Manuals / Intel / Computer Equipment / Computer Hardware

Intel Embedded Microcontroller Serial Port Special Function Registers, A8H, B8H, TXD RXD Sbuf

Models: Embedded Microcontroller 8XC251SP 8XC251SA 8XC251SQ 8XC251SB

1 458

Download 458 pages 25.38 Kb

Page 174

8XC251SA, SB, SP, SQ USER’S MANUAL

Table 10-2. Serial Port Special Function Registers

Mnemonic	Description	Address

SBUF	Serial Buffer. Two separate registers comprise the SBUF register. Writing	99H
	to SBUF loads the transmit buffer; reading SBUF accesses the receive
	buffer.

SCON	Serial Port Control. Selects the serial port operating mode. SCON enables	98H
	and disables the receiver, framing bit error detection, multiprocessor
	communication, automatic address recognition, and the serial port interrupt
	bits.

SADDR	Serial Address. Defines the individual address for a slave device.	A8H

SADEN	Serial Address Enable. Specifies the mask byte that is used to define the	B8H
	given address for a slave device.

IB Bus

Write SBUF	Read SBUF

TXD

RXD

RI

SBUF

(Transmit)

Mode 0

Transmit

TI

SBUF

(Receive)

Load SBUF

Receive

Shift Register

Interrupt

Request

	Serial I/O	SCON
	Control	SCON
	Control

A4123-02

Figure 10-1. Serial Port Block Diagram

10-2

Image 174

Intel Embedded Microcontroller, 8XC251SA Serial Port Special Function Registers, Mnemonic Description Address, A8H, B8H

