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Xilinx UG129 manual Figure C-11ZERO Flag Logic for Test Instruction

Models: UG129

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Appendix : PicoBlaze Instruction Set and Event Reference

TEST sX, Operand — Test Bit Location in Register sX, Generate Odd Parity

The TEST instruction performs two related but separate operations. The ZERO flag indicates the result of a bitwise logical AND operation between register sX and the specified Operand. The ZERO flag is set if the resulting bitwise AND is zero, as shown in Figure C-11. The CARRY flag indicates the XOR of the result, as shown in Figure C-12, which behaves like an odd parity generator.

Register sY Literal kk

7

6

5 4 3

2

1

0

Register sX

7

6

5

4

3

2

1

0

Bitwise AND

If all bit results are zero, set ZERO flag.

ZERO

UG129_c3_03_051404

Figure C-11:ZERO Flag Logic for TEST Instruction

Register sY
Register sY	7						6							5						4						3						2						1							0
Literal kk	7						6							5						4						3						2						1							0
Literal kk

Register sX				7							6							5						4					3						2							1

Mask out unwanted bits. 0=mask bit, 1=include bit

0

Generate odd parity (XOR) from bit results.

CARRY

UG129_c3_04_051404

Figure C-12:CARRY Flag Logic for TEST Instruction

Examples

TEST sX, sY ; Test register sX using register sY as the test mask TEST sX, kk ; Test register sX using the immediate constant kk as the

; test mask

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		UG129 (v1.1.2) June 24, 2008

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Xilinx UG129 manual Figure C-11ZERO Flag Logic for Test Instruction

