Lantronix DSTni-EX manual RX Message Registers, 2. RX Message Routing

Page 74

RX Message Registers

A 4-message-deep FIFO stores the incoming messages. Status flags indicate how many messages are stored. Additional flags determine from which acceptance filter the actual message is coming from.

Figure 5-2. RX Message Routing

uP Bus	0	1	2	3

	RxMessage	RxMessage	RxMessage	RxMessage
	RxMessage	RxMessage	RxMessage	RxMessage

To read received messages:

1.Wait for rx_msg interrupt.

2.MessageReadLoop:

MESSAGE FILTERS

CAN Module

CAN BUS

read message

acknowledge ‘ message read’ by writing a ‘ 1’ to MsgAv register read MsgAv; reading a ‘ 1’ means a new message is available IF MsgAv=1 THEN jump to MessageReadLoop

3.Acknowledge rx_msg interrupt by writing a ‘ 1’ to this register location.

Image 74

Contents DSTni-EX User Guide Section FivePage Technical Support Copyright & TrademarkLantronix Master DistributorWarranty 2 SPI Controller Contents1 About This User Guide 3 I2C ControllerList of Tables 5 CAN ControllersTable 3-17. Clock Control Register List of Figures 1 About This User Guide Navigating Online Intended AudienceConventions Notes Notes are information requiring attentionOrganization SPI Background 2 SPI ControllerTheory of Operation DSTni SPI ControllerSPI Controller Register Summary Table 2-1. SPI Controller Register SummaryRESET SPI Controller Register DefinitionsSPIDATA Register Table 2-2. SPIDATA RegisterPhase Select CTL RegisterInterrupt Request Enable Wire-OTable 2-7. SPISTAT Register Definitions SPISTAT RegisterTable 2-6. SPISTAT Register Interrupt RequestSelectO Signal SPISSEL RegisterTable 2-10. BCNT Bit Settings Table 2-8. SPISSEL RegisterTable 2-11. DVDCNTRLO Register DVDCNTRLO RegisterDVDCNTRHI Table 2-12. DVDCNTRLO Register DefinitionsFeatures 3 I2C ControllerFigure 3-1. DSTni I2C Controller Block Diagram Block DiagramI2C Background Master Transmit Mode I2C ControllerOperating Modes I2C State Table 3-1. Master Transmit Status CodesCode Microprocessor ResponseServicing the Interrupt Table 3-2. Codes After Servicing Interrupts Master TransmitAll Bytes Transmit Completely Transmitting Each Data ByteTable 3-3. Status Codes After Each Data Byte Transmits Master Receive ModeTable 3-4. Master Receive Status Codes Table 3-5. Codes After Servicing Interrupt Master Receive Slave Transmit Mode Receiving Each Data ByteTable 3-6. Codes After Receiving Each Data Byte Slave Receive Mode Clock Synchronization Bus Clock ConsiderationsBus Clock Speed Bus ArbitrationResetting the I2C Controller Programmer’s ReferenceI2C Controller Register Summary Table 3-7. I 2C Controller Register SummaryGeneral Call Address Enable I2C Controller Register DefinitionsSlave Address Register Table 3-8. Slave Address RegisterData Register Table 3-10. Data RegisterTable 3-13. Control Register Definitions Control RegisterTable 3-12. Control Register Extended Slave AddressStatus Register Table 3-14. Status RegisterStatus Code Table 3-15. Status Register DefinitionsTable 3-16. Status Codes Table 3-18. Clock Control Register Definitions Clock Control RegisterTable 3-17. Clock Control Register Table 3-21. Software Reset Register Software Reset RegisterExtended Slave Address Register Table 3-22. Software Reset Register Definitions4 USB Controller USB Core USB BackgroundUSB Interrupt Serial Interface EngineMicroprocessor Interface USB Hardware/Software InterfaceDigital Phase Lock Loop Logic Buffer Descriptor TableFigure 4-1. Buffer Descriptor Table Rx vs. Tx as a Target Device or HostTable 4-2. 16-Bit USB Address Table 4-1. USB Data DirectionAddressing BDT Entries Table 4-3. 16-Bit USB Address DefinitionsMicroprocessor Determines… Table 4-4. BDT Data Used by USB Controller and MicroprocessorUSB Controller Determines… Table 4-5. USB Buffer Descriptor FormatDATA0/1 Transmit or Receive Table 4-6. USB Buffer Descriptor Format DefinitionsBD Owner USB OwnershipUSB Transaction Figure 4-2. USB Token TransactionDedicated to host mode USB Register SummaryTable 4-7. USB Register Summary Table 4-8. Interrupt Status Register USB Register DefinitionsInterrupt Status Register Table 4-9. 16- Interrupt Status Register DefinitionsError Condition Enable/Disable USBRST InterruptSleep Timer USB ResetTable 4-11. 