Overview of Math Coprocessing | Intel 80C188XL, 80C186XL instruction

CHAPTER 11

MATH COPROCESSING

The 80C186 Modular Core Family meets the need for a general-purpose embedded microproces- sor. In most data control applications, efficient data movement and control instructions are fore- most and arithmetic performed on the data is simple. However, some applications do require more powerful arithmetic instructions and more complex data types than those provided by the 80C186 Modular Core.

11.1 OVERVIEW OF MATH COPROCESSING

Applications needing advanced mathematics capabilities have the following characteristics.

•Numeric data values are non-integral or vary over a wide range

•Algorithms produce very large or very small intermediate results

•Computations must be precise (i.e., calculations must retain several significant digits)

•Computations must be reliable without dependence on programmed algorithms

•Overall math performance exceeds that afforded by a general-purpose processor and software alone

For the 80C186 Modular Core family, the 80C187 math coprocessor satisfies the need for pow- erful mathematics. The 80C187 can increase the math performance of the microprocessor system by 50 to 100 times.

11.2 AVAILABILITY OF MATH COPROCESSING

The 80C186 Modular Core supports the 80C187 with a hardware interface under microcode con- trol. However, not all proliferations support the 80C187. Some package types have insufficient leads to support the required external handshaking requirements. The 3-volt versions of the pro- cessor do not specify math coprocessing because the 80C187 has only a 5-volt rating. Please refer to the current data sheets for details.

To execute numerics instructions, the 80C186XL must exit reset in Enhanced Mode. The pro- cessor checks its TEST pin at reset and automatically enters Enhanced Mode if the math copro- cessor is present.

11-1

Image 286

$Intel 80C188XL, 80C186XL user manual Overview of Math Coprocessing, Availability of Math Coprocessing$

