Emac Control Module, Bus Arbiter | Texas Instruments TMS320C674X

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Architecture

2.6EMAC Control Module

The EMAC control module (Figure 9) interfaces the EMAC and MDIO modules to the rest of the system, and also provides a local memory space to hold EMAC packet buffer descriptors. Local memory is used to help avoid contention with device memory spaces. Other functions include the bus arbiter, and interrupt logic control.

Figure 9. EMAC Control Module Block Diagram

Transmit and Receive DMA Controllers

Configuration bus

EMAC interrupts

MDIO interrupts

Arbiter and			CPU
bus switches			CPU
bus switches

8K byte

descriptor memory

Configuration

registers

					Interrupts
	Interrupt				Interrupts
	logic				to CPU

2.6.1Internal Memory

The EMAC control module includes 8K bytes of internal memory (CPPI buffer descriptor memory). The internal memory block is essential for allowing the EMAC to operate more independently of the CPU. It also prevents memory underflow conditions when the EMAC issues read or write requests to descriptor memory. (Memory accesses to read or write the actual Ethernet packet data are protected by the EMAC's internal FIFOs).

A descriptor is a 16-byte memory structure that holds information about a single Ethernet packet buffer, which may contain a full or partial Ethernet packet. Thus with the 8K memory block provided for descriptor storage, the EMAC module can send and received up to a combined 512 packets before it needs to be serviced by application or driver software.

2.6.2Bus Arbiter

The EMAC control module bus arbiter operates transparently to the rest of the system. It is used:

•To arbitrate between the CPU and EMAC buses for access to internal descriptor memory.

•To arbitrate between internal EMAC buses for access to system memory.

SPRUFL5B –April 2011	EMAC/MDIO Module	29
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Texas Instruments TMS320C674X manual Emac Control Module, Internal Memory, Bus Arbiter, Cpu

Contents

Users Guide Submit Documentation Feedback C0MISCEN-C2MISCEN C0TXIMAX-C2TXIMAX Appendix B Appendix a List of Figures MAC Interrupt Mask Clear Register Macintmaskclear List of Tables MAC Control Register Maccontrol Field Descriptions Read This First Related Documentation From Texas Instruments 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 for MII Interface Reduced Media Independent Interface Rmii Connections Emac and Mdio Signals for Rmii Interface Ethernet Frame Format Ethernet Protocol OverviewEthernet Frame Description Field Bytes Description Programming Interface Ethernet’s Multiple Access ProtocolPacket Buffer Descriptors Word Field Field Description Basic Descriptor Description Transmit and Receive Descriptor Queues Transmit Buffer Descriptor Format 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 Example 2. Receive Buffer Descriptor in C Structure Format Buffer Length Alignment Error Alignerror Flag Code Error Codeerror FlagCRC Error Crcerror Flag Jabber Flag Internal Memory Emac Control ModuleBus Arbiter CPU 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 MAC InterfaceReceive 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 Transmit Channel Teardown Transmit DMA Host ConfigurationPacket Transmit Operation Transfer Node Priority Receive and Transmit Latency Hardware Reset Considerations Reset ConsiderationsSoftware Reset Considerations Enabling the EMAC/MDIO Peripheral InitializationEmac Control Module Initialization Mdio Module Initialization Macintmaskset Emac Module Initialization Emac Module Interrupt Events and Requests Interrupt SupportTransmit Packet Completion Interrupts Receive Packet Completion Interrupts Statistics Interrupt Host Error Interrupt Link Change Interrupt Receive Threshold InterruptsMdio Module Interrupt Events and Requests Interrupt Multiplexing User Access Completion InterruptProper Interrupt Processing Emulation Control Power ManagementEmulation Considerations Acronym Register Description Emac Control Module Registers Bit Field Value Description Emac Control Module Revision ID Register RevidOffset Acronym Register Description Reset Emac Control Module Software Reset Register Softreset C2TXPACEEN Emac Control Module Interrupt Control Register IntcontrolIntprescale Bit Field RXCH7EN TXCH7EN Statpenden Statpenden Hostpenden LINKINT0EN USERINT0EN RXCH6THRESHSTAT RXCH7THRESHSTATRXCH5THRESHSTAT RXCH4THRESHSTAT RXCH7STAT TXCH7STAT Hostpendstat StatpendstatLINKINT0STAT USERINT0STAT Allowemacinterrupts Rximax Tximax Mdio Revision ID Register Revid Field Descriptions Mdio Revision ID Register RevidManagement 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 USERPHY1 USERPHY1 USERPHY0 Writing a 0 has no effect USERACCESS1 USERACCESS0 Effect W1S-0 Userintmaskclear Mdio User Command Complete Interrupt Mask Clear Register Mdio User Access Register 0 USERACCESS0 Field Descriptions Mdio User Access Register 0 USERACCESS0 Linksel Linkintenb Mdio User PHY Select Register 0 USERPHYSEL0Phyadrmon Linksel 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 Macstatus MacconfigEmcontrol Fifocontrol Network Statistics Registers Transmit Control Register Txcontrol Transmit Revision ID Register TxrevidTransmit Revision ID Register Txrevid Field Descriptions Transmit Control Register Txcontrol Field Descriptions Txtdnch Transmit Teardown Register TxteardownTransmit Teardown Register Txteardown Field Descriptions Receive Control Register Rxcontrol Receive Revision ID Register RxrevidReceive Revision ID Register Rxrevid Field Descriptions Receive Control Register Rxcontrol Field Descriptions 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 MacinvectorStatpend RX0THRESHPEND Intvect MAC End Of Interrupt Vector Register Maceoivector Receive Interrupt Status Unmasked Register Rxintstatraw Receive Interrupt Status Masked Register Rxintstatmasked Receive Interrupt Status Masked Register Rxintstatmasked 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 Receive Unicast Enable Set Register Rxunicastset 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 Rxfilterthresh Receive Channel Flow Control Threshold Registers Receive Channel n Free Buffer Count Register RXnFREEBUFFER MAC Control Register Maccontrol Field Descriptions MAC Control Register Maccontrol Rxbufferflowen TxflowenLoopback Fullduplex MAC Status Register Macstatus Field Descriptions MAC Status Register Macstatus Rxqosact 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 MacaddrloValid Matchfilt Channel MACADDR0 MACADDR1 Valid MAC Index Register Macindex MAC Address High Bytes Register MacaddrhiMAC Index Register Macindex Field Descriptions MACADDR2 MACADDR3 MACADDR4 MACADDR5 TXnHDP Receive Channel Completion Pointer Registers RX0CP-RX7CP Transmit Channel Completion Pointer Registers TX0CP-TX7CP Good Receive Frames Register Rxgoodframes Network Statistics RegistersBroadcast Receive Frames Register Rxbcastframes Multicast Receive Frames Register Rxmcastframes Pause Receive Frames Register Rxpauseframes Receive CRC Errors Register RxcrcerrorsReceive Alignment/Code Errors Register Rxaligncodeerrors Receive Jabber Frames Register Rxjabber Receive Oversized Frames Register RxoversizedReceive Undersized Frames Register Rxundersized Receive Frame Fragments Register Rxfragments 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 Physical Layer Definitions Reference Additions/Modifications/Deletions Document Revision History DSP Products ApplicationsRfid TI E2E Community Home