16- Error Interrupt Status Register Definitions Error RegisterTable 4-10. Error Interrupt Status Register CRC16 Failure Error interrupt with two functionsData Field Received Not 8 Bits PID check field failedTable 4-12. Status Register Live USB Differential Receiver JSTATE SignalLive USB Single Ended Zero Signal Table 4-13. Status Register DefinitionsResume Signaling USB Reset SignalHost Mode Enable valid for host mode only BDT PDD ResetTable 4-15. 16- Address Register Definitions Address RegisterTable 4-14. Address Register Table 4-17. Frame Number Register Definitions Frame Number RegistersTable 4-16. Frame Number Register Frame NumberToken Register Table 4-19. Token Register Definitions Endpoint for Token CommandTable 4-18. Token Register Table 4-20. Valid PID TokensTable 4-21. Endpoint Control Registers Endpoint Control RegistersEndpoint Enable Table 4-22. Endpoint Control Register DefinitionsHost Mode Operation Table 4-23. Endpoint Control Register DefinitionsSample Host Mode Operations Figure 3. Enable Host Mode and Configure a Target DeviceFigure 4. Full-Speed Bulk Data Transfers to a Target Device USB Pull-up/Pull-down Resistors Figure 4-5. Pull-up/Pull-down USBHOST Mode Enable USB Interface SignalsUSB Output Enable Clock CLK5 CAN Controllers Data Exchanges and Communication Arbitration and Error CheckingCANBUS Background CANBUS Speed and Length Table 5-1. Bit Rates for Different Cable LengthsHex Offset CAN Register SummariesRegister Summary RegisterHex Offset Detailed CAN Register Map Table 5-4. Detailed CAN Register MapAcceptance Filter Enable Register Hex OffsetRegister Figure 5-1. TX Message Routing CAN Register DefinitionsTX Message Registers Sending a MessageTable 5-6. TxMessage0ID12 Tx Message RegistersTable 5-5. TxMessage0ID28 Table 5-7. TxMessage0DataMessage Identifier for Both Standard and Extended Messages Table 5-12. TxMessage0Ctrl FlagsTable 5-13. TxMessage0 Register Definitions Message DataRX Message Registers Figure 5-2. RX Message RoutingTable 5-15. Rx Message ID28 Register Definitions Rx Message RegistersTable 5-14. RxMessageID28 Table 5-16. RxMessageID12Table 5-22. Rx Message Data Table 5-20. Rx Message DataTable 5-21. Rx Message Data 39 Register Definitions Table 5-23. Rx Message Data 23 Register DefinitionsTable 5-28. Rx Message Msg Flags Table 5-26. RxMessage RTRTable 5-27. Rx Message RTR Register Definitions Table 5-29. Rx Message Msg Flags Register DefinitionsTable 5-31. Tx\Rx Error Count Register Definitions Error Count and Status RegistersTable 5-30. Tx/Rx Error Count Table 5-32. Error Statusrxlevel10 Table 5-34. Tx/Rx Message Level RegisterTable 5-35. Tx/Rx Message Level Register Definitions txlevel10CRC Error Interrupt FlagsNote The reset value of this register’s bits is indeterminate Format ErrorTable 5-39. Interrupt Enable Register Definitions Interrupt Enable RegistersTable 5-38. Interrupt Enable Registers Bus Off State − int2n group error interruptsTable 5-41. Interrupt Enable Register Definitions CAN Operating ModeTable 5-40. Interrupt Enable Registers Overload Condition − int3n group diagnostic interruptsFigure 5-3. CAN Operating Mode CAN Configuration RegistersConfiguration Bit Rate Table 5-42. Bit Rate Divisor RegisterOverwrite Last Message Table 5-44. Configuration RegisterTable 5-45. Configuration Register Definitions Cfgsjwtseg2 + Bit Timetseg1 + time quanta TQTable 5-47. Acceptance Filter Enable Register Definitions Acceptance Filter and Acceptance Code MaskTable 5-46. Acceptance Filter Enable Register Table 5-48. Acceptance Mask 0 RegisterTable 5-52. Acceptance Mask Register Data Table 5-50. Acceptance Mask Register IDTable 5-51. Acceptance Mask Register ID12 Definitions D5556Table 5-56. Acceptance Mask Register ID12 Table 5-54. Acceptance Code RegisterTable 5-55. Acceptance Code Register Definitions Table 5-57. Acceptance Mask Register ID12 DefinitionsTable 5-60. Arbitration Lost Capture Register CANbus AnalysisArbitration Lost Capture Register Table 5-61. Arbitration Lost Capture Register DefinitionsTable 5-63. Error Capture Register Definitions Error Capture RegisterTable 5-62. Error Capture Register ErrorcodeTable 5-64. Frame Reference Register Table 5-65. Error Capture Register DefinitionsFrame Reference Register Stuff Bit InsertedFigure 5-6. CAN Connector CAN Bus InterfaceInterface Connections Figure 5-5. CAN Bus InterfaceGNDCAN Figure 5-7. Power for CAN+5CAN +24VFigure 5-8. CAN Transceiver and Isolation Circuits 0.01uf