Contents

80C186XL/80C188XL Microprocessor User’s Manual 80C186XL/80C188XL Microprocessor User’s Manual Intel Corporation Contents Contents Clock Generation Setting the PCB Base LocationPower Management LCS Chapter Refresh Control Unit Programming the Interrupt Control Unit Functional Overview Programming the TIMER/COUNTER UnitFunctional Overview Chapter Math Coprocessing Chapter Once Mode Figures Reset Configuration UCS Interrupt Control Register for Noncascadable External Pins 10-9 Tables Flag Bit Functions Examples Example Introduction Page Chapter Introduction Feature 80C186XL 80C186EA 80C186EB 80C186EC HOW to USE this ManualComparison of 80C186 Modular Core Family Products Related Documents and Software Related DocumentsDocument/Software Title Order No FaxBack Service Electronic Support Systems Bulletin Board System BBS World Wide Web CompuServe ForumsTechnical Support Product Literature Training ClassesPage Overview 80C186 Family Architecture Page Chapter Overview of the 80C186 Family Architecture Architectural Overview Simplified Functional Block Diagram of the 80C186 Family CPU Execution Unit Bus Interface Unit Physical Address Generation General Registers General Registers Implicit Use of General Registers Segment RegistersOperations Instruction Pointer Segment Registers Flags Memory Segmentation PSW Flags Register NameRegister Mnemonic Register Function Logical Addresses Segment Locations in Physical Memory Data DS Code CS Stack SS Extra ES Fffffh 2BFH 2BEH 2BDH 2BCH 2BBH 2BAH Dynamically Relocatable Code Type of Memory Reference Default Alternate OffsetLogical Address Sources Segment Code Data Before After Relocation Code SegmentSegment Data Extra Stack Implementation Reserved Memory and I/O Space 10. Stack Operation Software Overview Instruction Set General-Purpose Data Transfer InstructionsInput/Output Pushf Popf U U O D I T S Z U a U P U C Lahf S Z U a U P U CSahf 7 6 5 4 3 2 1 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Multiplication AdditionSubtraction Division Hex Bit Pattern Unsigned Signed Unpacked Packed Binary Arithmetic Interpretation of 8-Bit NumbersBit Manipulation Instructions Shifts String Instructions Program Transfer Instructions String Instruction Register and Flag UseCX AL/AX Overview of the 80C186 Family Architecture Iteration Control Conditional TransfersUnconditional Transfers Interrupts 10. Interpretation of Conditional Transfers Mnemonic Condition Tested Jump if… 11. Processor Control Instructions Addressing ModesProcessor Control Instructions Register and Immediate Operand Addressing Modes Memory Addressing Modes 0000 Physical Addr BIU Opcode Mod R/M Displacement 13. Direct Addressing 14. Register Indirect Addressing 15. Based Addressing Base Register Displacement High Address Rate AgeRate Base Vac Register Dept Div Employee Age 18. Accessing an Array with Indexed Addressing 17. Indexed Addressing 19. Based Index Addressing 20. Accessing a Stacked Array with Based Index Addressing Opcode Source EA Destination EA Type Description Data Types Used in the 80C186 Modular Core Family12. Supported Data Types BCD 23 C186 Modular Core Family Supported Data Types Interrupts and Exception Handling Interrupt/Exception Processing 3FE 3FC Overview of the 80C186 Family Architecture PSW Interrupt Enable BitStack Trap Flag Maskable Interrupts Exceptions Invalid Opcode Type Software Interrupts Interrupt Latency Total Interrupt Response TimeClocks Interrupt and Exception Priority NMI Execute Divide Service RoutineIret Trap Flag = ??? 