OPEN-DRAIN Operation | National CP3BT26 instruction

14.2OPEN-DRAIN OPERATION

A port pin can be configured to operate as an inverting open-drain output buffer. To do this, the CPU must clear the bit in the data output register (PxDOUT) and then use the port direction register (PxDIR) to set the value of the port pin. With the direction register bit set (direction = out), the value zero is forced on the pin. With the direction register bit clear (direction = in), the pin is placed in the TRI-STATE mode. If desired, the internal weak pull-up can be enabled to pull the signal high when the output buffer is in TRI- STATE mode.

CP3BT26

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National CP3BT26 manual OPEN-DRAIN Operation

Contents

National Semiconductor Corporation Block DiagramGeneral Description MAY Table of Contents Features Device Overview Advanced Audio Interface Bluetooth LLCCan Interface Quad Uart Versatile Timer Unit MICROWIRE/SPIACCESS.BUS Interface MULTI-FUNCTION Timer Development Support Power ManagementDMA Controller Serial Debug Interface LQFP-144 Signal DescriptionsCP3BT26 LQFP-128 X1CKO ResetX1CKI Bbclk Name Pins Primary Function Alternate Alternate Function PG6 PG4Sdat PG5 X1CKI CTS PE4 SelioWR0 WR1 SLE Dedicated Address Registers CPU ArchitectureGENERAL-PURPOSE Registers No carry or borrow occurred Carry or borrow occurred Processor Status Register PSRInterrupt Base Register Intbase 12 11 Reserved Is held in the Intbase register, which is not Configuration Register CFGWhen the IDT has 16-bit entries, and all ex Mode for the CR16B large model. Loadw 12R5, R6 Addressing ModesAddb R1, R2 Instruction SET Stacks Instruction Set Summary Mnemonic Operands Description LPR AshudLshd Tbit Popret RetxPush POP Wait StormpEiwait NOP IN/A MemoryOperating Environment Empty BUS Interface Unit BIUBUS Cycles BIU Control Registers Static Zone 0 Configuration Register SZCFG0 2 I/O Zone Configuration Register Iocfg WBR RBE Hold Wait Ipst Static Zone 1 Configuration Register SZCFG1Static Zone 2 Configuration Register SZCFG2 RAM Memory Access to PeripheralsWait and Hold States Flash Program/Data Memory System Configuration Registers Name Address Description System Configuration RegistersModule Configuration Register Mcfg Module Status Register Mstat Software Reset Register Swreset Flash Memory Organization Flash MemoryFlash Memory Protection Flash Memory Operations Main Block Write Main Block Page EraseMain Block Module Erase Information Block Module Erase Area BootInformation Block Words Empty Ispe CPU Reset BehaviorBoot Area Start-Up Operation Flash Memory Interface Registers FMIBDR/FSMIBDR Flash Memory 0 Write Enable Register FM0WER/FSM0WERFlash Memory 1 Write Enable Register FM1WER Flash Memory Information Block Data Register Fsmctrl Flash Data Memory 0 Write Enable Register FSM0WERFlash Memory Control Register Fmctrl FMSTART/FSMSTART FsmstatFsmpsr Flash Memory End Time Reload Register FMEND/FSMEND Flash Memory Auto-Read Register 2 FMAR2/ FSMAR2 FMRCV/FSMRCV FSMAR1Flash Memory Auto-Read Register 0 FMAR0/ FSMAR0 DMA Channel Assignment Peripheral Trans Register Action DMA ControllerChannel Assignment Transfer Types Operation Modes DMA Controller Register SET Debug ModeSoftware DMA Request Device B Address Register ADRBn Device a Address Counter Register ADCAnDevice a Address Register ADRAn Device B Address Counter Register ADCBn DMA Control Register DMACNTLn Block Length Register BLTRn VLD DMA Status Register DmastatVLD Chac OVR