Freescale Semiconductor MPC860T TxBD Active Register Xdesactive, describes Rdesactive Þelds

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Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

Bits	0	1	2	3	4	5	6	7	8	9	10	11		12	13	14	15

Field				Ñ				R_DES_ACTIVE					Ñ

Reset								0000_0000_0000_0000

R/W								Read/write

Addr								0xE50

Bits	16	17	18	19	20	21	22	23	24	25	26	27		28	29	30	31

Field	0	0	0	0	0	0	0	0	0	0	0	0		0	0	0	0

Reset								0000_0000_0000_0000

R/W								Read/write

Addr								0xE52

Figure 6-11. R_DES_ACTIVE Register

Table 6-12 describes R_DES_ACTIVE Þelds.

Table 6-12. R_DES_ACTIVE Field Descriptions

Bits	Name	Description

0Ð6	Ñ	Reserved.

7	R_DES_ACTIVE	Signals the FEC that empty buffers are available. Set when this register is written,
		regardless of the value written. Cleared by the FEC whenever no additional BDs are
		ready in the RxBD ring.

8Ð31	Ñ	Reserved.

6.2.12 TxBD Active Register (X_DES_ACTIVE)

The TxBD active register, shown in Figure 6-12, is a command register that the user should write to indicate that the TxBD ring was updated (transmit buffers have been produced by the software driver with TxBD[R] set).

Whenever the register is written, X_DES_ACTIVE is set, regardless of the data written by the user. When the bit is set, the TxBD ring is polled and transmit frames (provided ECNTRL[ETHER_EN] is also set) are processed. Once a TxBD whose ownership bit is not set is polled, X_DES_ACTIVE is cleared and polling stops until the bit is set, signifying additional BDs have been placed into the TxBD ring.

X_DES_ACTIVE is cleared at reset and by clearing ECNTRL[ETHER_EN].

MOTOROLAChapter 6.Programming Model6-11

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Contents Freescale Semiconductor, Inc MPC860T Rev. D Fast Ethernet ControllerMotorola Literature Distribution Centers Contents Parallel I/O Ports Contents Paragraph Title Number Title Number IllustrationsViii MPC860T Rev. D Fast Ethernet Controller Supplement Tables Number Document Revision History Document Revision HistoryOverview Lists signiÞcant changes between revisions of this documentComparison with the MPC860 Features1 MPC860TBlock Diagram System Interface Unit SIU Embedded PowerPC Processor CoreFast Ethernet Controller SIU Interrupt ConÞguration Glueless System DesignInc FEC Signal Descriptions Signal DescriptionsName Pin Description Miitxer L1RSYNCBMiimdc RXD3MIITXD1 REJECT3MIITXD2 REJECT4Freescale Semiconductor, Inc This chapter discusses the operation of the FEC MII SignalsSignal Description FEC Signal Name Transceiver ConnectionRXD0 Serial Mode Connections to the External TransceiverFEC Frame Transmission TXD0FEC Frame Reception CAM Interface FEC Command SetEthernet Address Recognition Rcntrlprom = Hash Table AlgorithmCollision Handling Inter-Packet Gap TimeInternal and External Loopback Ethernet Error-Handling ProcedureTransmission Errors Reception ErrorsReception Errors Port D Pin Functions Chapter Parallel I/O PortsShows the port D pin assignments Enabling MII ModeSignal Function Port D RegistersCLK Sdma RegistersBits Describes Sdcr ÞeldsSdcr Field Descriptions FRZ Faid RAIDAddress Name Description Section Parameter RAMBrießy describes each enter in the FEC parameter RAM FEC Parameter RAM Memory MapRAM Perfect Match Address Low Register Addrlow Describes the Addrhigh Þelds RAM Perfect Match Address High AddrhighRAM Hash Table High Hashtablehigh Describes the Addrlow ÞeldsHashhigh RAM Hash Table Low HashtablelowDescribes Hashtablehigh Þelds Hashtablehigh Field DescriptionsDescribes Rdesstart Þelds Beginning of RxBD Ring RdesstartBeginning of TxBD Ring Xdesstart Describes Hashtablelow ÞeldsDescribes Xdesstart Þelds Receive Buffer Size Register RbuffsizeXdesstart Field Descriptions Rbuffsize Field Descriptions Spare Fecpin Etheren Reset MUXEthernet Control Register Ecntrl Describes Rbuffsize ÞeldsFecpinmux Interrupt Event IEVENT/Interrupt Mask Register ImaskDescribes Ecntrl Þelds Ecntrl Field DescriptionsHberr Ethernet Interrupt Vector Register IvecRfint to notify at the end of frame 10. IEVENT/IMASK Field DescriptionsIlevel RxBD Active Register Rdesactive11 describes Ivec Þelds 11. Ivec Field Descriptions12 describes Rdesactive Þelds TxBD Active Register Xdesactive12. Rdesactive Field Descriptions 13 describes Xdesactive Þelds MII Management Frame Register Miidata13. Xdesactive Field Descriptions 14. Miidata Field Descriptions 14 describes Miidata ÞeldsDispreamble Miispeed MII Speed Control Register Miispeed15 describes Miispeed Þelds 15. Miispeed Field Descriptions17. Rbound Field Descriptions Fifo Receive Bound Register Rbound17 describes Rbound Þelds 16. Programming Examples for Miispeed Register18. Rfstart Field Descriptions Fifo Receive Start Register RfstartTransmit Watermark Register Xwmrk 18 describes Rñfstart Þelds19 bit Þeld descriptions for Xwmrk Fifo Transmit Start Register Xfstart19. Xwmrk Field Descriptions DATABO0 DATABO1 DESCBO0 DESCBO1 FC1 FC2 FC3 DMA Function Code Register Funcode20 describes Xfstart Þelds 20. Xfstart Field DescriptionsDescbo Receive Control Register Rcntrl21 describes Funcode Þelds 21. Funcode Field DescriptionsBcrej Receive Hash Register Rhash22 describes Rcntrl Þelds 22. Rcntrl Field Descriptions23. Rhash Field Descriptions Transmit Control Register Xcntrl22 describes Rhash Þelds 24 describes Xcntrl Þelds25. Hardware Initialization User Initialization before Setting EcntrletherenInitialization Sequence Hardware InitializationStep Description 27. User Initialization before Setting EcntrletherenDescriptor Controller Initialization User Initialization after Asserting EcntrletherenStep 27. User Initialization after Setting EcntrletherenBuffer Descriptors BDs Ethernet Receive Buffer Descriptor RxBDRO1 RxBD format is shown in Table27. Receive Buffer Descriptor RxBD Field Description RO1 RO2 Data LengthTO1 TO2 DEF CSL Ethernet Transmit Buffer Descriptor TxBD29 describes TxBD Þelds 29. Transmit Buffer Descriptor TxBD Field DescriptionsData Xcntrlhbc =Freescale Semiconductor, Inc Electrical SpeciÞcations DC Electrical CharacteristicsAC Electrical Characteristics MII Receive Signal Timing RXD30, RXDV, RXER, RxclkNum Characteristic Min Max Unit MII Transmit Signal Timing TXD30, TXEN, TXER, TxclkMII Receive Signal Timing MII Transmit Signal TimingCRS, COL MII Async Inputs Signal Timing CRS, COLMII Async Inputs Signal Timing Txen TxerMII Serial Management Channel Timing Shows the MII serial management channel timing diagramMPC860T Pin Assignments Following pins are marked as spare onFreescale Semiconductor, Inc Freescale Semiconductor, Inc For More Information On This Product