29. Simultaneous NMI and Single Step Interrupts Interrupt Enable Bit IE = Trap Flag TF = 30. Simultaneous NMI, Single Step and Maskable InterruptPage Bus Interface Unit Page Address and Data BUS Concepts Multiplexed Address and Data BUS1 16-Bit Data Bus Fffff Ffffe Ffffd Ffffc Physical Implementation Address Space forMByte KBytes A190 D70 A191 D158 Odd Byte Transfer Even Byte TransferA191 D158 BHE High D70 A0 Low A191 D158 BHE High A191 D158 BHE Low D70 A0 Low Bit Data Bus Even Word Transfers Second Bus Cycle First Bus CycleA191 D158 BHE Low D70 A0 High A191 D158 BHE Low Memory and I/O Interfaces Bit Data Bus Word Transfers 2 8-Bit Bus Memory and I/O Requirements 1 16-Bit Bus Memory and I/O RequirementsBUS Cycle Operation Clkout ALE PhaseLow Phase High Phase S20 Valid Status AD150 Address Data Hold Deasserted Bus ReadyRequest Pending RES# Or TI Address Status Phase Or TW Or TI Data PhaseAddress/Status Phase Clkout A1916 S20 STB ALE STB Data Phase Wait States Clkout RD/ WR Or TW Or TIAD150 Valid Write Data Read Read Data S20 Ardy Clkout Srdy ReadyBUS Ready CS1 CS2 CS3 CS4 ALE Clkout 16. Generating a Normally Ready Bus Signal Clock Clkout Ardy Srdy Idle States 18. Normally Ready System Timings Read Bus Cycle Types BUS CyclesRead Bus Cycles Read Cycle Critical Timing Parameters A150 A158Rfsh DT/R DEN 27C256 UCSAD70 O0-7 LA151 AD158 Write Bus Cycle Types A158 A150Status Bits Bus Cycle Type A014 O18 CS1 AD70 AD158 LA151LA0 BHE LCS Interrupt Acknowledge Bus Cycle Write Cycle Critical Timing Parameters Lock DT/R DEN INTA0 INTA1BHE RD, WR INTA0 Inta INT0 IR0 IR7 PCS0 LA1 Processor 82C59ASystem Design Considerations Halt Bus Cycle Rfsh = Pins Pin State011 AD150 AD70 A158 A1916 BHE AD150 AD70 A158 A1916 Temporarily Exiting the Halt Bus StateClkout Hold Hlda Control S20 AD150 AD70 A158 A1916 BHE Rfsh AD70 A158 T4 T1 T2 T3T3 TI TI TI TI RFSH=1 NMI/INTx System Design Alternatives Buffering the Data Bus Clkout RD,WR DT/R DEN DT/ R DeviceCPU Local Bus Buffered Bus Buffer Local Data Bus MCS0Buffer Buffered Data Bus AD70 Synchronizing Software and Hardware Events Using a Locked Bus Queue Status Using the Queue Status SignalsQueue Status Signal Decoding No queue operation occurred MULTI-MASTER BUS System Designs Entering Bus Hold RD, W R Float BHE , S20 Signal Hold ConditionFloat Lock Refresh Operation During a Bus Hold BHE, S20 Clkout Hold Hlda DEN RD, WRDT/R Lock Latched Hlda Hlda Reset Hold PRE CLRExiting Hold DT/R, S20 A1916, Lock DEN RD, WR, BHEBUS Cycle Priorities BUS Interface Unit Page Peripheral Control Block Page Peripheral Control Registers PCB Relocation Register Register Name PCB Relocation Register Register Mnemonic Bit Bit Name Reset Function Mnemonic StateRelreg Peripheral Control Block Reserved Locations Accessing the Peripheral Control BlockReady Signals and Wait States Bus Cycles Bus Operation Word reads Accessing Reserved Locations Setting the PCB Base LocationAccessing the Peripheral Control Registers Writing the PCB Relocation Register Considerations for the 80C187 Math Coprocessor Interface Page Clock Generation Power Management Page RES Clock GenerationCrystal Oscillator = Inverter Output Z 90˚ 180˚ Oscillator Operation Crystal Connections to Microprocessor Third-Overtone Crystal Inductor L1 Values µH Selecting Crystals Reset and Clock Synchronization Using an External OscillatorOutput from the Clock Generator Typical Ct = V 1 e 1µf typical Cold Reset Waveform PCS60,NCS Clkout Power Management Clkout ResetRES Resync Power-Save Mode Entering Power-Save Mode Register Name Register Mnemonic Register Function Power Save RegisterEnables and sets clock division factor Pwrsav 10. Power-Save Clock Transition Leaving Power-Save Mode Example Power-Save Initialization Code Syntax Chip-Select Unit Page CHIP-SELECT Unit Features and Benefits Common Methods for Generating CHIP-SELECTS 27C256 Chip-Selects Using Addresses Directly Simple DecoderCHIP-SELECT Unit Functional Overview 74AC138 MCS1 MCS3MCS2 PCS1 A1916 UCS, PC S60 MCS30, LCS Data Active For Top 1 KByte Memory Map 1AddressSrdy Ardy UCS 1MB Chip-Select Unit Registers ProgrammingInitialization Sequence Control Register Alternate Register Umcs UCS Control RegisterControls the operation Chip-select LCS Control Register Lmcs Controls the operation Chip-selects MCS Control RegisterMmcs MCS Pacs PCS Control RegisterPCS Mpcs Register NameMCS and PCS Alternate Control RegisterX S UCS Block Size and Starting Address Programming the Active RangesUCS Active Range Umcs Field Block Size Starting Address U1710 MCS Active Range LCS Active