Contents

Page Page May 1996 Order Number Copyright Intel Corporation Contents 8XC251SA, SB, SP, SQ USER’S Manual Chapter TIMER/COUNTERS and Watchdog Timer Chapter Serial I/O Port Multiprocessor Communication Modes 2 Framing BIT Error Detection Modes 1, 2,Modes of Operation Automatic Address RecognitionChapter External Memory Interface Appendix a Instruction SET Reference Figures 10-1 13-24 Address Space for Example Tables INC/DEC Tables Page Guide to This Manual Page Manual Contents Chapter Guide to this Manual8XC251SA, SB, SP, SQ USER’S Manual Notational Conventions and Terminology ItalicsInstructions Units of Measure Related DocumentsData Sheet Application NotesService Canada Asia-Pacific and Japan Europe Application Support ServicesIntel Application Support Services World Wide Web CompuServe ForumsFaxBack Service Bulletin Board System BBSGuide to this Manual Page Architectural Overview Page Chapter Architectural Overview Functional Block Diagram of the 8XC251SA, SB, SP, SQ MCS 251 Microcontroller CoreOn-chip Memory Device XC251SA, SB, SP, SQ Features8XC251SA, SB, SP, SQ Architecture OTPROM/EPROMMCS 251 Microcontroller Core ALU 1 CPUSRC1 SRC2 DSTClock and Reset Unit XTAL1On-chip Code Memory Timer/Counters and Watchdog TimerInterrupt Handler On-chip RAMProgrammable Counter Array PCA Serial I/O PortAddress Spaces Page Address Spaces for MCS 251 Microcontrollers FfffffhS1FFH Compatibility with the MCS 51 Architecture Movx FfffhMovc FFHS1FFH FF0000H-FFFFFFH8XC251SA, SB, SP, SQ Memory Space Feffffh 01FFFFH00FFFFH FFFFF7H On-chip General-purpose Data RAM Accessing On-chip Code Memory in Region Minimum Times to Fetch Two Bytes of CodeType of Code Memory External Memory 8XC251SA, SB, SP, SQ Register FileDR8 WR8WR0 WR2 WR4 WR6 DR0 DR4Bank Address Range PSW Selection Bits RS1 RS0Byte, Word, and Dword Registers Dedicated RegistersAccumulator and B Register Dpxl SPH SbehSPH DPHRegister File Name Mnemonic Location Extended Data Pointer, DPXExtended Stack Pointer, SPX SFRs MnemonicSpecial Function Registers Sfrs XC251SA, SB, SP, SQ SFR Map and Reset Values Core SFRs I/O Port SFRsMnemonic Name Address 10. Programmable Counter Array PCA SFRs Timer/Counter and Watchdog Timer SFRsSerial I/O SFRs Mnemonic NameCCAP0L SE9HSF9H SeahDevice Configuration Page Configuration Overview Device ConfigurationConfiguration Array On-chip Configuration Array External Configuration Bits External Addresses for Configuration ArraySize of External Address Configuration Byte Location Selector Ucon UCONFIG0 1 Bit Function Number MnemonicWSA1# WSA0# UCONFIG1 1 WSB1# WSB0#Memory Signal Selections RD10 Configuring the External Memory InterfaceMode and Nonpage Mode PAGE# PSEN# WR#Configuration Bits RD10 2.1 RD10 = 00 18 External Address Bits2.2 RD10 = 01 17 External Address Bits RD10 = PSEN#, WR#Internal/External Address Mapping RD10 = 10 PSEN#Configuration Bit WSB Wait State Configuration BitsConfiguration Bits WSA10#, WSB1# 2.3 RD10 = 10 16 External Address BitsRD#, WR#, PSEN# External Wait States Opcode Configurations SRCConfiguration Bit XALE# 8XC251SxExamples of Opcodes in Binary and Source Modes Selecting Binary Mode or Source ModeInstruction Opcode Binary Mode Source Mode DEC aBinary Mode Opcode Map Source Mode Opcode MapInterrupt Mode Intr Mapping ON-CHIP Code Memory to Data Memory EMAP#Programming Page Source Mode or