SOP EOP Owner EOQ Tdown Pass | Texas Instruments TMS320C645x DSP

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EMAC Functional Architecture

2.5.4Transmit Buffer Descriptor Format

A transmit (TX) buffer descriptor (Figure 9) is a contiguous block of four 32-bit data words aligned on a 32-bit boundary that describes a packet or a packet fragment.

Example 1 shows the transmit buffer descriptor described by a C structure.

					Figure 9. Transmit Descriptor Format
(a) Word 0
31								0
						Next Descriptor Pointer
(b) Word 1
31								0
						Buffer Pointer
(c) Word 2
31						16	15	0
			Buffer Offset					Buffer Length
(d) Word 3
31	30	29	28	27	26	25		16
SOP	EOP	OWNER	EOQ	TDOWN	PASS			Reserved
				CMPLT	CRC
15								0
						Packet Length

Example 1. Transmit Descriptor in C Structure Format

/*

//EMAC Descriptor

//The following is the format of a single buffer descriptor

//on the EMAC.

*/
typedef struct _EMAC_Desc {
struct _EMAC_Desc *pNext;		/* Pointer to next descriptor in chain	*/
Uint8	*pBuffer;	/* Pointer to data buffer	*/
Uint32	BufOffLen;	/* Buffer Offset(MSW) and Length(LSW)	*/
Uint32	PktFlgLen;	/* Packet Flags(MSW) and Length(LSW)	*/

} EMAC_Desc;
/* Packet Flags */
#define EMAC_DSC_FLAG_SOP	0x80000000u
#define EMAC_DSC_FLAG_EOP	0x40000000u
#define EMAC_DSC_FLAG_OWNER	0x20000000u
#define EMAC_DSC_FLAG_EOQ	0x10000000u
#define EMAC_DSC_FLAG_TDOWNCMPLT	0x08000000u
#define EMAC_DSC_FLAG_PASSCRC	0x04000000u

30	Ethernet Media Access Controller (EMAC)/Management Data Input/Output (MDIO)	SPRU975B –August 2006
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Texas Instruments TMS320C645x DSP Transmit Buffer Descriptor Format, Example 1. Transmit Descriptor in C Structure Format

