Texas Instruments VLYNQ Port manual Peripheral Architecture, Clock Control

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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

 

CLKDIR=0

VLYNQ

VLYNQ

 

VLYNQ.CLK

 

CLKDIR=0

Figure 3. Internal Clock Block Diagram

DMxxx￿device

 

VLYNQ￿device

 

CLKDIR=1

 

VLYNQ

 

VLYNQ

VLYNQ

 

 

internal

 

 

sys￿clk

VLYNQ.CLK

Don't

 

 

 

 

care

 

 

CLKDIR=0

SPRUE36A –September 2007

VLYNQ Port

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Contents Users Guide Submit Documentation Feedback Contents Appendix C Appendix BList of Figures List of Tables Related Documentation From Texas Instruments About This DocumentNotational Conventions Trademarks Purpose of the Peripheral FeaturesIntroduction Industry Standards Compliance Statement Functional Block DiagramClock Control Peripheral ArchitectureProtocol Description Signal DescriptionsVlynq Port Pins Pin MultiplexingVlynq Module Structure Vlynq Functional DescriptionTxSM Write OperationsRead Operations Serial Interface Width Serial Interface Width ConfigurationInitialization Auto-NegotiationAddress Translation Register DM644x Vlynq Module Address Translation Example Single Mapped RegionRemote Vlynq Module DM644x Vlynq ModuleExample 1. Address Translation Example Flow ControlInterrupt Support Reset ConsiderationsSoftware Reset Considerations Hardware Reset ConsiderationsWrites to Interrupt Pending/Set Register Interrupt Generation Mechanism Block DiagramRemote Interrupts Serial Bus Error InterruptsDMA Event Support Emulation Considerations Power ManagementBlock Name Start Address End Address Size Vlynq Port RegistersVlynq Register Address Space Vlynq Port Controller RegistersBit Field Value Description Revision Register RevidRevision Register Revid Field Descriptions Revmaj RevminControl Register Ctrl Field Descriptions Control Register CtrlBit Field AoptdisableStatus Register Stat Field Descriptions Status Register StatLerror No errorInstat Interrupt Priority Vector Status/Clear Register IntpriInterrupt Status/Clear Register Intstatclr NointpendIntset Interrupt Pending/Set Register IntpendsetInterrupt Pointer Register Intptr Interrupt Pointer Register Intptr Field DescriptionsTxadrmap Transmit Address Map Register XAMAddress Map Register XAM Field Descriptions RXADROFFSET1 Receive Address Map Size 1 Register RAMS1Receive Address Map Offset 1 Register RAMO1 RXADRSIZE1RXADROFFSET2 Receive Address Map Size 2 Register RAMS2Receive Address Map Offset 2 Register RAMO2 RXADRSIZE2RXADROFFSET3 Receive Address Map Size 3 Register RAMS3Receive Address Map Offset 3 Register RAMO3 RXADRSIZE3RXADROFFSET4 Receive Address Map Size 4 Register RAMS4Receive Address Map Offset 4 Register RAMO4 RXADRSIZE4Auto Negotiation Register Autngo Field Descriptions Chip Version Register ChipverAuto Negotiation Register Autngo Chip Version Register Chipver Field DescriptionsVlynq Port Remote Controller Registers Remote Configuration RegistersTable A-1. Special 8b/10b Code Groups Appendix a Vlynq Protocol SpecificationsSpecial 8b/10b Code Groups Supported Ordered SetsVlynq 2.0 Packet Format Figure A-1. Packet Format 10-bit Symbol RepresentationField Value Description Vlynq 2.X Packets Vlynq 2.X Packets Write Performance Appendix B Write/Read PerformanceBit Words Mbits/sec Mbytes/sec Table B-1. Scaling FactorsBurst Size in 32-bit words Data Bytes Burst Size Interface Running at 76.5 MHZTable B-3. Relative Performance with Various Latencies Read PerformanceAdditions/Modifications/Deletions Appendix C Revision HistoryTable C-1. Document Revision History Rfid Products ApplicationsDSP