Binary Mode Opcodes Programming Features of the MCS 251 ArchitectureAddress Notation Data TypesRegister Notation Data TypesA3H B6H A3H B6H WR0 MOV WR0,#A3B6HRegister Destination Source Register Range Addressing Modes Data InstructionsData Addressing Modes Register Addressing ImmediateDirect 0000H-FFFFH @DPTR, @A+DPTR Indirect00H-FFH 0000H-FFFFH @A+DPTR, @A+PC@WR30 + Ffffh Displacement Arithmetic InstructionsLogical Instructions Data Transfer Instructions Bit-addressable Locations BIT InstructionsBit Addressing Architecture Bit-addressable LocationsAddressing Two Sample Bits Location Addressing MCS Mode ArchitectureControl Instructions Addressing Modes for Bit InstructionsAddressing Modes for Control Instructions Addressing Modes for Control InstructionsDescription Address Bits Address Range Operand Relation Type Conditional JumpsCompare-conditional Jump Instructions JNE JGE JLEUnconditional Jumps Calls and ReturnsProgram Status Words 10. The Effects of Instructions on the PSW and PSW1 Flags Instruction Type Flags Affected 1RS0 PSWRS1 Bank AddressProgram Status Word 1 Register PSW1Page Interrupt System Page Overview Interrupt System Pin SignalsSignal Type Description Multiplexed WithInterrupt Enable Priority Enable Interrupt System Special Function Registers 8XC251SA, SB, SP, SQ Interrupt SourcesExternal Interrupts Description AddressPCA Timer InterruptsInterrupt Control Matrix INT1#Interrupt Enable Programmable Counter Array PCA InterruptSerial Port Interrupt IE0 ET2ET1 EX1 ET0 EX0 Interrupt Priority Within Level Interrupt PrioritiesLevel of Priority IPH0.x MSB IPL0.x LSB Priority LevelIPH0 IPL0Interrupt Processing Interrupt ProcessMinimum Fixed Interrupt Time Variable Interrupt ParametersResponse Time Variables Response Time Example #1 A4154-02 Actual vs. Predicted Latency Calculations Interrupt Latency VariablesLatency Calculations T2EXBlocking Conditions Interrupt Vector CycleISRs in Process Page Input/Output Ports Page INPUT/OUTPUT Port Overview Input/Output Port Pin DescriptionsPin Type Alternate Alternate Description Name Pin Name I/O Configurations Port 1 and PortPort 0 and Port Port 1 and Port 3 Structure Port 0 StructurePort 2 Structure READ-MODIFY-WRITE Instructions QUASI-BIDIRECTIONAL Port Operation External Memory Access Port Loading8XC251SA, SB, SP, SQ USER’S Manual Instructions for External Data Moves InstructionsPage Timer/Counters Watchdog Timer Page TIMER/COUNTER Overview TIMER/COUNTER OperationS8BH S8AHS8CH S8DHSignal Type Description Alternate Name Function TimerExternal Signals Timer 10 External Clock Inputs. When timer 10 operates as aMode 0 13-bit Timer Mode 1 16-bit TimerMode 2 8-bit Timer With Auto-reload Mode 3 Two 8-bit TimersTR0 GATE0 TR1M11 M01 TmodGATE1 M10 M00Tcon TF1 TR1 TF0 TR0IE1 IT1 IE0 IT0 Mode 3 Halt Timer 0/1 ApplicationsAuto-load Setup Example Timer Pulse Width MeasurementsTF2 Capture ModeXTAL1 TH2 TL2 TR2RCAP2H RCAP2L TF2 Auto-reload ModeUp Counter Operation EXF2 EXEN2TH2 TL2 2.2 Up/Down Counter OperationXTAL1 EXF2 RCAP2H RCAP2L T2EXBaud Rate Generator Mode Clock-out ModeRCAP2H RCAP2L T2OERclk or Tclk CP/RL2# T2OE T2MOD Watchdog TimerDescription Xxxx XX00B T2OE DcenEXEN2 TR2 T2CONTF2 EXF2 Rclk Tclk CP/RL2#Using the WDT WDT During Idle ModeWDT During PowerDown Programmable Counter Array Page Chapter Programmable Counter Array PCA DescriptionPCA TIMER/COUNTER