avrora.core
Class Instr

java.lang.Object
  avrora.core.Instr

All Implemented Interfaces:

InstrPrototype

Direct Known Subclasses:

Instr.IMM_class, Instr.IMMIMM_class, Instr.IMMREG_class, Instr.IMMWORD_class, Instr.NONE_class, Instr.REG_class, Instr.REGIMM_class, Instr.REGIMMREG_class, Instr.REGREG_class, Instr.REGREGIMM_class, Instr.WORD_class

public abstract class Instr

extends java.lang.Object

implements InstrPrototype

The Instr class and its descendants represent instructions within the assembly code. The visitor pattern is applied here. Each instruction has an accept() method that allows it to be visited with double dispatch by a InstrVisitor. Each instruction in the AVR instruction set is represented by an inner class whose source has been generated from a simple specification in the Generator class.

See Also:

InstrVisitor, Generator

Nested Class Summary

static class	Instr.ADC I N S T R U C T I O N D E S C R I P T I O N S ---------------------------------------------------------------- These are the actual instruction descriptions that contain the constraints on operands and sizes, etc.
static class	Instr.ADD
static class	Instr.ADIW
static class	Instr.AND
static class	Instr.ANDI
static class	Instr.ASR
static class	Instr.BCLR
static class	Instr.BLD
static class	Instr.BRBC
static class	Instr.BRBS
static class	Instr.BRCC
static class	Instr.BRCS
static class	Instr.BREAK
static class	Instr.BREQ
static class	Instr.BRGE
static class	Instr.BRHC
static class	Instr.BRHS
static class	Instr.BRID
static class	Instr.BRIE
static class	Instr.BRLO
static class	Instr.BRLT
static class	Instr.BRMI
static class	Instr.BRNE
static class	Instr.BRPL
static class	Instr.BRSH
static class	Instr.BRTC
static class	Instr.BRTS
static class	Instr.BRVC
static class	Instr.BRVS
static class	Instr.BSET
static class	Instr.BST
static class	Instr.CALL
static class	Instr.CBI
static class	Instr.CBR
static class	Instr.CLC
static class	Instr.CLH
static class	Instr.CLI
static class	Instr.CLN
static class	Instr.CLR
static class	Instr.CLS
static class	Instr.CLT
static class	Instr.CLV
static class	Instr.CLZ
static class	Instr.COM
static class	Instr.CP
static class	Instr.CPC
static class	Instr.CPI
static class	Instr.CPSE
static class	Instr.DEC
static class	Instr.EICALL
static class	Instr.EIJMP
static class	Instr.ELPM
static class	Instr.ELPMD
static class	Instr.ELPMPI
static class	Instr.EOR
static class	Instr.FMUL
static class	Instr.FMULS
static class	Instr.FMULSU
static class	Instr.ICALL
static class	Instr.IJMP
static class	Instr.IMM_class
static class	Instr.ImmediateRequired The ImmediateRequired class represents an error in construction of an instance of Instr where the given operand is expected to be an immediate but is not.
static class	Instr.IMMIMM_class
static class	Instr.IMMREG_class
static class	Instr.IMMWORD_class
static class	Instr.IN
static class	Instr.INC
static class	Instr.InvalidImmediate The InvalidImmediate class represents an error in construction of an instance of Instr where the given immediate operand is not within the range that is specified by the instruction set manual.
static class	Instr.InvalidOperand The InvalidOperand class represents a runtime error thrown by the constructor of an instruction or the build method of a prototype when an operand does not meet the restrictions imposed by the AVR instruction set architecture.
static class	Instr.InvalidRegister The InvalidRegister class represents an error in constructing an instance of Instr where a register operand does not meet the instruction set specification.
static class	Instr.JMP
static class	Instr.LD
static class	Instr.LDD
static class	Instr.LDI
static class	Instr.LDPD
static class	Instr.LDPI
static class	Instr.LDS
static class	Instr.LPM
static class	Instr.LPMD
static class	Instr.LPMPI
static class	Instr.LSL
static class	Instr.LSR
static class	Instr.MOV
static class	Instr.MOVW
static class	Instr.MUL
static class	Instr.MULS
static class	Instr.MULSU
static class	Instr.NEG
static class	Instr.NONE_class
static class	Instr.NOP
static class	Instr.OR
static class	Instr.ORI
static class	Instr.OUT
static class	Instr.POP
static class	Instr.PUSH
static class	Instr.RCALL
static class	Instr.REG_class
static class	Instr.REGIMM_class
static class	Instr.REGIMMREG_class
static class	Instr.RegisterRequired The RegisterRequired class represents an error in construction of an instance of Instr where the given operand is expected to be a register but is not.
static class	Instr.REGREG_class A B S T R A C T C L A S S E S -------------------------------------------------------- These abstract implementations of the instruction simplify the specification of each individual instruction considerably.
static class	Instr.REGREGIMM_class
static class	Instr.RET
static class	Instr.RETI
static class	Instr.RJMP
static class	Instr.ROL
static class	Instr.ROR
static class	Instr.SBC
static class	Instr.SBCI
static class	Instr.SBI
static class	Instr.SBIC
static class	Instr.SBIS
static class	Instr.SBIW
static class	Instr.SBR
static class	Instr.SBRC
static class	Instr.SBRS
static class	Instr.SEC
static class	Instr.SEH
static class	Instr.SEI
static class	Instr.SEN
static class	Instr.SER
static class	Instr.SES
static class	Instr.SET
static class	Instr.SEV
static class	Instr.SEZ
static class	Instr.SLEEP
static class	Instr.SPM
static class	Instr.ST
static class	Instr.STD
static class	Instr.STPD
static class	Instr.STPI
static class	Instr.STS
static class	Instr.SUB
static class	Instr.SUBI
static class	Instr.SWAP
static class	Instr.TST
static class	Instr.WDR
static class	Instr.WORD_class
static class	Instr.WrongNumberOfOperands The WrongNumberOfOperands class represents a runtime error thrown by the build method of a prototype when the wrong number of operands is passed to build an instruction.