Interrupt Controller Registers InterruptsNON-MASKABLE Interrupts Maskable Interrupts Non-Maskable Interrupt Status Register Nmistat Interrupt Vector Register IvctExternal NMI Trap Control and Status Register Exnmi Interrupt Status Register 2 ISTAT2 Interrupt Enable and Mask Register 1 IENAM1Interrupt Enable and Mask Register 2 IENAM2 Interrupt Status Register 1 ISTAT1 IRQ Number Description Maskable Interrupt SourcesNested Interrupts Maskable Interrupts Assignment IRQ Number Description Triple Clock and Reset Module Triple Clock and Reset Capacitor C1, C2 Capacitance External Crystal NetworkCrystal Resonance Frequency Type Min. Q factor Main ClockSlow Clock PLL Clock System Clock POWER-ON ResetExternal Reset Clock and Reset Registers MODE20 Module Activity Summary Power Mode Clock Power ManagementActive Mode Power Save Mode Power Management Control Register Pmmcr Idle Mode Power Management RegistersHalt Mode Power Management Registers Name Address Description Hcch DHCHccm OHC Active Mode to Power Save ModeOHC OMC OLC Wake-Up Transition to Active Mode Entering Idle ModeEntering Halt Mode Software-Controlled Transition to Active Mode Multi-Input Wake-Up Multi-Input Wake-Up Module Block Diagram Multi-Input Wake-Up Registers Name Address Description MULTI-INPUT WAKE-UP RegistersMiwu Sources Miwu Channel Wake-Up 1 Edge Detection Register WK1EDG Wake-Up Interrupt Enable Register WK0IENAWake-Up 1 Interrupt Enable Register WK1IENA Wake-Up Enable Register WK0ENA WK1ICTL1 WK1ICTL2 Wake-Up Interrupt Control RegisterWK0ICTL1 WK0ICTL2 Wake-Up 1 Interrupt Control Register Wake-Up 1 Pending Clear Register WK1PCL Wake-Up Pending Register WK0PNDWake-Up Pending Clear Register WK0PCL Wake-Up 1 Pending Register WK1PND Programming Procedures Port Registers Input/Output Ports Address Description Port Registers Port Direction Register PxDIR Port Alternate Function Register PxALTPort Data Input Register PxDIN Port Data Output Register PxDOUT Port Pin PxALTS = Port High Drive Strength Register PxHDRVPort Alternate Function Select Register PxALTS Alternate Function Select OPEN-DRAIN Operation Rfdata Bluetooth ControllerRF Interface X1CKI/BBCLK Sdat Serial InterfaceRfce Sclk Serial Interface Write Timing Read Operation Write Operation First part of read cycle driven by CP3BT26. Address is 0Ah Bit, and register address for a read cycle. In the second 15.4 LMX5252 POWER-UP Sequence 15.3 LMX5251 POWER-UP Sequence Bluetooth Sequencer RAM Bluetooth Sleep ModeBluetooth Global Registers Bluetooth Shared Data RAM Data Path 16.0 12-Bit Analog to Digital ConverterFunctional Description Pen-Down Detector OperationADC Clock Generation ADC Voltage References Touchscreen Interface Touchscreen Driver Configuration RYP Measuring Pen ForceRX2 RY2 ADC Registers Name Address Description ADC Operation in POWER-SAVING ModesFreeze ADC Register SET Touchcfg ADC0/TSX+ ADC1/TSY+ ADC2/TSX ADC3/TSY Muxcfg Clkdiv PrefcfgNrefcfg ADC Start Conversion Register Adcstart ADC Start Conversion Delay Register AdcscdlyADC Conversion Control Register Adccntrl Sign ADC Result Register AdcresltAdcresult Adcoflw Random Number Generator RNG RNG Module Block Diagram Random Number Generator Register SET Functional States USB Controller TX Fifo RX Fifo Endpoint Operation Transmit Endpoint Fifo Operation TXFIFO1, TXFIFO2, TXFIFO3 Bidirectional Control Endpoint FIFO0 Operation USB Controller Registers Name Address Description USB Controller RegistersReceive Endpoint Fifo Operation RXFIFO1, RXFIFO2, RXFIFO3 Main