Mdio Clock Generator | Texas Instruments TMS320DM643X DMP guide

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Figure 9. MDIO Module Block Diagram
Peripheral	MDIO
clock	MDIO
clock	clock
	clock
	generator	MDIO
USERINT		MDIO
USERINT		interface
EMAC
control
module
LINKINT	PHY	PHY
	monitoring	polling
	Control
Configuration bus	registers
	and logic

Peripheral Architecture

MDCLK

MDIO

2.7.1.1MDIO Clock Generator

The MDIO clock generator controls the MDIO clock based on a divide-down of the peripheral clock (PLL1/6) in the EMAC control module. The MDIO clock is specified to run up to 2.5 MHZ, although typical operation would be 1.0 MHZ. Since the peripheral clock frequency is variable (PLL1/6), the application software or driver controls the divide-down amount.

2.7.1.2Global PHY Detection and Link State Monitoring

The MDIO module continuously polls all 32 MDIO addresses in order to enumerate the PHY devices in the system. The module tracks whether or not a PHY on a particular address has responded, and whether or not the PHY currently has a link. Using this information allows the software application to quickly determine which MDIO address the PHY is using.

2.7.1.3Active PHY Monitoring

Once a PHY candidate has been selected for use, the MDIO module transparently monitors its link state by reading the MDIO PHY link status register (LINK). Link change events are stored on the MDIO device and can optionally interrupt the CPU. This allows the system to poll the link status of the PHY device without continuously performing costly MDIO accesses.

2.7.1.4PHY Register User Access

When the CPU must access MDIO for configuration and negotiation, the PHY access module performs the actual MDIO read or write operation independent of the CPU. This allows the CPU to poll for completion or receive an interrupt when the read or write operation has been performed. The user access registers USERACCESSn allows the software to submit the access requests for the PHY connected to the device.

SPRU941A –April 2007Ethernet Media Access Controller (EMAC)/ 29

Submit Documentation Feedback	Management Data Input/Output (MDIO)

Image 29

Texas Instruments TMS320DM643X DMP manual Mdio Clock Generator, Global PHY Detection and Link State Monitoring