RangeLCS Active Range Lmcs Field Block Size Ending Address U1710 MCS Block Size and Start Address Restrictions Block Size Mmcs Start Address Kbytes Restrictions Bus Wait State and Ready Control PCS Active Range Wait State Ready R2 Control Bit Wait Wait State Value R10 State CounterOverlapping Chip-Selects Memory or I/O Bus Cycle Decoding Programming Considerations CHIP-SELECTS and BUS Hold Example 1 Typical System ConfigurationExamples 13. Typical System Example 6-1. Initializing the Chip-Select Unit MOD186XREF Name CSUEXAMPLE1 Drambase EQU Place memory variables here Refresh Control Unit Page CPU CLR REQ Refresh Control Unit Capabilities Role of the Refresh Control UnitRefresh Control Unit Operation Refresh Control Unit Operation Flow Chart Refresh Addresses Refresh Address Formation Identification of Refresh Bus Cycles Refresh BUS CyclesGuidelines for Designing Dram Controllers Data Bus Width Muxed Row Column Address S20 T3/TW ClkoutRAS CAS Calculating the Refresh Interval Programming the Refresh Control UnitRefresh Control Unit Registers Register FunctionDetermines upper 7 bits of refresh address Register NameRefresh Base Address RegisterRfbase Refresh Base Address Register Rftime Register Function Sets refresh rate Controls Refresh Unit operation Refresh Control RegisterRfcon Programming Example Example 7-1. Initializing the Refresh Control Unit Refresh Operation and BUS Hold Clkout Hold Hlda DEN RD, WR BHE, S2 DT / R A1916Page Interrupt Control Unit Page Chapter Interrupt Control Unit Functional Overview Generic Functions in Master Mode Master ModeTimer 0 Timer 1 Timer DMA Interrupt Priority Default Interrupt PrioritiesInterrupt Masking Interrupt Name Relative Priority Interrupt Nesting Priority Resolution Functional Operation in Master ModeTypical Interrupt Sequence Priority Resolution Example Cascading with External 8259As Interrupts That Share a Single Source INT INT1 INT INT0Inta INTA0 Inta INTA1 Fixed Interrupt Types Interrupt Acknowledge SequencePolling Interrupt Name Interrupt Type Edge and Level Triggering Additional Latency and Response Time Read CS Idle Push Flags Push CS Push IP Inta IdleInta Idle Read IP Programming the Interrupt Control Unit 2CH Interrupt Control Registers2AH Interrupt Control Register for Internal Sources MSK I2CON, I3CON Register NameInterrupt Control Register non-cascadable pinsLVL Sfnm Register NameInterrupt Control Register cascadable pinsI0CON, I1CON CAS Reqst Interrupt Request RegisterRegister Name Interrupt Request Register Register Mnemonic Register Function Stores pending interrupt requests Register Function Masks individual interrupt sources Register Name Interrupt Mask Register Register MnemonicImask Priority Mask Register Primsk In-Service RegisterPriority Mask Register Masks lower-priority interrupt sources Indicates which interrupt handlers are in process In-Service RegisterInserv Poll and Poll Status Registers Poll Poll RegisterIreq Pollsts Read to check for pending interrupts when pollingPoll Status Register End-of-Interrupt EOI Register EOI Used to issue an EOI commandEnd-of-Interrupt Register Interrupt Status Register Intsts Slave ModeInterrupt Status Register Dhlt INT0 Inta IRQ INT VCC Slave Mode Programming 16. Interrupt Sources in Slave Mode Interrupt Vector Register Slave Mode Fixed Interrupt Type BitsMaster Mode Slave Mode PCB Offset Register Name Interrupt Control Unit Register Comparison Register NameInterrupt Vector Register Slave Mode only Intvec End-of-Interrupt Register in Slave Mode Used to issue the EOI command Inta INTA0 Select Lock Interrupt Vectoring in Slave ModeT1 T2 T3 T4 CAS20 Slave Cascade Address From 8259A Initializing the Interrupt Control Unit for Master Mode Inta Idle Read IP Read CS Push Flags Push CS Push IP Priorities are used Page Timer/Counter Unit Page Chapter TIMER/COUNTER Unit Timer Element Registers Output Latch Interrupt Latch Clock Counter Element Multiplexing and Timer Input Synchronization T0IN T1IN T0OUT T1OUT Timers 0 and 1 Flow Chart From Programming the TIMER/COUNTER Unit