Control Register Mcntrl NFS Node Functional State Register NfsrNFS USB Functional States Alternate Event Register Altev Main Event Register MaevMain Mask Register Mamsk Transmit Mask Register Txmsk Alternate Mask Register AltmskTransmit Event Register Txev NAK Mask Register Nakmsk Receive Event Register Rxev NAK Event Register NakevReceive Mask Register Rxmsk Fifo Warning Mask Register Fwmsk Fifo Warning Event Register FwevFrame Number High Byte Register FNH Dsrc DMA Event Register Dmaev DMA Count Register Dmacnt DMA Error Register DmaerrDMA Mask Register Dmamsk Mirror Register MIR Transmit Status 0 Register TXS0 Transmit Command 0 Register TXC0Endpoint Control 0 Register EPC0 Receive Status 0 Register RXS0 Receive Command 0 Register RXC0Transmit Data 0 Register TXD0 Transmit Status Register n TXSn Receive Data 0 Register RXD0Endpoint Control Register n EPCn RFF Transmit Command Register n TXCnTfwl Last Bytes Remaining in Fifo Transmit Fifo Warning LimitReceive Status Register n RXSn Tfwl Rfwl Receive Command Register n RXCn Receive Data Register n RXDTransceiver Interface Receive Fifo Warning Limit Can Module Basic can Concepts Can Block Diagram Arbitration Field Can Frame TypesCan Frame Fields Start of Frame SOF ACK Field Data Length Code DLCData Field Cyclic Redundancy Check CRC Cyclic Redundancy Check Field CRC Remote FrameData Field Error Frame Overload Frame Error Frame Acknowledgment Error Stuff ErrorForm Error Bit CRC Error Error Counters Error ActiveError Warning Error Passive Bit Timing Bit Time LogicCan Bit Time Synchronization CKI Message Transfer From the can bus Gmask and BMASK. shows Acceptance FilteringExample 1 Acceptance of a Single Identifier Two 32-bit masks are used to filter unwanted messages 120 Receive Structure Rxbusy Receive ProcedureReceive Timing Writing to Buffer Status Code During 122 Buffer Read Routine Bufflock Enabled Transmit Priority Transmit StructureTransmit Scheduling PRI Txpri TX Buffer States Interrupts IRQ IST3 IST2 IST1 IST0 Time Stamp Counter Message Buffer Map Address Register CPU Access to can Registers/MemoryMemory Organization Message Buffer Organization Buffer Status/Control Register Cnstat Can Controller RegistersCan Controller Registers Name Address Description Buffer Status Buffer Status Section of the Cnstat RegisterST3 DIR ST2 ST1 ST0 Busy Standard Frame with 8 Data Bytes Address Buffer Register Data Length CodingDLC Storage of Standard Messages PRI SRR Extended Messages with 8 Data Bytes Address Buffer RegisterCnstat DLC Extended Remote Frame Address Buffer Register Frame is received, the contents of these registers will beContents of these registers are ignored. If a remote Storage of Remote Messages Can Global Configuration Register Cgcr Dress, as shown in Figure Listen Only bit can be used to configureWhen the Ignore Acknowledge bit is set, When the Loopback bit is set, all messages SJW Xrtr TSEG1TSEG2 RTR IDE BM170 Can Interrupt Enable Register CienBasic Mask Register BMSKB/BMSKX Basic Mask BM2818 IRQ EFID30 Can Error Counter Register CanecCan Error Diagnostic Register Cediag Error Field Identifier External Connection Can Timer Register CtmrExternal can Pins Signal Name Type Description System START-UP and MULTI-INPUT WAKE-UP Remote Frames Minimum Clock Frequency Requirements Baud RateBit Time Logic Calculation Examples Acceptance Filter Considerations Usage Hint Audio Interface Modes Audio Interface SignalsAdvanced Audio Interface DMA Support Synchronous ModeNormal Mode 145 Audio