Texas Instruments SPRU938B manual Clock Control, External Clock Block Diagram

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Peripheral Architecture

2Peripheral Architecture

This section discusses the architecture and basic functions of the VLYNQ peripheral.

2.1Clock Control

The module'sserial clock direction and frequency are software configurable through the CLKDIR and CLKDIV bits in the VLYNQ control register (CTRL). The VLYNQ serial clock can be sourced from the internal system clock (CLKDIR = 1) or by an external clock source (CLKDIR = 0) for its serial operations.

The CLKDIV bit can divide the serial clock (1/1 - 1/8) down when the internal clock is selected as the source. The serial clock is not affected by the CLKDIV bit values, if the serial clock is externally sourced.

The reset value of the CLKDIR bit is 0 (external clock source).

The external clock source is shown in Figure 2. The internal clock source is shown in Figure 3.

 

Figure 2. External Clock Block Diagram

DMxxx￿device

VLYNQ￿device

VLYNQ

CLKDIR=0

VLYNQ

 

VLYNQ_CLK

 

CLKDIR=0

Figure 3. Internal Clock Block Diagram

DMxxx￿device

 

VLYNQ

CLKDIR=1

 

VLYNQ

 

internal

 

sys￿clk

VLYNQ_CLK

VLYNQ￿device

CLKDIR=1

VLYNQ

Don’t

care

10

VLYNQ Port

SPRU938B –September 2007

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Contents Users Guide Submit Documentation Feedback Contents Appendix B Appendix CList of Figures List of Tables Read This First Features Purpose of the PeripheralFunctional Block Diagram Industry Standards Compliance StatementExternal Clock Block Diagram Clock ControlPin Multiplexing Signal DescriptionsVlynq Signal Descriptions Protocol DescriptionVlynq Functional Description Vlynq Module StructureWrite Operations Read Operations Initialization Auto-NegotiationAddress Translation Address Translation Example Single Mapped Region Register DM643x Vlynq ModuleDM643x Vlynq Module Remote Vlynq ModuleFlow Control Example 1. Address Translation ExampleHardware Reset Considerations Reset ConsiderationsSoftware Reset Considerations Interrupt SupportInterrupt Generation Mechanism Block Diagram Writes to Interrupt Pending/Set RegisterEdma Event Support Serial Bus Error InterruptsRemote Interrupts Endianness Considerations Power ManagementEmulation Considerations Block Name Start Address End Address Size Vlynq Register Address SpaceVlynq Port Controller Registers Acronym Register DescriptionRevmaj Revmin Revision Register RevidRevision Register Revid Field Descriptions Bit Field Value DescriptionControl Register Ctrl Control Register Ctrl Field DescriptionsAoptdisable Bit FieldStatus Register Stat Status Register Stat Field DescriptionsNo error LerrorNointpend Interrupt Priority Vector Status/Clear Register IntpriInterrupt Status/Clear Register Intstatclr InstatInterrupt Pointer Register Intptr Field Descriptions Interrupt Pending/Set Register IntpendsetInterrupt Pointer Register Intptr IntsetAddress Map Register XAM Field Descriptions Transmit Address Map Register XAMTxadrmap RXADRSIZE1 Receive Address Map Size 1 Register RAMS1Receive Address Map Offset 1 Register RAMO1 RXADROFFSET1RXADRSIZE2 Receive Address Map Size 2 Register RAMS2Receive Address Map Offset 2 Register RAMO2 RXADROFFSET2RXADRSIZE3 Receive Address Map Size 3 Register RAMS3Receive Address Map Offset 3 Register RAMO3 RXADROFFSET3RXADRSIZE4 Receive Address Map Size 4 Register RAMS4Receive Address Map Offset 4 Register RAMO4 RXADROFFSET4Chip Version Register Chipver Field Descriptions Chip Version Register ChipverAuto Negotiation Register Autngo Auto Negotiation Register Autngo Field DescriptionsVlynq Port Remote Controller Registers Supported Ordered Sets IntroductionSpecial 8b/10b Code Groups Table A-1. Special 8b/10b Code GroupsFigure A-1. Packet Format 10-bit Symbol Representation Vlynq 2.0 Packet FormatField Value Description Vlynq 2.X Packets Vlynq 2.X Packets Write Performance Burst Size Interface Running at 76.5 MHZ Bit Words Mbits/sec Mbytes/secThroughput Read PerformanceTable B-3. Relative Performance with Various Latencies Latency μsecTable C-1. Document Revision History Reference Additions/Modifications/DeletionsDSP Products ApplicationsRfid