Alternate Port UsagePCA CCON.7 P1.6/CEX3/WAIT#A17/WCLK CPS1 CPS0 Cidl ECF CMOD.2 CMOD.1 CMOD.7 CMOD.0 IDLPCA Compare/Capture Module Mode Registers. Contain bits for PCA Special Function Registers SFRsCompare/Capture Module External I/O. Each compare/capture 1 16-bit Capture Mode PCA COMPARE/CAPTURE ModulesPCA 16-bit Capture Mode 3 16-bit Software Timer Mode Compare ModesHigh-speed Output Mode PCA Software Timer and High-speed Output ModesPCA Watchdog Timer Mode CCAP4H CCAP4L Wdte CMOD.6 ECOM4Pulse Width Modulation Mode PCA 8-bit PWM ModePWM Variable Duty Cycle CPS1 CPS0 ECF CmodCidl Wdte CPS1 CPS0CCF4 CCF3 CCF2 CCF1 CCF0 TOGx PWMx ECCFx Module ModeCcon Bit Function NumberCCAPMx x = CCAPM1 Sdbh CCAPM2 Sdch CCAPM3 Sddh CCAPM4 SdehPage Serial I/O Port Page Serial Port Signals Function Type Description MultiplexedA8H Serial Port Special Function RegistersMnemonic Description Address B8HMode Description Baud Rate SconSM0 SM1 Synchronous Mode Mode Transmission ModeModes of Operation Transmit ReceiveAsynchronous Modes Modes 1, 2, Reception Modes 1, 2Framing BIT Error Detection Modes 1, 2, Multiprocessor Communication Modes 2Automatic Address Recognition Given Address SaddrBroadcast Address Saddr or SadenBaud Rates for Mode Reset AddressesBaud Rate for Mode Baud RatesTimer 1 Generated Baud Rates Modes 1 Selecting Timer 1 as the Baud Rate GeneratorSelecting Timer 2 as the Baud Rate Generator Timer 1 Generated Baud Rates for Serial I/O Modes 1Timer 2 Generated Baud Rates Modes 1 SMOD1Selecting the Baud Rate Generators Rclck TclckReceiver Transmitter Bit Timer 2 Generated Baud Rates Oscillator Baud RateRCAP2H Minimum Hardware Setup Page Minimum Hardware Setup Minimum SetupElectrical Environment Power and Ground PinsUnused Pins Noise ConsiderationsClock Sources On-chip Oscillator CrystalXTAL1 XTAL2 On-chip Oscillator Ceramic Resonator External ClockCmos Reset External Clock Drive WaveformsExternally Initiated Resets WDT Initiated ResetsReset Operation Power-on Reset RST Xtal PSEN# ALESpecial Operating Modes Page General Power Control RegisterPower Off Flag Serial I/O Control BitsGF1 GF0 IDL PconSMOD1 SMOD0 POF SMOD1Pin Conditions in Various Modes Mode ProgramPort Memory Pin Pins ALE PSEN#Idle Mode Entering Idle ModeExiting Idle Mode Powerdown ModeEntering Powerdown Mode Exiting Powerdown ModeON-CIRCUIT Emulation Once Mode Entering Once ModeExiting Once Mode Page External Memory Interface Page Chapter External Memory Interface Address Line 16. See RD# External Memory Interface SignalsAddress Line RD1 RD0Bus Cycle Definitions Mode Bus Cycle Bus Activity StateExternal BUS Cycles Bus Cycle Definitions No Wait StatesNonpage Mode Bus Cycles External Code Fetch Nonpage ModeMode Bus Cycles External Data Write Nonpage ModeExternal Code Fetch Page Mode External Data Read Page Mode External BUS Cycles with Configurable Wait States Wait StatesExtending RD#/WR#/PSEN# External Code Fetch Nonpage Mode, One RD#/PSEN# Wait State Extending ALE External BUS Cycles with REAL-TIME Wait StatesWcon SA7HXxxx XX00B Rtwce Rtwe Real-time WAIT# Enable Rtwe Real-time Wait Clock Enable RtwceReal-time Wait State Bus Cycle Diagrams Wclk ALE RD#/PSEN# Wclk ALE WR#14. External Data Read Page Mode, RT Wait State Configuration Byte BUS Cycles Nonpage ModePort Bit/16-bit Nonpage Mode Port 0 and Port 2 Pin Status in Nonpage ModePort 0 