Contents

PicoBlaze 8-bit Embedded Microcontroller User Guide UG129 v1.1.2 June 24Revision History Version RevisionLimited Warranty and Disclaimer LimitationsLimitation of Liability Technical Support LimitationsAcknowledgments Preface AcknowledgmentsGuide Contents About This GuidePreface About This Guide Table of Contents Interrupts Performance Appendix C PicoBlaze Instruction Set and Event Reference PicoBlaze Microcontroller Features IntroductionPicoBlaze Microcontroller Functional Blocks General-Purpose RegistersInstruction Program Store IntroductionArithmetic Logic Unit ALU FlagsByte Scratchpad RAM Input/OutputReset Program Counter PCProgram Flow Control CALL/RETURN StackWhy the PicoBlaze Microcontroller? Why the PicoBlaze Microcontroller?Why Use a Microcontroller within an FPGA? Strengths WeaknessesSignal Direction Description PicoBlaze Interface SignalsPicoBlaze Interface Signal Descriptions Readstrobe PicoBlaze Instruction Set 1PicoBlaze Instruction Set alphabetical listingEnable Interrupt Returni Disable Address Spaces Instruction 1Kx18 Direct PicoBlaze Instruction Set Processing DataLogic Instructions 2Complementing a Register Value 3Inverting an Individual Bit Location616-Setting a Bit Location Arithmetic InstructionsSUB and Subcy Subtract Instructions Multiplication 10Incrementing and Decrementing a Register148-bit by 8-bit Multiply Routine Produces a 16-bit Product 168-bit by 8-bit Multiply Routine Using Hardware Multiplier DivisionNo Operation NOP 18Loading a Register with Itself Acts as a NOP InstructionSetting and Clearing Carry Flag Test and Compare22The Test Instruction Affects the Zero Flag 25Generate Parity for a Register Using the Test Instruction Shift and Rotate InstructionsSRX 5PicoBlaze Rotate Instructions Rotate Left Rotate RightMoving Data Program Flow ControlProgram Flow Control 6Instruction Conditional Execution DescriptionCALL/RETURN Program Flow Control UG129 v1.1.2 June 24 Interrupts 1Simple Interrupt LogicExample Interrupt Flow 2Example Interrupt Flow3Interrupt Timing Diagram Example Interrupt FlowInterrupts Scratchpad RAM Address ModesDirect Addressing Indirect AddressingImplementing a Look-Up Table Scratchpad RAMStack Operations Stack OperationsFifo Operations Scratchpad RAM Input and Output Ports Portid PortInput Operations 1INPUT Operation and Fpga Interface LogicInput Operations PORTID70INPORT70 Register s0Input and Output Ports Applications with Few Input SourcesReadstrobe Interaction with FIFOs Output Operations Output OperationsSimple Output Structure for Few Output Destinations Fpga Register8Use Constant Directives to Declare Output Port Addresses Pipelining for Maximum Performance 9Pipelining the Portid Decoding Improves PerformancePipelining for Maximum Performance Repartitioning the Design for Maximum Performance Effective Pipelining Improves Read PerformanceInstruction Storage Configurations Standard Configuration Single 1Kx18 Block RAMInstruction Storage Configurations Two PicoBlaze Microcontrollers Share a 1Kx18 Code Image6Using Distributed ROM for Instruction Memory Distributed ROM Instead of Block RAMInstruction Storage Configurations Performance Input Clock FrequencyPredicting Executing Performance FrequencyPerformance PicoBlaze Development Tools AssemblerPicoBlaze Development Tools Assembly ErrorsInput and Output Files Configuring pBlazIDE for the PicoBlaze Microcontroller Mediatronix pBlazIDEImporting KCPSM3 Code into pBlazIDE 4Example of How Kcpsm Source Code Converts to pBlazIDE CodeDifferences Between the KCPSM3 Assembler and pBlazIDE DirectivesDifferences Between the KCPSM3 Assembler and pBlazIDE Function KCPSM3 Directive PBlazIDE DirectivePicoBlaze Development Tools KCPSM3 Module Using the PicoBlaze Microcontroller in an Fpga DesignVhdl Design Flow Connecting the Program ROM Using the PicoBlaze Microcontroller in an Fpga DesignBlack Box Instantiation of KCPSM3 using KCPSM3.ngc Generating the Program ROM using progrom.coeGenerating an ESC Schematic Symbol Black Box Instantiation of KCPSM3 using KCPSM3.ngcUsing the PicoBlaze Microcontroller in an Fpga Design Naming or Aliasing Registers Assembler DirectivesLocating Code at a Specific Address Defining Constants Naming the Program ROM Output FileDefining I/O Ports pBlazIDE PBlazIDEDefining I/O Ports pBlazIDE Input PortsOutput Ports Input/Output Ports 5Example of pBlazIDE Dsout DirectiveCustom Instruction Op-Codes Custom Instruction Op-CodesAssembler Directives Simulating PicoBlaze Code Instruction Set Simulation with pBlazIDE Simulator Control Buttons Instruction Set Simulation with pBlazIDE2pBlazIDE Simulator Control Buttons Function Assemble EditRun Step OverRun to Cursor PauseTurbocharging Simulation using FPGAs Turbocharging Simulation using FPGAsSimulating PicoBlaze Code Related Materials and References Chapter Related Materials and References Example Program Templates KCPSM3 SyntaxPBlazIDE Syntax Appendix Example Program TemplatesPicoBlaze Instruction Set and Event Reference ADD sX, Operand -Add Operand to Register sXAddcy sX, Operand -Add Operand to Register sX with Carry Appendix PicoBlaze Instruction Set and Event ReferenceSX, Operand Logical Bitwise and Register sX with Operand SX, Operand Logical Bitwise and Register sX with OperandExamples Condition Table C-1CALL Instruction Conditions DescriptionCompare sX, Operand Compare Operand with Register sX Figure C-4COMPARE OperationDisable Interrupt Disable External Interrupt Input Disable Interrupt Disable External Interrupt InputEnable Interrupt Enable External Interrupt Input Figure C-5FETCH Operation KCPSM3 Instruction PBlazIDE InstructionPortid Å Operand SX Å Inport PC Å PC + Interrupt Event, When Enabled Table C-2JUMP Instruction Conditions Description Load sX, Operand Load Register sX with Operand Or sX, Operand Logical Bitwise or Register sX with Operand Or sX, Operand Logical Bitwise or Register sX with OperandFigure C-7OUTPUT Operation and Fpga Interface Logic Table C-3PicoBlaze Reset Values Resource Reset Event Effect Reset EventReset Event Table C-4RETURN Instruction Conditions Description PBlazIDE Equivalent RET, RET C, RET NC, RET Z, RET NZ RL sX Rotate Left Register sX RR sX Rotate Right Register sXTable C-5Rotate Left RL Operation Table C-6Rotate Right RR OperationTable C-7Shift Left Operations SL 0 1 X a sX Shift Left Register sXSL 0 1 X a sX Shift Left Register sX SR 0 1 X a sX Shift Right Register sX Shift Right with ‘ 0’ fill Figure C-8STORE Operation SUB sX, Operand -Subtract Operand from Register sX Store sX, sYFigure C-10SUBCY Instruction Registers sX Flags CARRY, Zero PBlazIDE Equivalent Subc Figure C-11ZERO Flag Logic for Test Instruction PicoBlaze 8-bit Embedded Microcontroller 117 XOR sX, Operand Logical Bitwise XOR Register sX with Operand Instruction Codes Table D-1PicoBlaze Instruction CodesJump Z PicoBlaze 8-bit Embedded Microcontroller 121 Appendix Instruction Codes Reg Description Register and Scratchpad RAM Planning WorksheetsRegisters Loc Description Scratchpad RAMAppendix Register and Scratchpad RAM Planning Worksheets