Interface Operation Clock ConfigurationFrame Clock Generation BIT Clock Generation Receive TransmitDMA Operation Fifo Operation Data Word Length Frame Sync SignalCommunication Options Short and Long Frame Sync Pulses Audio Control Data 150 IOM-2 ModeLoopback Mode Audio Interface Registers Name Address Description Freeze ModeAudio Interface Registers Audio Transmit DMA Register n ATDRn Audio Receive Fifo Register ArfrAudio Transmit Fifo Register Atfr Audio Receive DMA Register n ARDRn FSL Audio Global Configuration Register AgcrSlots per Mode Frame SCS Txeip Audio Interrupt Status and Control Register AiscrTxeip Txip Rxeip Rxip Txeie Txie Rxeie Rxie Txeic Txic Rxeic Rxic Rxie Audio Receive Status and Control Register Arscr Rxsa Bit Slots EnabledRxdsa Bit Slots Enabled For DMA Audio Transmit Status and Control Register Atscr Txsa Bit Slots EnabledTxdsa Bit Slots Enabled For DMA DMA Request Condition Audio Clock Control Register AccrAudio DMA Control Register Admacr RMD PCM Conversions CVSD/PCM Conversion ModuleOperation Interrupt Generation Cvsd ConversionPCM to Cvsd Conversion Cvsd to PCM Conversion CVSD/PCM Converter Registers Linearout Cvsd Status Register Cvstat Uart Operation Uart ModulesFunctional Overview Uart Asynchronous Communication Uart Block Diagram Frame Format Selection Diagnostic Mode Prescaler Factor Prescaler Factors Parity Generation and Detection Break Generation and Detection Uart Registers Name Address Description Uart Registers Uart Frame Select Register UnFRS Uart Baud Rate Divisor UnBAUDUart Receive Data Buffer UnRBUF Uart Transmit Data Buffer UnTBUF Uart Status Register UnSTAT Uart Mode Select Register 1 UnMDSL1 Oversampling Rate Uart Interrupt Control Register UnICTRLUart Oversample Rate Register UnOVR UOVSR30 Oversampling Rate Sample Position Uart Mode Select Register 2 UnMDSL2Baud Rate Calculations Uart Sample Position Register UnSPOS 173 174 Shifting Microwire/SPI InterfaceMicrowire Operation Microwire Interface Clocking Modes Writing Normal Mode Scidl = Master Mode MWCTRL1 Slave ModeMicrowire Interrupt Trigger Condition Status Enable Bit Mwen Microwire Interface Registers OVR RBF BSY Microwire Status Register MwstatSCM Scdv Start and Stop ACCESS.bus InterfaceACB Protocol Overview Data Transactions Arbitration on the Bus Acknowledge CycleAddressing Transfer Formats ACB Functional Description Slave Error Detections Master Error DetectionsBus Idle Error Recovery Slave Mode ACCESS.BUS Interface Registers ACB Control Status Register Acbcst Stop TgsclACB Control Register 1 ACBCTL1 Start ACB Control Register 3 ACBCTL3 ACB Control Register 2 ACBCTL2 Saen Usage HintsACB Own Address Register 1 ACBADDR1 Saen Addr 190 Avoiding Bus Error During Write Transaction 191 TWM Structure Timer T0 OperationTiming and Watchdog Module Register Locking Power Save Mode OperationWatchdog Operation TWM Registers T0IN Mdiv Watchdog Count Register Wdcnt Watchdog Programming ProcedureWatchdog Service Data Match Register Wdsdm TWMT0 Control and Status Register T0CSR 196 Multi-Function TimerTimer Structure Clock Source Block Counter Clock Source Select Timer Operating ModesPulse Accumulate Mode Limitations in Low-Power Modes 198 Mode 1 Processor-Independent PWM Dual-Input Capture Mode Mode 2 Dual Input Capture 200 Mode 3 Dual Independent Timer/Counter Input Capture Plus Timer Mode Mode 4 Input Capture Plus Timer Tben Timer InterruptsTimer I/O Functions Taen Timer Registers Reload/Capture B Register Tcrb Timer Mode Control Register TctrlReload/Capture