and Port 2 Pin Status In Normal Operating Mode Port 0 and Port 2 StatusPort 0 and Port 2 Pin Status in Page Mode External Memory Design Examples Example 1 RD10 = 00, 18-bit Bus, External Flash and RAM18. Address Space for Example 19. Bus Diagram for Example 2 80C251SB in Page Mode Example 2 RD10 = 01, 17-bit Bus, External Flash and RAM20. Address Space for Example Example 3 RD10 = 01, 17-bit Bus, External RAM 22. Address Space for Example Example 4 RD10 = 10, 16-bit Bus, External RAM PROM/EPROM24. Address Space for Example An Application Requiring Fast Access to the Stack An Application Requiring Fast Access to DataExample 5 RD10 = 11, 16-bit Bus, External Eprom and RAM 25. Bus Diagram for Example 5 80C251SB in Nonpage Mode Eprom RAM27. Bus Diagram for Example 6 80C251SB in Page Mode Example 6 RD10 = 11, 16-bit Bus, External Eprom and RAM28. Bus Diagram for Example 7 80C251SB in Page Mode Example 7 RD10 = 01, 17-bit Bus, External FlashProgramming Verifying Nonvolatile Memory Page Chapter Programming and Verifying Nonvolatile Memory Programming Considerations for On-chip Code Memory General Setup Eprom DevicesProgramming and Verifying Modes PROG# Programming and Verifying ModesRST PSEN# Port AddressProgramming Algorithm 8XC251SVerify Algorithm Programmable FunctionsProgramming Cycle Configuration Bytes Lock Bit SystemLock Bit Function Encryption ArraySignature Bytes Lock Bits Programmed Protection TypeContents of the Signature Bytes Verifying the 83C251SA, SB, SP, SQ ROMPage Instruction Set Reference Page Appendix a Instruction SET Reference Register Notation Notation for Instruction OperandsTable A-1. Notation for Register Operands MCSTable A-2. Notation for Direct Addresses Table A-3. Notation for Immediate AddressingTable A-4. Notation for Bit Addressing Opcode MAP and Supporting Tables Table A-6. Instructions for MCS 51 MicrocontrollersTable A-7. New Instructions for the MCS 251 Architecture Bin A5x8 A5x9 A5xA A5xB A5xC A5xD A5xE A5xF SrcInstruction Table A-8. Data InstructionsTable A-9. High Nibble, Byte 0 of Data Instructions ByteTable A-10. Bit Instructions Table A-11. Byte 1 High Nibble for Bit InstructionsBit Instruction Eret Table A-12. PUSH/POP InstructionsTable A-13. Control Instructions TrapTable A-14. Displacement/Extended MOVs Table A-15. INC/DEC Table A-16. Encoding for INC/DECTable A-17. Shifts Execution Times for Instructions that Access the Port SFRs Instruction SET SummaryTable A-18. State Times to Access the Port SFRs CaseInstruction SET Reference Add ADD dest,src Instruction SummariesTable A-19. Summary of Add and Subtract Instructions Subtract SUB dest,srcCompare CMP dest,src Dest,src Binary Mode Source ModeTable A-20. Summary of Compare Instructions CMPMUL AB Table A-21. Summary of Increment and Decrement InstructionsINC Dptr DIV ABCPL a Table A-23. Summary of Logical InstructionsCLR a RXX aSRA SRLSwap Move with Zero Extension Movz dest,src Binary Mode Source ModeTable A-24. Summary of Move Instructions Move from External Mem Movx dest,srcDir16,Rm Byte reg to dir addr 64K Dir16,WRj Movz MovhMovs Movc @A+DPTRXchd Table A-25. Summary of Exchange, Push, and Pop InstructionsXCH PushMove Bit from Carry MOV bit,CY Mnemonic Src,dest Binary Mode Source ModeTable A-26. Summary of Bit Instructions SetbTable A-27. Summary of Control Instructions States BytesDjnz JSGCjne NOPTable