Timer/Counter Unit Output Modes Defines Timer 0 and 1 operation Timer 0 and 1 Control RegistersT0CON, T1CON ALT RTGEXT Cont T2CON Timer 2 Control RegisterDefines Timer 2 operation Maximum count. The MC bit must be cleared T0CNT, T1CNT, T2CNT Register Name Timer Count Register Register MnemonicRegister Function Contains the current timer count C C Timer Maxcount Compare Registers Counting Modes Timer 0 and 1 Clock SourcesClock Sources Clock Source Retriggering Timer Operation Timer RetriggeringPulsed and Variable Duty Cycle Output Timer Serviced Internal Count Value Maxcount TxOUT Pin Enabling/Disabling Counters Input Setup and Hold Timings Timer InterruptsTiming Real-Time Clock Timer/Counter Unit Application ExamplesSynchronization and Maximum Frequency Square-Wave Generator Example 9-1. Configuring a Real-Time Clock Intsts Out Dx, al Timer2interruptroutine proc far Example 9-2. Configuring a Square-Wave Generator T1CON Example 9-3. Configuring a Digital One-Shot Cmpb Page Direct Memory Access Unit Page Chapter Direct Memory Access Unit DMA Transfer Fetch Deposit Typical DMA Transfer DMA Transfer Directions Source and Destination PointersDMA Requests Byte and Word Transfers Cycle External RequestsT1 or T2 or T3 or TW or T4 or DRQ DRQ Case Source Synchronization Clkout DRQ Timer 2-Initiated TransfersFetch Cycle Deposit Cycle T1 T2 T3 T4 T1 T2 T3 T4 TI TI Case DMA Transfer Counts Termination and Suspension of DMA Transfers Two-Channel DMA Unit DMA Unit InterruptsDMA Cycles and the BIU DMA Channel Arbitration Module Two-Channel DMA Module Programming the DMA Unit SRCDMA Channel Parameters Register Mnemonic DxSRCH Register NameDMA Source Address Pointer HighDMA Xxxxh Register Mnemonic DxSRCL Register NameDMA Source Address Pointer LowS S a a DxDSTH Register NameDMA Destination Address Pointer HighContains the upper 4 bits of the DMA Destination pointer Register NameDMA Destination Address Pointer Low Register Mnemonic DxDSTL Ddec D I E N C C C N TDmem Dinc Synchronization Type Idrq Strt CHGWord Selecting Channel Synchronization Arming the DMA ChannelProgramming the Transfer Count Options Setting the Relative Priority of a Channel Generating Interrupts on Terminal Count Hardware Considerations and the DMA Unit Suspension of DMA TransfersInitializing the DMA Unit DRQ Pin Timing Requirements DMA Latency DMA Transfer Rates Generating a DMA Acknowledge DMA Unit Examples Example 10-1. Initializing the DMA Unit MOV DS, AX Assume Dsdataseg 10-24 10-25 Example 10-2. Timed DMA Transfers 10-27 Page Math Coprocessing Page Overview of Math Coprocessing Availability of Math Coprocessing 80C187 Math Coprocessor 11.3.1 80C187 Instruction Set Integer Transfers C187 Data Transfer InstructionsReal Transfers Packed Decimal Transfers C187 Arithmetic Instructions Other Operations Transcendental Instructions Comparison InstructionsC187 Comparison Instructions C187 Transcendental Instructions C187 Processor Control Instructions Constant InstructionsC187 Constant Instructions Fldz FLD1 Fldpi FLDL2T FLDL2E FLDLG2 FLDLN2 11.3.2 80C187 Data Types Microprocessor and Coprocessor Operation C187-Supported Data Types Modular Core 80C18780C186 C187 I/O Port Assignments Processor Bus Cycles Accessing the 80C187Clocking the 80C187 Address Read Definition Write Definition System Design Tips C187 Configuration with a Partially Buffered Bus Exception Trapping Example Math Coprocessor Routines 80C186 Modular Core C187 Exception Trapping via Processor Interrupt Pin Name Example80C187init Example 11-2. Floating Point Math Routine Using Fsincos Results Once Mode Page Chapter Once Mode ENTERING/LEAVING Once Mode RES UCS LCS Oscout 80C186 Instruction Set Additions Extensions Page 80C186 Instruction SET Additions Data Transfer Instructions String Instructions High-Level Instructions Figure A-1. Formal Definition of Enter Figure A-2. Variable Access in Nested Procedures Figure A-4. Stack Frame for Procedure a at Level BPM BPA BPB Leave Bound register, address 80C186 Instruction SET Enhancements Bit Manipulation