Contents

Users Guide Submit Documentation Feedback Contents MAC Hash Address Register 1 MACHASH1 Appendix B Appendix a List of Figures Transmit Pacing Algorithm Test Register Tpacetest List of Tables Fifo Control Register Fifocontrol Field Descriptions Read This First Purpose of the Peripheral Features Emac and Mdio Block Diagram Functional Block Diagram Industry Standards Compliance Statement Signal DescriptionsClock Control Memory Map Signal Type Description Emac and Mdio Signals Ethernet Frame Format Ethernet Protocol OverviewEthernet Frame Description Field Bytes Description Packet Buffer Descriptors Ethernet’s Multiple Access ProtocolProgramming Interface Typical Descriptor Linked List Basic Descriptor Description Transmit and Receive Descriptor Queues Transmit and Receive Emac Interrupts Example 1. Transmit Buffer Descriptor in C Structure Format Transmit Buffer Descriptor Format Buffer Pointer Next Descriptor PointerBuffer Offset Buffer Length Ownership Owner Flag End of Packet EOP FlagEnd of Queue EOQ Flag Teardown Complete Tdowncmplt Flag Receive Buffer Descriptor Format Receive Buffer Descriptor Format #define Emacdscflagjabber Example 2. Receive Buffer Descriptor in C Structure Format Buffer Length Alignment Error Alignerror Flag Code Error Codeerror FlagCRC Error Crcerror Flag Jabber Flag No Match Nomatch Flag Emac Control ModuleInternal Memory Bus Arbiter Mdio Module Components Mdio ModuleInterrupt Control Mdio Clock Generator PHY Register User AccessGlobal PHY Detection and Link State Monitoring Active PHY Monitoring Mdio Module Operational Overview Reading Data From a PHY Register Initializing the Mdio ModuleWriting Data To a PHY Register Example 3. Mdio Register Access Macros Example of Mdio Register Access Code Emac Module Components Emac ModuleReceive DMA Engine Receive Fifo Transmit DMA Engine Clock and Reset LogicTransmit Fifo MAC Transmitter Data Reception Media Independent Interface MIIReceive Control Receive Inter-Frame Interval Ieee 802.3x-Based Receive Buffer Flow Control Collision-Based Receive Buffer Flow Control CRC Insertion Transmit ControlAdaptive Performance Optimization APO Interpacket-Gap IPG Enforcement Speed, Duplex, and Pause Frame Support Transmit Flow Control Packet Receive Operation Receive DMA Host ConfigurationReceive Channel Enabling Receive Address Matching Receive Channel Teardown Hardware Receive QOS SupportHost Free Buffer Tracking Receive Frame Classification Promiscuous Receive Mode Receive Frame Treatment Receive Frame Treatment Summary Middle of Frame Overrun Treatment Receive OverrunMiddle of Frame Overrun Treatment Packet Transmit Operation Transmit DMA Host ConfigurationReceive and Transmit Latency Transmit Channel Teardown Transfer Node Priority Reset ConsiderationsSoftware Reset Considerations Initialization Hardware Reset ConsiderationsEnabling the EMAC/MDIO Peripheral Emac Control Module Initialization Example 5. Mdio Module Initialization Code Example 4. Emac Control Module Initialization CodeMdio Module Initialization Emac Module Initialization Emac Module Interrupt Events and Requests Interrupt SupportTransmit Packet Completion Interrupts Receive Packet Completion Interrupts Statistics Interrupt Host Error Interrupt Mdio Module Interrupt Events and Requests User Access Completion InterruptLink Change Interrupt Proper Interrupt Processing Emulation Control Power ManagementEmulation Considerations Emac Control Module Registers Emac Control Module Interrupt Control Register EwctlAcronym Register Description Bit Field Emac Control Module Interrupt Timer Count Register Ewinttcnt Mdio Version Register Version Field Descriptions Mdio Version Register VersionManagement Data Input/Output Mdio Registers Mdio Control Register Control Field Descriptions Mdio Control Register Control PHY Link Status Register Link PHY Acknowledge Status Register AlivePHY Acknowledge Status Register Alive Field Descriptions PHY Link Status Register Link Field Descriptions No Mdio link change event Will clear the event and writing a 0 has no effect No Mdio user command complete event USERINTMASKED0 and USERINTMASKED1 correspond to USERACCESS0 WS-0 Userintmaskclear Mdio User Access Register 0 USERACCESS0 Field Descriptions Mdio User Access Register 0 USERACCESS0 Linksel Linkintenb Mdio User PHY Select Register 0 USERPHYSEL0Phyadrmon Bit Field Value Description Mdio User Access Register 1 USERACCESS1 Field Descriptions Mdio User Access Register 1 USERACCESS1 Mdio User PHY Select Register 1 USERPHYSEL1 Mdio User PHY Select Register 1 USERPHYSEL1 Ethernet Media Access Controller Emac Registers Offset Acronym Register Description Ethernet Media Access Controller Emac Registers Network Statistics Registers Offset Acronym Register Description Transmit Control Register Txcontrol Field Descriptions Transmit Identification and Version Register TxidverTransmit Control Register Txcontrol Txtdnch Transmit Teardown Register TxteardownTransmit Teardown