A-28. Flag Symbols Instruction DescriptionsADD dest,src Function Add Variations ADD A,#data Binary ModeEncoding Hex Code Operation ADD R1,R0ADD ADD DRkd,DRks Binary Mode Source Mode Bytes States Encoding ADD Rm,#data Binary ModeADD Rm,dir8 Binary Mode Source Mode Bytes States Encoding ADD WRj,#data16 Binary ModeADD DRk,#0data16 Binary Mode ADD WRj,dir8 Binary ModeADD Rm,@WRj Binary Mode Source Mode Bytes States Encoding WRj ← WRj + dir8 ADD Rm,dir16 Binary ModeRm ← Rm + dir16 ADD WRj,dir16 Binary Mode WRj ← WRj + dir16Addc A,src Function ADD Rm,@DRk Binary Mode Source Mode Bytes4 States4 EncodingVariations Addc A,#data Binary Mode FlagsAddc Ajmp addr11 Function Description Flags Example Ajmp JmpadrANL A,#data Binary Mode Variations ANL dir8,A Binary Mode Source Mode Bytes StatesHex Code Binary Mode = Encoding ANL R1,R0ANL ANL WRjd,WRjs Binary Mode Source Mode Bytes States Encoding ANL WRj,#data16 Binary ModeWRjd ← WRjd Λ WRjs Rm ← Rm Λ dir16 ANL WRj,dir16 Binary Mode Binary Mode = A5Encoding Source Mode = Encoding OperationANL WRj,dir8 Binary Mode WRj ← WRj Λ dir8Hex Code Binary Mode = A5Encoding Source Mode = Encoding ANL Rm,@WRj Binary Mode Source Mode Bytes States EncodingANL Rm,@DRk Binary Mode ANL CY,src-bitANL CY,bit Binary Mode Source Mode Bytes States ANL CY,bit51 Binary Mode Source Mode Bytes StatesANL CY,/bit51 Binary Mode Source Mode Bytes States MOV CY,P1.0Reqlow ANL CY,/bit Binary Mode Source Mode Bytes StatesCjne dest,src,rel Wait Cjne A,P1,WAITElse Variations Cjne A,#data,relThen Cjne A,dir8,relCjne Rn,#data,rel Not TakenCLR a CLR Bit51 ←CLR CY CMP dest,src Function CLR bit Binary Mode Source Mode Bytes StatesVariations CMP Rmd,Rms Binary Mode CMP R1,R0DRkd DRks CMP Rm,#data Binary Mode CMP WRjd,WRjs Binary ModeWRjd WRjs CMP DRkd,DRks Binary Mode CMPCMP WRj,#data16 Binary Mode CMP Rm,dir8 Binary ModeCMP WRj,dir8 Binary Mode CMP Rm,dir16 Binary ModeRm dir16 CMP WRj,dir16 Binary Mode CMP Rm,@DRk Binary Mode Source Mode Bytes States Encoding CPL aCPL CPL CYCPL bit Binary Mode Source Mode Bytes States Operation CPLAddc A,R3 DA a DEC byte FunctionDEC a DECDEC Rn Bytes States Encoding DEC dest,src Function DecrementDEC WRj,#short DIV dest,src Function Divide DIV R1,R5Binary Mode = A5Encoding Source Mode = Encoding Location ContentsDIV AB Djnz byte,rel-addrVariations Djnz dir8,rel Djnz 40H,LABEL1 Djnz 50H,LABEL2 Djnz 60H,LABELToggle CPL P1.7 Djnz R2,TOGGLE Djnz Rn,relEcall dest Function Ecall SubrtnEcall @DRk Binary Mode Source Mode Bytes States Encoding Ejmp dest FunctionEjmp Jmpadr Ejmp @DRk Binary Mode Source Mode Bytes States Encoding EretINC Byte Function Increment INC @R0 INC R0 ← a + INC dir8 Binary ModeDir8 ← dir8 + INC @Ri Binary Mode INC aINC Rn Binary Mode INC WRj,#short Binary ModeINC dest,src Function Increment WRj ← WRj + #short INC DptrVariations JB bit51,rel Binary Mode Source Mode JB bit51,rel JB bit,rel FunctionJB P1.2,LABEL1 JB ACC.2,LABEL2 Variations JBC bit51,rel Binary Mode Source Mode JBC bit51,rel JBC bit,relJBC ACC.3,LABEL1 JBC ACC.2,LABEL2 JC rel JBC bit,rel Binary Mode Source ModeHex Code in Binary Mode = Encoding Source Mode = Encoding Flags Example Bytes States EncodingJE rel Function JE LABEL1JG rel JG LABEL1 Bytes States Encoding Binary ModeSource Mode Not Taken JLE relJMP @A+DPTR JNB bit51,rel JNB bit,relVariations JNB bit51,rel Binary Mode Source