Freescale Semiconductor MPC860T MII Speed Control Register Miispeed, describes Miispeed Þelds

Page 46

Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

completes. At this time the contents of MII_DATA match the original value written except for the DATA Þeld, whose contents have been replaced by the value read from the PHY register.

Writing to MII_DATA during frame generation alters the frame contents. Software should use the MII_DATAIO_COMPL interrupt to avoid writing to the MII_DATA register during frame generation.

6.2.14 MII Speed Control Register (MII_SPEED)

The MII_SPEED register, shown in Figure 6-14, provides control of the MII clock (MDC pin) frequency and allows the MII management frame preamble to be dropped. MII_SPEED is written by the user.

Bits

0

1

2

3

 

4

5

6

7

8

9

10

11

12

13

14

15

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Field

 

 

 

 

 

 

 

 

 

Ñ

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset

 

 

 

 

 

 

 

 

0000_0000_0000_0000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R/W

 

 

 

 

 

 

 

 

 

Read/write

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Addr

 

 

 

 

 

 

 

 

 

0xE84

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bits

16

17

18

19

 

20

21

22

23

24

25

26

27

28

29

30

31

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Field

 

 

 

 

Ñ

 

 

 

DIS_PREAMBLE

 

 

MII_SPEED

 

 

Ñ

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset

 

 

 

 

 

 

 

 

0000_0000_0000_0000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R/W

 

 

 

 

 

 

 

 

 

Read/write

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Addr

 

 

 

 

 

 

 

 

 

0xE86

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 6-14. MII_SPEED Register

Table 6-15 describes MII_SPEED Þelds.

 

 

Table 6-15. MII_SPEED Field Descriptions

 

 

 

Bits

Name

Description

 

 

 

0Ð23

Ñ

Reserved. Should be written to zero by the host processor.

 

 

 

24

DIS_PREAMBLE

Discard preamble. The MII standard allows the preamble to be dropped if the attached

 

 

PHY devices does not require it.

 

 

0 Preamble is not discarded.

 

 

1 Causes the preamble (32 1s) not to be prepended to the MII management frame.

 

 

 

25Ð30

MII_SPEED

MII_SPEED controls the frequency of the MII management interface clock (MDC)

 

 

relative to system clock. Clearing MII_SPEED, turns off the MDC and leaves it in

 

 

low-voltage state. Any non-zero value generates an MDC frequency of

 

 

1/(MII_SPEED*2) of the system clock frequency.

 

 

 

31

Ñ

Reserved. Should be written to zero by the host processor.

 

 

 

The MII_SPEED Þeld must be programmed with a value to provide an MDC frequency of less than or equal to 2.5 MHz to comply with the IEEE MII speciÞcation. MII_SPEED must