Register Txteardown Field Descriptions Receive Control Register Rxcontrol Field Descriptions Receive Identification and Version Register RxidverReceive Control Register Rxcontrol Rxtdnch Receive Teardown Register RxteardownReceive Teardown Register Rxteardown Field Descriptions TX7PEND Transmit Interrupt Status Unmasked Register Txintstatraw Transmit Interrupt Status Masked Register Txintstatmasked Transmit Interrupt Status Masked Register Txintstatmasked TX7MASK Transmit Interrupt Mask Set Register Txintmaskset Transmit Interrupt Mask Clear Register Txintmaskclear Transmit Interrupt Mask Clear Register Txintmaskclear MAC Input Vector Register Macinvector Field Descriptions MAC Input Vector Register MacinvectorUserint Linkint Hostpend Statpend Rxpend Txpend RX7PEND Receive Interrupt Status Unmasked Register Rxintstatraw Receive Interrupt Status Masked Register Rxintstatmasked Receive Interrupt Status Masked Register Rxintstatmasked RX7MASK Receive Interrupt Mask Set Register Rxintmaskset Receive Interrupt Mask Clear Register Rxintmaskclear Receive Interrupt Mask Clear Register Rxintmaskclear Hostpend Statpend MAC Interrupt Status Unmasked Register MacintstatrawMAC Interrupt Status Masked Register Macintstatmasked MAC Interrupt Mask Clear Register Macintmaskclear MAC Interrupt Mask Set Register MacintmasksetHostmask Statmask Hostmask Rxcmfen Rxpasscrc Rxqosen RxnochainRxcsfen Rxcefen Rxcafen Rxpromch Frames containing errors are filtered Receive multicast channel select RXCH7EN Receive Unicast Enable Set Register Rxunicastset Receive Unicast Clear Register Rxunicastclear Receive Unicast Clear Register Rxunicastclear Receive Maximum Length Register Rxmaxlen Field Descriptions Receive Maximum Length Register RxmaxlenReceive Buffer Offset Register Rxbufferoffset Reserved RX nFLOWTHRESH FFh Rxfilterthresh Receive Channel 0-7 Free Buffer Count Register RXnFREEBUFFER MAC Control Register Maccontrol Field Descriptions MAC Control Register Maccontrol Loopback Sent. Full-duplex mode no outgoing pause frames are sent MAC Status Register Macstatus Field Descriptions MAC Status Register Macstatus Bit Field Value Description MAC Status Register Macstatus Field Descriptions Fifo Control Register Fifocontrol Emulation Control Register EmcontrolEmulation Control Register Emcontrol Field Descriptions Fifo Control Register Fifocontrol Field Descriptions Soft Reset Register Softreset MAC Configuration Register MacconfigMAC Configuration Register Macconfig Field Descriptions Soft Reset Register Softreset Field Descriptions MAC Source Address High Bytes Register Macsrcaddrhi MAC Source Address Low Bytes Register Macsrcaddrlo MAC Hash Address Register 2 MACHASH2 MAC Hash Address Register 1 MACHASH1MAC Hash Address Register 1 MACHASH1 Field Descriptions MAC Hash Address Register 2 MACHASH2 Field Descriptions Back Off Test Register Bofftest Field Descriptions Back Off Test Register BofftestTransmit Pacing Algorithm Test Register Tpacetest Transmit Pause Timer Register Txpause Receive Pause Timer Register RxpauseReceive Pause Timer Register Rxpause Field Descriptions Transmit Pause Timer Register Txpause Field Descriptions MAC Address Low Bytes Register Macaddrlo Field Descriptions MAC Address Low Bytes Register MacaddrloMAC Address High Bytes Register Macaddrhi Macindex MAC Index Register MacindexMAC Index Register Macindex Field Descriptions TX nHDP Receive Channel 0-7 Completion Pointer Register RXnCP Transmit Channel 0-7 Completion Pointer Register TXnCP Good Receive Frames Register Rxgoodframes Network Statistics RegistersBroadcast Receive Frames Register Rxbcastframes Multicast Receive Frames Register Rxmcastframes Receive Alignment/Code Errors Register Rxaligncodeerrors Receive CRC Errors Register RxcrcerrorsPause Receive Frames Register Rxpauseframes Receive Oversized Frames Register Rxoversized Receive Undersized Frames Register Rxundersized Receive Jabber Frames Register RxjabberReceive Frame Fragments Register Rxfragments Filtered Receive Frames Register Rxfiltered Good Transmit Frames Register Txgoodframes Receive QOS Filtered Frames Register RxqosfilteredReceive Octet Frames Register Rxoctets Multicast Transmit Frames Register Txmcastframes Broadcast Transmit Frames Register TxbcastframesPause Transmit Frames Register Txpauseframes Deferred Transmit Frames Register Txdeferred Transmit Single Collision Frames Register Txsinglecoll Transmit Underrun Error Register TxunderrunTransmit Multiple Collision Frames Register Txmulticoll Transmit Late Collision Frames Register Txlatecoll Transmit and Receive 64 Octet Frames Register FRAME64 Transmit Carrier Sense Errors Register TxcarriersenseTransmit Octet Frames Register Txoctets Network Octet Frames Register Netoctets Receive DMA Overruns Register Rxdmaoverruns Appendix a Glossary Term Definition Table A-1. Physical Layer Definitions Reference Additions/Modifications/Deletions Table B-1. Document Revision History DSP Products Applications