Assembler Project Revision

Loads (LW, LH, LB):

Instruction	First Operand	Second Operand	Third Operand	Example	Action taken
Load Byte	Dest Reg	Src Reg	Variable Name	LB R1, R2, X	R1 <- MEM[(contents of R2)+Address Offset]
Load Halfword	Dest Reg	Src Reg	Variable Name	LH R1, R2, X	R1 <- MEM[(contents of R2)+Address Offset]
Load Word	Dest Reg	Src Reg	Variable Name	LW R1, R2, X	R1 <- MEM[(contents of R2)+Address Offset]

Note: Address Offset refers to the result of calculating the distance between the current location and the specified data variable.

Example:

   LW  R6, R7, X  ; assume that the offset for X is 2A

The opcode for this instruction is 05, the source register is R7 and the destination register is R6.

opcode	source register	destination register	immediate value
000101	00111	00110	0000000000101010

Regrouped, this produces:

0001 0100 1110 0110 0000 0000 0010 1010

or,   14E6002A   in hexadecimal

Stores (SW, SH, SB):

Instruction	First Operand	Second Operand	Third Operand	Example	Action taken
Store Byte	Dest Reg	Variable Name	Src Reg	SB R1, X, R2	MEM[(contents of R1)+Address Offset] <- R2
Store Halfword	Dest Reg	Variable Name	Src Reg	SH R1, X, R2	MEM[(contents of R1)+Address Offset] <- R2
Store Word	Dest Reg	Variable Name	Src Reg	SW R1, X, R2	MEM[(contents of R1)+Address Offset] <- R2

Note: Address Offset refers to the result of calculating the distance between the current location and the specified data variable.

Example:

   SH  R4, X, R5  ; assume that the offset for X is 32

The opcode for this instruction is 07, the source register is R5 and the destination register is R4.

opcode	source register	destination register	immediate value
000111	00101	00100	0000000000110010

Regrouped, this produces:

0001 1100 1010 0100 0000 0000 0011 0010

or,   1CA40032   in hexadecimal

Jump Absolute (JA, JAL):

Instruction	First Operand	Example	Action taken
Jump Absolute	Dest Reg (Address Register)	JA R1	PC <- (contents of R1)
Jump Absolute and Link	Dest Reg (Address Register)	JAL R1	R31 <- PC, PC <- (contents of R1)

Example:

   JA  R9

The opcode for this instruction is 0C and the destination register is R9. There is no source register and no immediate value.

opcode	source register	destination register	immediate value
001100	00000	01001	0000000000000000

Regrouped, this produces:

0011 0000 0000 1001 0000 0000 0000 0000

or,   30090000   in hexadecimal