a Register Tcra Timer Interrupt Clear Register Ticlr Timer Interrupt Control Register Tictl 206 Versatile Timer Unit VTUVTU Functional Description VTU PWM Generation Dual 8-bit PWM Mode 208 VTU 16-bit PWM Mode Dual 16-Bit Capture Mode ISE Mode operation VTU Dual 16-bit Capture Mode Low Power Mode VTU Registers Name Address Description Mode Control Register ModeVTU Registers Interrupt Control Register Intctl CxEDG Capture Counter Reset Clock Prescaler Register 2 CLK2PS Clock Prescaler Register 1 CLK1PSInterrupt Pending Register Intpnd Period/Capture Register n PERCAPx Counter Register n COUNTxCNTx Duty Cycle/Capture Register n DTYCAPx Register Map Bluetooth LLC Registers USB Node Registers Register Name Size Address Access Value After Comments Type EPC4 EPC1TXC1 EPC2 Can Module Message Buffers DMA Controller Can Registers Bus Interface Unit Flash Data Memory Interface System ConfigurationFlash Program Memory Interface CVSD/PCM Converter Triple Clock + Reset General-Purpose I/O Ports Multi-Input Wake-Up Comments Type Register Name Size Address Interrupt Control Unit Advanced Audio Interface UART1 UART0 UART3 UART2 Timing and Watchdog ACCESS.busMulti-Function Timer ADC Versatile Timer Unit Word FF F284h RNGRngcst Rngd Register Bit Fields USB Fwmsk RXWARN31 Setup Toggle Rxlast Rcount RXC0IGN Ignout Rxen Setup EPC1 Nakev OUT Nakmsk Fwev RXWARN31 Control Status Can Dmac Memory Registers Flash System Configuration RegistersBIU TBI Register Flash Data Memory CLK3RES CVSD/PCM AAI PMM RegisterMIWU16 Gpio Registers Uart ICU Registers MFT16 MWSPI16ACB Registers VTU Rngdivh RngcstImsk Rngd TBD Electrical CharacteristicsSymbol Parameter Conditions Min Max Units Absolute Maximum Ratings IOOff DNL Symbol Parameter Conditions Min Typ Max UnitsINL LSB Flash Memory ON-CHIP Programming TRI-STATE Output Signal LevelsClock and Reset Timing Reset and NMI Input Signals Clock Timing NMI Signal Timing Uart Timing Uart Output Signals 30.9 I/O Port Timing Port Output Signals Advanced Audio Interface AAI Timing AAI Output Signals Receive Timing, Long Frame Sync Transmit Timing, Short Frame Sync Microwire/SPI Output Signals MICROWIRE/SPI TimingMicrowire/SPI Signals Symbol Description Reference Min ns Microwire/SPI Input Signals 254 Normal Mode After FE onMicrowire Data Out Valid Alternate Mode After RE On MSK Propagation Time 255 256 Microwire Transaction Timing, Alternate Mode, Scidl = 257 ACCESS.bus Output Signals ACCESS.BUS Timing 259 260 ACB Data Timing MULTI-FUNCTION Timer MFT Timing USB Port AC Characteristics 262 Versatile Timing Unit VTU TimingTIOx Input High Time Rising Edge RE on CLK TIOx Input Low Time RE on CLK External BUS Timing External Bus Output Signals 264 Early Write Between Normal Read Cycles No Wait States 265 266 Consecutive Normal Read Cycles Burst, No Wait States 267 268 Early Write Between Fast Read Cycles X1CKO X1CKI Pin AssignmentsLQFP-128 Package PWR SDA ADC0 TSX+ Reset TMSAvcc PWR Adgnd Advcc Uvcc X2CKI X2CKO ENV2 PF1 MDIDO/TIO2 PE0 RXD0 Gpio PE1 TXD0 PE2 RTS PE3 CTS PE4 CKX/TB PE5SRFS/NMI PF0 MSK/TIO1 272 LQFP-144 Package ADC7 Adcin SCL SDA ADC0 TSX+ADC4 MUXOUT0 ADC5 MUXOUT1 Pin Name Alternate Functions Pin Number Type A10 A22 A21 A20 A19 A18 A17 A16 A15 A14 A13A12 A11 Date Major Changes From Previous Version Revision HistoryRevision History LQFP-128 Package LQFP-144 Package Physical Dimensions millimeters unless otherwise noted Banned Substance Compliance Form when properly used in accordance with instructionsLife Support Policy