Instructions Arithmetic InstructionsShift Instructions ROL destination, count Rotate Instructions Input Synchronization Page WHY Synchronizers are Required Figure B-1. Input Synchronization Circuit Asynchronous Pins Instruction Set Descriptions Page Table C-1. Instruction Format Variables Variable Description Table C-2. Instruction Operands Operand Description Table C-3. Flag Bit Functions Table C-4. Instruction Set ADC Ascii Adjust for SubtractionAAS Add with Carry Logical ADDADD dest, src Dest, src Bound Call ProcedureCall procedure-name Detect Value Out of Range Clear Carry flag Convert Byte to WordClear Direction flag Clear Interrupt-enable Flag Complement Carry Flag CMP dest, src CMPCompare Compare String Decimal Adjust for Subtraction Decimal Adjust for AdditionConvert Word to Doubleword DEC Decrement Divide When Source Operand is a Byte When Source Operand is a Word Enter locals, levels Procedure EntryEscape Halt Integer Divide When Source Operand is a Byte Imul Integer Multiply When Source Operand is a ByteInput Byte or Word When Source Operand is a Byte Accum, port String INCIncrement INS dest-string, port Interrupt INT interrupt-type Jump on Above Interrupt on OverflowInterrupt Return Jump on Not Below or Equal Jump on Below Jump on Above or EqualJump on Not Below Jump on Not Above or Equal Jump on Greater Than Jump if CX ZeroJump on Equal Jump on Zero Jump on Not Less Than or Equal Jump on Less Than or Equal Name Description Operation Flags Affected Jump on Less ThanJump on Not Greater Than or Equal Jump on Not Greater Than Jump on Not Overflow Jump on Not EqualJump on Not Zero Jump on Not Sign Jump on Parity Equal Name Description Operation Flags Affected Jump on OverflowJump on Parity Instruction Format Load Effective Address Load Pointer Using DSLDS dest, src LEA dest, src LES dest, src Load Pointer Using ESLock the Bus Loop Load String Byte or Word When Source Operand is a ByteLods src-string Loop While Equal Move Byte or Word Loop While Not EqualLoop While Not Zero MOV dest, src Movs dest-string, src-string Multiply When Source Operand is a ByteMove String MUL Logical Not When Source Operand is a Byte Negate When Source Operand is a ByteNEG Output Name Description Operation Flags Affected Logical orOr dest,src OUT port, accumulator Outs port, srcstring Out StringPop Pop Flags Pop AllPush Push All Push Flags Rotate Through Carry Right Rotate Through Carry LeftRCL dest, count RCR dest, count Repeat While Zero RepeatRepeat While Equal Repeat While Not Equal RET optional-pop-value RETReturn Rotate Left ROR dest, count Rotate RightStore Register AH Into Flags Shift Arithmetic Left Shift Logical LeftShift Arithmetic Right Subtract With Borrow SBBSBB dest, src Scan String When Source Operand is a Byte Scas dest-string Set Carry Flag Shift Logical RightSHR dest, src Set Direction Flag Store Byte or Word String When Source Operand is a Byte Set Interrupt-enable FlagStos dest-string SUB dest, src SUBSubtract Test Exchange WaitXchg dest, src Exclusive Or TranslateXlat translate-table XOR dest, srcPage Instruction Set Opcodes and Clock Cycles Page Mod Effect on EA Calculation Table D-1. Operand VariablesEA Calculation Reg Bit w=1 Bit w=0 Table D-2. Instruction Set Summary Function Format Clocks Arithmetic Instructions Arithmetic Instructions BIT Manipulation Instructions String Manipulation Instructions JB/JNAE = LOOPNZ/LOOPNE = Table D-3. Machine Instruction Decoding Guide Processor Control Instructions Instruction SET Opcodes and Clock Cycles Instruction SET Opcodes and Clock Cycles Instruction SET Opcodes and Clock Cycles Instruction SET Opcodes and Clock Cycles AX,CX Instruction SET Opcodes and Clock Cycles Instruction SET Opcodes and Clock Cycles Instruction SET Opcodes and Clock Cycles AL,DX Instruction SET Opcodes and Clock Cycles Table D-4. Mnemonic Encoding Matrix Left Half Table D-4. Mnemonic Encoding Matrix Right Half Table D-5. Abbreviations for Mnemonic Encoding Matrix Abbr Definition Index Page Index Index-2 Index-3 Index-4 Index-5 Index-6 Index-7 Index-8