Mode JNB P1.3,LABEL1 JNB ACC.3,LABEL2JNE rel JNC relJNC LABEL1 CPL CY JNC LABEL2 JNE LABEL1JNZ rel JNZ LABEL1 INC a JNZ LABEL2Jsge rel JSG relJSG LABEL1 Jsge LABEL1JSL rel JSL LABEL1Jsle rel Jsle LABEL1JZ rel Lcall dest Function Lcall addr16 Binary ModeJZ LABEL1 DEC a JZ LABEL2 Lcall SubrtnLjmp addr16 Binary Mode Lcall @WRj Binary Mode Source Mode Bytes States EncodingSource Mode = Encoding Operation Ljmp dest FunctionMOV A,#data Binary Mode Source Mode Bytes States Encoding LjmpPC ← addr.150 Operation MOV Ri ← #data MOV Rn,#data Binary ModeRn ← #data MOV dir8,dir8 Binary Mode MOVDir8 ← dir8 MOV dir8,@Ri Binary Mode Dir8 ← Ri MOV dir8,Rn Binary ModeDir8 ← Rn MOV @Ri,dir8 Binary Mode ← Ri MOV A,Rn Binary Mode MOV A,dir8 Binary Mode Source Mode Bytes States Encoding← dir8 MOV A,@Ri Binary Mode MOV Rn,dir8 Bytes States EncodingMOV dir8,A Binary Mode Source Mode Bytes States Encoding Dir8 ← a MOV @Ri,A Binary ModeMOV Rn,A Binary Mode Rmd ← Rms MOV WRjd,WRjs Binary Mode MOV DRkd,DRks Binary Mode Source Mode Bytes States EncodingMOV WRj,#data16 Binary Mode WRj ← #data16 #data hi #data low MOV Rm,dir16 Binary Mode Source Mode Bytes States Encoding MOV WRj,dir8 Binary Mode Source Mode Bytes States EncodingMOV DRk,dir8 Binary Mode Source Mode Bytes States Encoding MOV WRj,dir16 Binary ModeWRj ← dir16 MOV DRk,dir16 Binary Mode MOVMOV dir8,Rm Binary Mode Source Mode Bytes States Encoding MOV WRjd,@WRjs Binary ModeMOV WRj,@DRk Binary Mode MOV dir8,WRj Binary ModeDir8 ← WRj MOV dir8,DRk Binary Mode Dir8 ← DRk MOV dir16,Rm Binary ModeDir16 ← Rm MOV dir16,WRj Binary Mode MOV @WRj,Rm Binary Mode Source Mode Bytes4 States4 Encoding MOV @DRk,Rm Binary Mode Source Mode Bytes States EncodingMOV @WRjd,WRjs Binary Mode MOV @DRk,WRj Binary Mode Rm ← WRj + dis MOV WRj,@WRj + dis16 Binary ModeRm ← DRk + dis MOV WRj,@DRk + dis24 Binary Mode MOV @WRj + dis16,Rm Binary ModeMOV @WRj + dis16,WRj Binary Mode MOV @DRk + dis24,Rm Binary Mode MOV @DRk + dis24,WRj Binary ModeMOV dest-bit,src-bit Bit51 ← CY MOV CY,bit51 Binary Mode MOV bit,CY Binary Mode Source Mode Bytes StatesMOV P1.3,CY MOV CY,P3.3 MOV P1.2,CY MOV DPTR,#data16 MOV CY,bit Binary Mode Source Mode Bytes StatesBinary Mode Source Mode Bytes States Encoding MOV DPTR,#1234HMovc A,@A+PC Movc A,@A+base-reg FunctionRelpc INC Movc @A+PC RET Movc A,@A+DPTRVariations Movh DRk,#data16 Binary Mode Movh DRk,#data16Movs WRj,Rm Movs Movx dest,src FunctionMovx A,@DPTR ← Dptr Movx A,@Ri Binary ModeMovx A,@R1 Movx @R0,A MovxMovz WRj,Rm MovzMUL dest,src Function Multiply MUL R1,R0MUL WRjd,WRjs Binary Mode Source Mode Bytes States Encoding MUL ABBytes States Encoding Hex Code Operation NOPFunction Description Flags NOP Setb P2.7ORL A,#data Binary Mode Variations ORL dir8,A Binary Mode Source Mode Bytes StatesORL dir8,#data Binary Mode Source Mode Bytes States ORLORL A,Rn Binary Mode ORL A,dir8 Binary Mode Source Mode Bytes States Encoding← a V dir8 ORL A,@Ri Binary Mode ORL Rmd,Rms Binary ModeORL WRj,#data16 Binary Mode ORL WRjd,WRjs Binary Mode Source Mode Bytes States EncodingORL Rm,#data Binary Mode Source Mode Bytes States Encoding WRjd←WRjd V WRjsWRj ← WRj V dir8 ORL Rm,dir16 Binary Mode ORL Rm,dir8 Binary ModeORL WRj,dir8 Binary Mode Rm ← Rm V dir16 ORL WRj,dir16 Binary ModeWRj ← WRj V dir16 ORL Rm,@WRj Binary Mode Source Mode Bytes4 States3 EncodingRm ← Rm V WRj ORL Rm,@DRk