6-14MPC860T (Rev. D) Fast Ethernet Controller Supplement MOTOROLA

PRELIMINARYÑSUBJECTFor ore nformationTO CHANGEOn ThisWITHOUTProduct,NOTICE

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Contents MPC860T Rev. D Fast Ethernet Controller Freescale Semiconductor, IncMotorola Literature Distribution Centers Contents Parallel I/O Ports Contents Paragraph Title Number Illustrations Title NumberViii MPC860T Rev. D Fast Ethernet Controller Supplement Tables Number Lists signiÞcant changes between revisions of this document Document Revision HistoryOverview Document Revision HistoryFeatures Comparison with the MPC8601 MPC860TBlock Diagram System Interface Unit SIU Embedded PowerPC Processor CoreFast Ethernet Controller Glueless System Design SIU Interrupt ConÞgurationInc FEC Signal Descriptions Signal DescriptionsName Pin Description RXD3 L1RSYNCBMiimdc MiitxerREJECT4 REJECT3MIITXD2 MIITXD1Freescale Semiconductor, Inc Transceiver Connection MII SignalsSignal Description FEC Signal Name This chapter discusses the operation of the FECTXD0 Serial Mode Connections to the External TransceiverFEC Frame Transmission RXD0FEC Frame Reception CAM Interface FEC Command SetEthernet Address Recognition Hash Table Algorithm Rcntrlprom =Inter-Packet Gap Time Collision HandlingReception Errors Ethernet Error-Handling ProcedureTransmission Errors Internal and External LoopbackReception Errors Chapter Parallel I/O Ports Port D Pin FunctionsPort D Registers Enabling MII ModeSignal Function Shows the port D pin assignmentsSdma Registers CLKFRZ Faid RAID Describes Sdcr ÞeldsSdcr Field Descriptions BitsFEC Parameter RAM Memory Map Parameter RAMBrießy describes each enter in the FEC parameter RAM Address Name Description SectionRAM Perfect Match Address Low Register Addrlow Describes the Addrlow Þelds RAM Perfect Match Address High AddrhighRAM Hash Table High Hashtablehigh Describes the Addrhigh ÞeldsHashtablehigh Field Descriptions RAM Hash Table Low HashtablelowDescribes Hashtablehigh Þelds HashhighDescribes Hashtablelow Þelds Beginning of RxBD Ring RdesstartBeginning of TxBD Ring Xdesstart Describes Rdesstart ÞeldsDescribes Xdesstart Þelds Receive Buffer Size Register RbuffsizeXdesstart Field Descriptions Describes Rbuffsize Þelds Spare Fecpin Etheren Reset MUXEthernet Control Register Ecntrl Rbuffsize Field DescriptionsEcntrl Field Descriptions Interrupt Event IEVENT/Interrupt Mask Register ImaskDescribes Ecntrl Þelds Fecpinmux10. IEVENT/IMASK Field Descriptions Ethernet Interrupt Vector Register IvecRfint to notify at the end of frame Hberr11. Ivec Field Descriptions RxBD Active Register Rdesactive11 describes Ivec Þelds Ilevel12 describes Rdesactive Þelds TxBD Active Register Xdesactive12. Rdesactive Field Descriptions 13 describes Xdesactive Þelds MII Management Frame Register Miidata13. Xdesactive Field Descriptions 14 describes Miidata Þelds 14. Miidata Field Descriptions15. Miispeed Field Descriptions MII Speed Control Register Miispeed15 describes Miispeed Þelds Dispreamble Miispeed16. Programming Examples for Miispeed Register Fifo Receive Bound Register Rbound17 describes Rbound Þelds 17. Rbound Field Descriptions18 describes Rñfstart Þelds Fifo Receive Start Register RfstartTransmit Watermark Register Xwmrk 18. Rfstart Field Descriptions19 bit Þeld descriptions for Xwmrk Fifo Transmit Start Register Xfstart19. Xwmrk Field Descriptions 20. Xfstart Field Descriptions DMA Function Code Register Funcode20 describes Xfstart Þelds DATABO0 DATABO1 DESCBO0 DESCBO1 FC1 FC2 FC321. Funcode Field Descriptions Receive Control Register Rcntrl21 describes Funcode Þelds Descbo22. Rcntrl Field Descriptions Receive Hash Register Rhash22 describes Rcntrl Þelds Bcrej24 describes Xcntrl Þelds Transmit Control Register Xcntrl22 describes Rhash Þelds 23. Rhash Field DescriptionsHardware Initialization User Initialization before Setting EcntrletherenInitialization Sequence 25. Hardware InitializationUser Initialization after Asserting Ecntrletheren 27. User Initialization before Setting EcntrletherenDescriptor Controller Initialization Step DescriptionEthernet Receive Buffer Descriptor RxBD 27. User Initialization after Setting EcntrletherenBuffer Descriptors BDs StepRO1 RO2 Data Length RxBD format is shown in Table27. Receive Buffer Descriptor RxBD Field Description RO129. Transmit Buffer Descriptor TxBD Field Descriptions Ethernet Transmit Buffer Descriptor TxBD29 describes TxBD Þelds TO1 TO2 DEF CSLXcntrlhbc = DataFreescale Semiconductor, Inc MII Receive Signal Timing RXD30, RXDV, RXER, Rxclk DC Electrical CharacteristicsAC Electrical Characteristics Electrical SpeciÞcationsMII Transmit Signal Timing MII Transmit Signal Timing TXD30, TXEN, TXER, TxclkMII Receive Signal Timing Num Characteristic Min Max UnitTxen Txer MII Async Inputs Signal Timing CRS, COLMII Async Inputs Signal Timing CRS, COLShows the MII serial management channel timing diagram MII Serial Management Channel TimingFollowing pins are marked as spare on MPC860T Pin AssignmentsFreescale Semiconductor, Inc Freescale Semiconductor, Inc For More Information On This Product
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