Contents

Users Guide Submit Documentation Feedback Contents Receive Unicast Clear Register Rxunicastclear Appendix a Appendix B List of Figures Transmit Pacing Algorithm Test Register Tpacetest List of Tables MAC Control Register Maccontrol Field Descriptions Read This First Features Purpose of the Peripheral Functional Block Diagram Emac and Mdio Block Diagram Industry Standards Compliance Statement Rmii Clocking Clock ControlMII Clocking Gmii Clocking Memory Map Rgmii Clocking Interface Selection Pins System Level ConnectionsMedia Independent Interface MII Connections Mrxdv Emac and Mdio Signals for MII InterfaceMtxen Control Reduced Media Independent Interface Rmii Connections Mtxen Mcrsdv MrefclkMrxer Mdclk Mdio Emac and Mdio Signals for Rmii Interface Gigabit Media Independent Interface Gmii Connections Mtclk Gmtclk Emac and Mdio Signals for Gmii Interface Signal Name Description TXC Txctl Refclk RXCRxctl Mdclk Mdio Emac and Mdio Signals for Rgmii Interface TXC Ethernet Protocol Overview Ethernet Frame FormatEthernet Frame Description Multiple Access Protocol Programming Interface Packet Buffer DescriptorsBasic Descriptors Typical Descriptor Linked List Transmit and Receive Descriptor Queues Transmit and Receive Emac Interrupts SOP EOP Owner EOQ Tdown Pass Transmit Buffer Descriptor FormatExample 1. Transmit Descriptor in C Structure Format Cmplt CRC Buffer Offset Next Descriptor PointerBuffer Pointer Buffer Length End of Queue EOQ Flag End of Packet EOP FlagOwnership Owner Flag Teardown Complete Tdowncmplt Flag Receive Buffer Descriptor Format Example 2. Receive Descriptor in C Structure Format Next Descriptor Pointer Jabber Flag Oversize Flag CRC Error Crcerror Flag Code Error Codeerror FlagAlignment Error Alignerror Flag Fragment Flag Bus Arbiter Emac Control ModuleInternal Memory CPU Management Data Input/Output Mdio Module Interrupt ControlMdio Module Components Global PHY Detection and Link State Monitoring PHY Register User AccessMdio Clock Generator Active PHY Monitoring Mdio Module Operational Overview Initializing the Mdio Module Example of Mdio Register Access Code Writing Data to a PHY RegisterReading Data From a PHY Register Example 3. Mdio Register Access Macros #define PHYREGreadregadr, phyadr Receive DMA Engine Emac ModuleEmac Module Components Receive Fifo Transmit DMA Engine MAC ReceiverReceive Address Transmit Fifo Clock and Reset Logic Emac Module Operational Overview Receive Control Media Independent InterfacesData Reception Receive Inter-Frame Interval Collision-Based Receive Buffer Flow Control Ieee 802.3X Based Receive Buffer Flow Control Adaptive Performance Optimization APO Transmit ControlCRC Insertion Interpacket-Gap IPG Enforcement Transmit Flow Control Speed, Duplex, and Pause Frame Support Receive DMA Host Configuration Packet Receive OperationReceive Channel Enabling Receive Channel Addressing Hardware Receive QOS Support Host Free Buffer Tracking Receive Channel TeardownReceive Frame Classification Promiscuous Receive Mode Receive Frame Treatment Summary Receive Overrun Middle of Frame Overrun Treatment Receive and Transmit Latency Transmit DMA Host ConfigurationPacket Transmit Operation Transmit Channel Teardown Hardware Reset Considerations Reset ConsiderationsSoftware Reset Considerations Transfer Node Priority Initialization Enabling the EMAC/MDIO PeripheralEmac Control Module Initialization Example 4. Emac Control Module Initialization Code Mdio Module InitializationExample 5. Mdio Module Initialization Code Emac Module Initialization Interrupt Support Emac Module Interrupt Events and RequestsTransmit Packet Completion Interrupts Receive Packet Completion Interrupts Statistics Interrupt Mdio Module Interrupt Events and Requests Host Error InterruptUser Access Completion Interrupt Link Change Interrupt Proper Interrupt Processing Power ManagementEmulation Considerations Interrupt Multiplexing Introduction Emac Control Module Interrupt Control Register EwctlEmac Control Module Registers Ewint Tcnt Management Data Input/Output Mdio Registers Modid Revmaj Revmin Mdio Version Register VersionMdio Version Register Version Field Descriptions Modid Mdio Control Register Control Mdio Control Register Control Field Descriptions PHY Acknowledge Status Register Alive PHY Acknowledge Status Register Alive Field Descriptions PHY Link Status Register Link PHY Link Status Register Link Field Descriptions 31-2 Linkint Masked Userintraw Will clear the interrupt and writing 0 has no effect Maskset Userintmask Clear Mdio User Access Register 0 USERACCESS0 Mdio User Access Register 0 USERACCESS0 Field Descriptions Phyadrmon Mdio User PHY Select Register 0 USERPHYSEL0Linksel Linkintenb Linksel Mdio User Access Register 1 USERACCESS1 Mdio User Access Register 1 USERACCESS1 Field Descriptions Mdio User PHY Select Register 1 USERPHYSEL1 Mdio User PHY Select Register 1 USERPHYSEL1 Ethernet Media Access Controller Emac Registers RX7FREEBUFFER MacconfigSoftreset Maccontrol TX6CP RxcrcerrorsRxaligncodeerrors TX7CP Rxsofoverruns FRAME1024TUPNetoctets Rxmofoverruns Transmit Identification and Version Register Txidver Txident Txmajorver TxminorverTxident Transmit Control Register Txcontrol Transmit Control Register