Controller5.4.1 Peripheral ID Register PID 5.4.2 Reset Type Status Register RSTYPEFigure 5-4. Reset Type Status Register RSTYPE Table 5-6. Reset Type Status Register RSTYPE Field DescriptionsPLL Controller Registers 5.4.3 PLL Control Register PLLCTLFigure 5-5. PLL Control Register PLLCTL Table 5-7. PLL Control Register PLLCTL Field DescriptionsTable 5-8. PLL Multiplier Control Register PLLM Field Descriptions 5.4.4 PLL Multiplier Control Register PLLM5.4.5 PLL Controller Divider 1 Register PLLDIV1 Figure 5-6. PLL Multiplier Control Register PLLMFigure 5-9. PLL Controller Divider 3 Register PLLDIV3 5.4.6 PLL Controller Divider 2 Register PLLDIV25.4.7 PLL Controller Divider 3 Register PLLDIV3 Figure 5-8. PLL Controller Divider 2 Register PLLDIV2PLL Controller Registers 5.4.8 Oscillator Divider 1 Register OSCDIV1Figure 5-10. Oscillator Divider 1 Register OSCDIV1 Table 5-12. Oscillator Divider 1 Register OSCDIV1 Field DescriptionsPLL Controller Registers 5.4.9 Bypass Divider Register BPDIVFigure 5-11. Bypass Divider Register BPDIV Table 5-13. Bypass Divider Register BPDIV Field Descriptions5.4.11 PLL Controller Status Register PLLSTAT 5.4.10 PLL Controller Command Register PLLCMDFigure 5-12. PLL Controller Command Register PLLCMD Table 5-14. PLL Controller Command Register PLLCMD Field DescriptionsField 5.4.12 PLL Controller Clock Align Control Register ALNCTLFigure 5-14. PLL Controller Clock Align Control Register ALNCTL PLL Controller RegistersField 5.4.13 PLLDIV Ratio Change Status Register DCHANGEFigure 5-15. PLLDIV Ratio Change Status Register DCHANGE PLL Controller RegistersPLL Controller Registers 5.4.14 Clock Enable Control Register CKENFigure 5-16. Clock Enable Control Register CKEN Table 5-18. Clock Enable Control Register CKEN Field DescriptionsPLL Controller Registers 5.4.15 Clock Status Register CKSTATFigure 5-17. Clock Status Register CKSTAT Table 5-19. Clock Status Register CKSTAT Field DescriptionsPLL Controller Registers 5.4.16 SYSCLK Status Register SYSTATFigure 5-18. SYSCLK Status Register SYSTAT Table 5-20. SYSCLK Status Register SYSTAT Field DescriptionsExecuting State Transitions Power and Sleep ControllerPower Domain and Module Topology Power Domain and Module States6.1 Introduction Figure 6-1. Power and Sleep Controller PSC IntegrationTable 6-1. DM643x DMP Default Module Configuration 6.2 Power Domain and Module TopologyTable 6-2. Module States 6.3 Power Domain and Module States6.3.1 Power Domain States 6.3.2 Module States6.4.2 Module State Transitions 6.3.3 Local Reset6.4.1 Power Domain State Transitions 6.4 Executing State Transitions6.6.1 Interrupt Events Table 6-3. IcePick Emulation Commands6.5 IcePick Emulation Support in the PSC 6.6 PSC Interrupts6.6.1.1 Module State Emulation Events 6.6.1.2 Local Reset Emulation Events6.6.2 Interrupt Registers 6.7 PSC Registers Table 6-5. Power and Sleep Controller PSC Registers6.6.3 Interrupt Handling Figure 6-3. Interrupt Evaluation Register INTEVAL 6.7.1 Peripheral Revision and Class Information Register PID6.7.2 Interrupt Evaluation Register INTEVAL Figure 6-2. Peripheral Revision and Class Information Register PIDTable 6-8. Module Error Pending Register 1 MERRPR1 Field Descriptions 6.7.3 Module Error Pending Register 1 MERRPR16.7.4 Module Error Clear Register 1 MERRCR1 Figure 6-4. Module Error Pending Register 1 MERRPR1Figure 6-7. Power Domain Transition Status Register PTSTAT 6.7.5 Power Domain Transition Command Register PTCMD6.7.6 Power Domain Transition Status Register PTSTAT Figure 6-6. Power Domain Transition Command Register PTCMDPower and Sleep Controller 6.7.7 Power Domain Status 0 Register PDSTAT0Figure 6-8. Power Domain Status 0 Register PDSTAT0 Table 6-12. Power Domain Status 0 Register PDSTAT0 Field DescriptionsPower and Sleep Controller 6.7.8 Power Domain Control 0 Register PDCTL0Figure 6-9. Power Domain Control 0 Register PDCTL0 Table 6-13. Power Domain Control 0 Register PDCTL0 Field DescriptionsTable 6-14. Module Status n Register MDSTATn Field Descriptions Power and Sleep Controller6.7.9 Module Status n Register MDSTATn Figure 6-10. Module Status n Register MDSTATnTable 6-15. Module Control n Register MDCTLn Field Descriptions Power and Sleep Controller6.7.10 Module Control n Register MDCTLn Figure 6-11. Module Control n Register MDCTLnSubmit Documentation Feedback Power and Sleep ControllerSPRU978E-March Video DAC Power Down Power ManagementDSP Sleep Mode Management 3.3 V I/O Power Down7.2 PSC and PLLC Overview Table 7-1. Power Management Features7.1 Overview 7.3.2 Module Clock Frequency Scaling 7.3.3 PLL Bypass and Power Down7.3 Clock Management 7.3.1 Module Clock ON/OFF7.4.2.1 DSP Module Clock ON 7.4 DSP Sleep Mode Management7.4.1 DSP Sleep Modes 7.4.2 DSP Module Clock ON/OFF7.4.2.2 DSP Module Clock Off 7.5 3.3 V I/O Power Down7.6 Video DAC Power Down Submit Documentation Feedback Power ManagementSPRU978E-March Interrupt Controller Interrupt ControllerChapter Submit Documentation Feedback Interrupt ControllerSPRU978E-March System Module Device Configuration3.3 V I/O Power-Down Control Boot Control9.2 Device Identification 9.3 Device Configuration9.3.2 Device Boot Configuration Status 9.1 Overview9.5.2 VPSS Clock and DAC Control 9.4 3.3 V I/O Power-Down Control9.5.1 Timer Control 9.5 Peripheral Status and ControlTable 9-1. TMS320DM643x DMP Master IDs 9.6 Bandwidth Management9.6.1 Bus Master DMA Priority Control Table 9-2. TMS320DM643x DMP Default Master Priorities 9.6.2 EDMA Transfer Controller Configuration9.7 Boot Control Submit Documentation Feedback System ModuleSPRU978E-March DSP Reset ResetReset Pins Device Configurations at Reset10.1 Overview 10.2 Reset Pins10.3 Device Configurations at Reset Table 10-1. Reset Types10.4.2.1 Software Reset Disable SwRstDisable 10.4 DSP Reset10.4.1 DSP Local Reset 10.4.2 DSP Module Reset10.4.2.2 Synchronous Reset SyncReset Chapter Boot ModesSubmit Documentation Feedback Boot ModesSPRU978E-March SPRU978E-March Revision HistoryAppendix A Table A-1. Document Revision HistoryApplications power.ti.comIMPORTANT NOTICE Products