Binary Mode ORL CY,src-bitORL CY,/bit51 Binary Mode Source Mode Bytes States ORL CY,bit Binary Mode Source Mode Bytes StatesPOP src Function ORL CY,/bit Binary Mode Source Mode Bytes StatesPOP dir8 Binary Mode POP DPH POP DPLPOP Rm Binary Mode POP WRj Binary ModePOP DRk Binary Mode Push DPL Push DPH Push #data Binary ModePush dest Function Operation PushPush #data16 Binary Mode Push WRj Binary ModeRET Operation RETReti FlagsRL a RL aRLC a RR a Example Bytes States EncodingRLC a RR aRRC a RRC aFlags Example Bytes States Encoding Hex Code Operation Setb bit Function Set bitSetb Setb CYSLL Rm Binary Mode Sjmp ReladrSLL src SRA src SRASRA WRj Binary Mode Source Mode Bytes States Encoding SRL srcVariations SUB Rmd,Rms Binary Mode SUB dest,src Function SubtractSUB R1,R0 DRkd ← DRkd DRks SUB DRkd,DRks Binary Mode Source Mode Bytes States EncodingSUB SUB WRj,#data16Hex Code Binary Mode = A5Encoding SUB DRk,#data16 Binary ModeSUB Rm,dir8 Binary Mode Source Mode Bytes States SUB WRj,dir8 Binary ModeRm ← Rm WRj SUB Rm,@DRk Binary Mode Rm ← Rm dir16 SUB WRj,dir16 Binary ModeSUB Rm,@WRj Binary Mode Source Mode Bytes4 States3 Encoding SUB Rm,dir16Variations Subb A,#data Binary Mode Subb A,src-byte FunctionSubb A,R2 Subb Swap a Swap aTrap Binary Mode = Encoding Source Mode = Encoding XCH A,byteXCH A,@R0 XCH A,Rn Bytes States Encoding XCH A,@Ri Binary Mode Source Mode Bytes States EncodingOperation XCH Xchd A,@Ri FunctionXRL dir8,A Binary Mode Source Mode Bytes States XRL A,R0Dir8 ← dir8 ∀ a XRL A,dir8 Binary Mode Source Mode Bytes States EncodingXRL XRL A,#dataXRL A,Rn XRL WRjd,WRjsXRL Rm,dir8 XRL Rm,#dataXRL WRj,#data16 XRL WRj,dir8WRj ← WRj ∀ dir8 XRL Rm,dir16 Binary Mode \XRL WRj,dir16XRL Rm,@Wrj XRL Rm,@Drk Binary Mode Page Signal Descriptions Page 8XC251SP 8XC251SA8XC251SB 8XC251SQPlcc DIP Power & Ground NameAddress & Data Name Processor Control Name8XC251SP 8XC251SQ Component As mounted On PC boardCEX20 PWR DIPGND DIP WAIT# WclkTable B-3. Memory Signal Selections RD10 RD10 P1.7/CEX P3.7/RD#/A16Page Registers Page Appendix C Registers Table C-1 XC251SA, SB, SP, SQ SFR Map CCAP0H CCAP1H CCAP2H CCAP3H CCAP4HTable C-2. Core SFRs Table C-3. I/O Port SFRsTable C-5. Timer/Counter and Watchdog Timer SFRs Table C-4 Serial I/O SFRsSB9H Table C-6. Programmable Counter Array PCA SFRs CconTable C-7. Register File Mnemonic AddressACC F0HCCAP2H,L SFCH, Sech CCAPxH, CCAPxL x =CCAP1H,L SFBH, Sebh CCAP3H,L SFDH, SedhCCAPM3 Sddh CCAPM1 SdbhCCAPM2 Sdch CCAPM4 SdehCH, CL SF9H SE9HCmod Cidl Wdte CPS1 CPS0 ECFDPH DPLDpxl Global Interrupt Enable IPH0 IPH0 IPL0 Priority LevelIPL0 P0 Contents P1 ContentsP1.70 Port 1 Register P2 Contents P3 ContentsP3.70 Port 3 Register Pcon SMOD1 SMOD0 POF GF1 GF0 IDLSee -10 on RCAP2H, RCAP2L RCAP2L ScahSaddr Slave Individual AddressSADDR.70 Data Sent/Received by Serial I/O Port SadenSbuf SBUF.70Scon FE/SM0 SM1 SM2 REN TB8 RB8SP Contents SP.70 Stack PointerSPH Contents SPHSPH.70 Stack Pointer High T2CON TF2 EXF2 Rclk Tclk EXEN2 TR2Xxxx XX00B T2OE DcenTcon TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0Address S89H Reset State TL0 S8AH TH0, TL0TH0 S8CH TH1, TL1TL2 Scch TH2, TL2TH2 Scdh Rtwce RtweWdtrst Contents Write-only WdtrstWDTRST.70 Page Glossary Page Glossary Dptr Eprom LSB Otprom Uart Word Page Index Page Index Index-2 Index-3 Index-4 Index-5 Index-6 Index-7 Index-8 Index-9