Lantronix DSTni-EX manual 6. Codes After Receiving Each Data Byte, Slave Transmit Mode

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Receiving Each Data Byte

After receiving each data byte, the IFLG is set and one of three status codes in Table 3-6is in the Status register.

When all bytes are received, set the STP bit by writing a 1 to it in the Control register. The I2C controller:

Transmits a STOP condition Clears the STP bit Returns to the idle state

	Table 3-6. Codes After Receiving Each Data Byte

Code	I2C State		Microprocessor Response	Next I2C Action
50h	Data byte received,		Read DATA, clear IFLG, AAK=0	Receive data byte, transmit not ACK
	ACK transmitted		OR
			OR
			Read DATA, clear IFLG, AAK=1	Receive data byte, transmit ACK
58h	Data byte received, Not		Read DATA, set STA, clear IFLG	Transmit repeated START
	ACK transmitted		OR
			OR
			Read DATA, set STP, clear IFLG	Transmit STOP
			OR
			Read DATA, set STA & STP, clear	Transmit STOP then START
			IFLG
38h	Arbitration lost in not		Clear IFLG	Return to idle
	ACK bit		OR
			OR
			Set STA, clear IFLG	Transmit START when bus free

Slave Transmit Mode

In the slave transmit mode, a number of bytes are transmitted to a master receiver.

The I2C controller enters slave transmit mode when it receives its own slave address and a read bit after a START condition. The I2C controller then transmits an acknowledge bit and sets the IFLG bit in the Control register. The Status register contains the status code A8h.

Note: If the I2C controller has an extended slave address (signified by F0h - F7h in the Slave Address register), it transmits an acknowledge after receiving the first address byte, but does not generate an interrupt; the IFLG is not set and the status does not change. Only after receiving the second address byte does The I2C controller generate an interrupt and set the IFLG bit and status code as described above.

The I2C controller can also enter slave transmit mode directly from a master mode if arbitration is lost in master mode during address transmission, and both the slave address and read bit are received. The status code in the Status register is B0h.

After the I2C controller enters slave transmit mode:

1.The Data register loads the data byte to be transmitted, then IFLG clears.

2.The I2C controller transmits the byte.

3.The I2C controller receives or does not receive an acknowledge. If the I2C controller receives an acknowledge:

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Contents Section Five DSTni-EX User GuidePage Master Distributor Copyright & TrademarkLantronix Technical SupportWarranty 3 I2C Controller Contents1 About This User Guide 2 SPI Controller5 CAN Controllers List of TablesTable 3-17. Clock Control Register List of Figures 1 About This User Guide Notes Notes are information requiring attention Intended AudienceConventions Navigating OnlineOrganization DSTni SPI Controller 2 SPI ControllerTheory of Operation SPI BackgroundTable 2-1. SPI Controller Register Summary SPI Controller Register SummaryTable 2-2. SPIDATA Register SPI Controller Register DefinitionsSPIDATA Register RESETWire-O CTL RegisterInterrupt Request Enable Phase SelectInterrupt Request SPISTAT RegisterTable 2-6. SPISTAT Register Table 2-7. SPISTAT Register DefinitionsTable 2-8. SPISSEL Register SPISSEL RegisterTable 2-10. BCNT Bit Settings SelectO SignalTable 2-12. DVDCNTRLO Register Definitions DVDCNTRLO RegisterDVDCNTRHI Table 2-11. DVDCNTRLO Register3 I2C Controller FeaturesBlock Diagram I2C BackgroundFigure 3-1. DSTni I2C Controller Block Diagram I2C Controller Operating ModesMaster Transmit Mode Microprocessor Response Table 3-1. Master Transmit Status CodesCode I2C StateTable 3-2. Codes After Servicing Interrupts Master Transmit Servicing the InterruptMaster Receive Mode Transmitting Each Data ByteTable 3-3. Status Codes After Each Data Byte Transmits All Bytes Transmit CompletelyTable 3-4. Master Receive Status Codes Table 3-5. Codes After Servicing Interrupt Master Receive Receiving Each Data Byte Table 3-6. Codes After Receiving Each Data ByteSlave Transmit Mode Slave Receive Mode Bus Arbitration Bus Clock ConsiderationsBus Clock Speed Clock SynchronizationTable 3-7. I 2C Controller Register Summary Programmer’s ReferenceI2C Controller Register Summary Resetting the I2C ControllerTable 3-8. Slave Address Register I2C Controller Register DefinitionsSlave Address Register General Call Address EnableTable 3-10. Data Register Data RegisterExtended Slave Address Control RegisterTable 3-12. Control Register Table 3-13. Control Register DefinitionsTable 3-14. Status Register Status RegisterTable 3-15. Status Register Definitions Table 3-16. Status CodesStatus Code Clock Control Register Table 3-17. Clock Control RegisterTable 3-18. Clock Control Register Definitions Table 3-22. Software Reset Register Definitions Software Reset RegisterExtended Slave Address Register Table 3-21. Software Reset Register4 USB Controller Serial Interface Engine USB BackgroundUSB Interrupt USB CoreBuffer Descriptor Table USB Hardware/Software InterfaceDigital Phase Lock Loop Logic Microprocessor InterfaceRx vs. Tx as a Target Device or Host Figure 4-1. Buffer Descriptor TableTable 4-3. 16-Bit USB Address Definitions Table 4-1. USB Data DirectionAddressing BDT Entries Table 4-2. 16-Bit USB AddressTable 4-5. USB Buffer Descriptor Format Table 4-4. BDT Data Used by USB Controller and MicroprocessorUSB Controller Determines… Microprocessor Determines…USB Ownership Table 4-6. USB Buffer Descriptor Format DefinitionsBD Owner DATA0/1 Transmit or ReceiveFigure 4-2. USB Token Transaction USB TransactionUSB Register Summary Table 4-7. USB Register SummaryDedicated to host mode Table 4-9. 16- Interrupt Status Register Definitions USB Register DefinitionsInterrupt Status Register Table 4-8. Interrupt Status RegisterUSB Reset Enable/Disable USBRST InterruptSleep Timer Error ConditionError Register Table 4-10. Error Interrupt Status RegisterTable 4-11. 16- Error Interrupt Status Register Definitions PID check field failed Error interrupt with two functionsData Field Received Not 8 Bits CRC16 FailureTable 4-13. Status Register Definitions Live USB Differential Receiver JSTATE SignalLive USB Single Ended Zero Signal Table 4-12. Status RegisterBDT PDD Reset USB Reset SignalHost Mode Enable valid for host mode only Resume SignalingAddress Register Table 4-14. Address RegisterTable 4-15. 16- Address Register Definitions Frame Number Frame Number RegistersTable 4-16. Frame Number Register Table 4-17. Frame Number Register DefinitionsToken Register Table 4-20. Valid PID Tokens Endpoint for Token CommandTable 4-18. Token Register Table 4-19. Token Register DefinitionsTable 4-22. Endpoint Control Register Definitions Endpoint Control RegistersEndpoint Enable Table 4-21. Endpoint Control RegistersTable 4-23. Endpoint Control Register Definitions Host Mode OperationFigure 3. Enable Host Mode and Configure a Target Device Sample Host Mode OperationsFigure 4. Full-Speed Bulk Data Transfers to a Target Device Figure 4-5. Pull-up/Pull-down USB USB Pull-up/Pull-down ResistorsClock CLK USB Interface SignalsUSB Output Enable HOST Mode Enable5 CAN Controllers Arbitration and Error Checking CANBUS BackgroundData Exchanges and Communication Table 5-1. Bit Rates for Different Cable Lengths CANBUS Speed and LengthRegister CAN Register SummariesRegister Summary Hex OffsetRegister Table 5-4. Detailed CAN Register Map Detailed CAN Register MapHex Offset Acceptance Filter Enable RegisterRegister Sending a Message CAN Register DefinitionsTX Message Registers Figure 5-1. TX Message RoutingTable 5-7. TxMessage0Data Tx Message RegistersTable 5-5. TxMessage0ID28 Table 5-6. TxMessage0ID12Message Data Table 5-12. TxMessage0Ctrl FlagsTable 5-13. TxMessage0 Register Definitions Message Identifier for Both Standard and Extended MessagesFigure 5-2. RX Message Routing RX Message RegistersTable 5-16. RxMessageID12 Rx Message RegistersTable 5-14. RxMessageID28 Table 5-15. Rx Message ID28 Register DefinitionsTable 5-23. Rx Message Data 23 Register Definitions Table 5-20. Rx Message DataTable 5-21. Rx Message Data 39 Register Definitions Table 5-22. Rx Message DataTable 5-29. Rx Message Msg Flags Register Definitions Table 5-26. RxMessage RTRTable 5-27. Rx Message RTR Register Definitions Table 5-28. Rx Message Msg FlagsTable 5-32. Error Status Error Count and Status RegistersTable 5-30. Tx/Rx Error Count Table 5-31. Tx\Rx Error Count Register Definitionstxlevel10 Table 5-34. Tx/Rx Message Level RegisterTable 5-35. Tx/Rx Message Level Register Definitions rxlevel10Format Error Interrupt FlagsNote The reset value of this register’s bits is indeterminate CRC ErrorBus Off State − int2n group error interrupts Interrupt Enable RegistersTable 5-38. Interrupt Enable Registers Table 5-39. Interrupt Enable Register DefinitionsOverload Condition − int3n group diagnostic interrupts CAN Operating ModeTable 5-40. Interrupt Enable Registers Table 5-41. Interrupt Enable Register DefinitionsTable 5-42. Bit Rate Divisor Register CAN Configuration RegistersConfiguration Bit Rate Figure 5-3. CAN Operating ModeCfgsjw Table 5-44. Configuration RegisterTable 5-45. Configuration Register Definitions Overwrite Last Messagetime quanta TQ Bit Timetseg1 + tseg2 +Table 5-48. Acceptance Mask 0 Register Acceptance Filter and Acceptance Code MaskTable 5-46. Acceptance Filter Enable Register Table 5-47. Acceptance Filter Enable Register DefinitionsD5556 Table 5-50. Acceptance Mask Register IDTable 5-51. Acceptance Mask Register ID12 Definitions Table 5-52. Acceptance Mask Register DataTable 5-57. Acceptance Mask Register ID12 Definitions Table 5-54. Acceptance Code RegisterTable 5-55. Acceptance Code Register Definitions Table 5-56. Acceptance Mask Register ID12Table 5-61. Arbitration Lost Capture Register Definitions CANbus AnalysisArbitration Lost Capture Register Table 5-60. Arbitration Lost Capture RegisterErrorcode Error Capture RegisterTable 5-62. Error Capture Register Table 5-63. Error Capture Register DefinitionsStuff Bit Inserted Table 5-65. Error Capture Register DefinitionsFrame Reference Register Table 5-64. Frame Reference RegisterFigure 5-5. CAN Bus Interface CAN Bus InterfaceInterface Connections Figure 5-6. CAN Connector+24V Figure 5-7. Power for CAN+5CAN GNDCAN0.01uf Figure 5-8. CAN Transceiver and Isolation Circuits