Txcontrol Field DescriptionsTxen Transmit Teardown Register Txteardown Transmit Teardown Register Txteardown Field DescriptionsTxtdnch Receive Identification and Version Register Rxidver Rxident Rxmajorver RxminorverRxident Receive Control Register Rxcontrol Receive Control Register Rxcontrol Field DescriptionsRxen Receive Teardown Register Rxteardown Receive Teardown Register Rxteardown Field DescriptionsRxtdnch Transmit Interrupt Status Unmasked Register Txintstatraw Transmit Interrupt Status Masked Register Txintstatmasked Transmit Interrupt Status Masked Register Txintstatmasked Transmit Interrupt Mask Set Register Txintmaskset Transmit Interrupt Mask Clear Register Txintmaskclear Transmit Interrupt Mask Clear Register Txintmaskclear MAC Input Vector Register Macinvector MAC Input Vector Register Macinvector Field Descriptions 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 MAC Interrupt Status Unmasked Register Macintstatraw Host Stat Pend MAC Interrupt Status Masked Register Macintstatmasked MAC Interrupt Status Masked Register Macintstatmasked Hostmask MAC Interrupt Mask Set Register MacintmasksetHost Stat Mask Statmask MAC Interrupt Mask Clear Register Macintmaskclear MAC Interrupt Mask Clear Register Macintmaskclear Rxcsfen Rxcefen Rxcafen Rxpasscrc Rxqosen RxnochainRxcmfen Rxpromch Rxbroaden RxbroadchRxmulten RXCH6EN RXCH5EN RXCH4EN RXCH3EN RXCH2EN RXCH1EN RXCH0EN Receive Unicast Enable Set Register RxunicastsetRxmultch RXCH7EN Receive Unicast Clear Register Rxunicastclear Receive Unicast Clear Register Rxunicastclear Receive Maximum Length Register Rxmaxlen Receive Maximum Length Register Rxmaxlen Field Descriptions Receive Buffer Offset Register Rxbufferoffset RxbufferOffset Rxfilterthresh Reserved RX nFLOW Thresh Receive Channel 0-7 Free Buffer Count Register RXnFREEBUFFER MAC Control Register Maccontrol MAC Control Register Maccontrol Field Descriptions GIG CmdidleTxptype Txpace Txerrcode MAC Status Register MacstatusMAC Status Register Macstatus Field Descriptions Txerrch Rgmiigig RxerrcodeRxerrch Rgmiifull Soft Free Emulation Control Register EmcontrolEmulation Control Register Emcontrol Field Descriptions Soft Rxfifoflowthresh Fifo Control Register FifocontrolFifo Control Register Fifocontrol Field Descriptions Txcellthresh Txcelldepth Rxcelldepth Addresstype Maccfig MAC Configuration Register MacconfigMAC Configuration Register Macconfig Field Descriptions Txcelldepth Soft Reset Register Softreset Soft Reset Register Softreset Field Descriptions MAC Source Address Low Bytes Register Macsrcaddrlo MACSRCADDR0 MACSRCADDR1MACSRCADDR0 MAC Source Address High Bytes Register Macsrcaddrhi MACSRCADDR2 MACSRCADDR3 MACSRCADDR4 MACSRCADDR5MACSRCADDR2 MAC Hash Address Register 1 MACHASH1 MAC Hash Address Register 1 MACHASH1 Field Descriptions MAC Hash Address Register 2 MACHASH2 MAC Hash Address Register 2 MACHASH2 Field Descriptions Rndnum Back Off Test Register BofftestBack Off Test Register Bofftest Field Descriptions Collcount Transmit Pacing Algorithm Test Register Tpacetest Paceval Receive Pause Timer Register Rxpause Receive Pause Timer Register Rxpause Field DescriptionsPausetimer Transmit Pause Timer Register Txpause Transmit Pause Timer Register Txpause Field Descriptions Valid Match Channel Filt MACADDR0 MACADDR1 MAC Address Low Bytes Register MacaddrloMAC Address Low Bytes Register Macaddrlo Field Descriptions Valid MAC Address High Bytes Register Macaddrhi MACADDR2 MACADDR3 MACADDR4 MACADDR5MACADDR2 MAC Index Register Macindex MAC Index Register Macindex Field Descriptions TX nHDP RX nHDP Transmit Channel 0-7 Completion Pointer Register TXnCP Transmit Channel n Completion Pointer Register TX nCP Receive Channel 0-7 Completion Pointer Register RXnCP Receive Channel n Completion Pointer Register RX nCP Good Receive Frames Register Rxgoodframes Network Statistics RegistersStatistics Register Field Descriptions Broadcast Receive Frames Register Rxbcastframes Multicast Receive Frames Register Rxmcastframes Receive CRC Errors Register RxcrcerrorsReceive Alignment/Code Errors Register Rxaligncodeerrors Pause Receive Frames Register Rxpauseframes Receive Undersized Frames Register Rxundersized Receive Oversized Frames Register RxoversizedReceive Jabber Frames Register Rxjabber Receive Frame Fragments Register Rxfragments Receive Octet Frames Register Rxoctets Filtered Receive Frames Register RxfilteredReceive QOS Filtered Frames Register Rxqosfiltered Good Transmit Frames Register Txgoodframes Pause Transmit Frames Register Txpauseframes Broadcast Transmit Frames Register TxbcastframesMulticast Transmit Frames Register Txmcastframes Deferred Transmit Frames Register Txdeferred Transmit Multiple Collision Frames Register Txmulticoll Transmit Underrun Error Register TxunderrunTransmit Single Collision Frames Register Txsinglecoll Transmit Late Collision Frames Register Txlatecoll Transmit Carrier Sense Errors Register Txcarriersense Transmit Octet Frames Register TxoctetsTransmit and Receive 64 Octet Frames Register FRAME64 Network Octet Frames Register Netoctets 144 Appendix a Glossary Table A-1. Physical Layer Definitions Term Definition Appendix B Revision History Table B-1. Document Revision History Important Notice