Constructor Summary

Instr()

Method Summary

abstract void	accept(InstrVisitor v) The accept() method is part of the visitor pattern for instructions.
int	getCycles() The getCycles() method returns the number of cylces consumed by the instruction in the default case.
abstract java.lang.String	getOperands() The getOperands() method returns a string representation of the operands of the instruction.
int	getSize() The getSize() method returns the size of the instruction in bytes.
java.lang.String	getVariant() The getVariant() method gets the variant of the instruction.
boolean	isInstr() The isInstr() method is part of the is/as convention for instructions and data as they are unified in the Elem interface.
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface avrora.core.InstrPrototype

build, getName

Constructor Detail

Instr

public Instr()

Method Detail

isInstr

public boolean isInstr()

The isInstr() method is part of the is/as convention for instructions and data as they are unified in the Elem interface. This convention avoids stupid casts and subtype tests by replacing them with virtual dispatch. In a small world, this is manageable.

Returns:

true because this object is an instruction

getOperands

public abstract java.lang.String getOperands()

The getOperands() method returns a string representation of the operands of the instruction. This is useful for printing and tracing of instructions as well as generating listings.

Returns:

a string representing the operands of the instruction

getVariant

public java.lang.String getVariant()

The getVariant() method gets the variant of the instruction. Since instructions like load and store can have multiple forms, each unique form is a named variant and its own class.

Specified by:

getVariant in interface InstrPrototype

Returns:

the name of this variant

getSize

public int getSize()

The getSize() method returns the size of the instruction in bytes.

Specified by:

getSize in interface InstrPrototype

Returns:

the size of this instruction in bytes

toString

public java.lang.String toString()

getCycles

public int getCycles()

The getCycles() method returns the number of cylces consumed by the instruction in the default case. Most instructions consume the same amount of clock cycles no matter what behavior. For example, 8-bit arithmetic takes one cycle, load and stores take two cycles, etc. Some instructions like the branch and skip instructions take more cycles if they are taken or not taken. In that case, this count returned is the smallest number of cycles that can be consumed by this instruction.

Returns:

the number of cycles that this instruction consumes

accept

public abstract void accept(InstrVisitor v)

The accept() method is part of the visitor pattern for instructions. The visitor pattern uses two virtual dispatches combined with memory overloading to achieve dispatching on multiple types. The result is clean and modular code.

Parameters:

v - the visitor to accept