:- Instrcution Set -:
Load/Store Instructions
See
Load Instructions Notes for more informations.
Load/Store Instructions
See
Load Instructions Notes for more informations.
| Instruction |
|
|---|---|
| lb rd,offset(base) | Load Byte.
Loads the 8bit addressed by offset+base into the low order 8bit of rd. The byte is sign-extended in rd. Example 1: byte=0x0 .... 0x7f (dec: 0...127) is loaded into t5. before: t5=undefined. load: lb t5,10(t0) / let the byte be 0x2F after: t5=0x0000002F. Example 2: byte=0x80 .... 0xff (dec: 0...-128) is loaded into t5. before: t5=undefined. load: lb t5,10(t0) / let the byte be 0xEA after: t5=0xFFFFFFEA |
| lbu rd,offset(base) | Load Byte
Unsigned.
Loads the 8bit addressed by offset+base into the low order 8bit of rd. The leading 24 bit are cleared. |
| lh rd,offset(base) | Load Halfword.
Loads the 16bit addressed by offset+base into the low order 16bit of rd. The halfword is placed as sign-extended word in rd. Example 1: halfword=0x0...0x7fff (dec 0...32737) is loaded into t4. before: t4=undefined load: lh t4,16(t0) / let the halfword be 0x0815 after: t4=0x00000815 Example 2: halfword=0x8000...0xffff(dec 0...-32738) is loaded into t6. before:t6=undefined load: lh t6,1024(t0) /let the halfword be 0xFACE after: t6=0xFFFFFACE |
| lhu rd,offset(base) | Load Halfword
Unsigned.
Load the 16bit addressed by offset+base into the low order 16bit of rd. The high order 16bit are cleared. |
| lw rd,offset(base) | Load Word.
The word addressed by offset+base is placed into rd. |
| lwl rd,offset(base) | Load Word Left. |
| lwr rd,offset(base) | Load Word Right. |
| sb rd,offset(base) | Store Byte.
The lowest 8bit of rd are stored in memory addressed by offset+base. |
| sh rd,offset(base) | Store Halfword.
The lower 16bit of rd are stored in memory addressed by offset+base. |
| sw rd,offset(base) | Store Word.
The contents of rd is stored in memory addressed by offset+base. |
| swl rd,offset(base) | Store Word Left. |
| swr rd,offset(base) | Store Word Right. |
Arithmetic Instructions (Immediate-Type)
| Instruction |
|
|---|---|
| addi rd,rs,immediate | Add Immediate.
Adds the contents of rs with signed immedate value and stores the result in rd. |
| addiu rd,rs,immediate | Add Immediate
Unsigned.
Adds the contents of rs with unsigned immedate value and stores the result in rd. |
| andi rd,rs,immediate | AND Immediate.
ANDs bitwise the contents of rs with immediate value. The result is placed in rd. |
| ori rd,rs,immediate | OR Immediate.
ORs bitwise the contents of rs with immediate value. The result is placed in rd. |
| xori rd,rs,immediate | XOR Immediate.
XORs bitwise the contents of rs with immedate value. The result is placed in rd. |
| slti rd,rs,immediate | Set on Less
Than Immediate.
Sets rd=1 if rs<immediate, else rd=0. The values are seen as signed integers. |
| sltiu rd,rs,immediate | Set on Less
Than Immediate Unsigned.
Sets rd=1 if rs<immedate, else rd=0. The values are seen as unsigned integers. |
| lui rd,immediate | Load Upper
Immediate.
Loads the immediate value into the high order 16 bit of rd. |
Arithmetic Instructions (Register Type)
| Instruction |
|
|---|---|
| add rd,rs,rt | Add.
Adds the contents of rs and rt and stores the result in rd. |
| addu rd,rs,rt | Add Unsigned.
Adds the contents of rs(unsigned) and rt(unsigned) and stores the result in rd. |
| sub rd,rs,rt | Subtrsct.
Subtrscts the contents of rt from rs and stores the result inrd. |
| subu rd,rs,rt | Subtrsct
Unsigned.
Subtrscts the contents of rt(unsigned) from rs(unsigned) and stores the result in rd. |
| and rd,rs,rt | AND.
ANDs bitwise the contents of rs and rt. The result is placed in rd. |
| or rd,rs,rt | OR.
ORs bitwise the contents of rs and rt. The result is placed in rd. |
| xor rd,rs,rt | XOR.
XORs bitwise the contents of rs and rt. The result is placed in rd. |
| nor rd,rs,rt | NOR.
NOTs bitwise the contents of rs and rt. The result is placed in rd. |
| slt rd,rs,rt | Set on Less
Than.
Sets rd=1 if rs<rt, else rd=0. The values are seen as signed integers. (example: 0x00008000<0x00007FFF) |
| sltu rd,rs,rt | Set on Less
Than Unsigned.
Sets rd=1 if rs<rt, else rd=0. The values are seen as unsigned integers. (example: 0x00008000>0x00007FFF) |
Shift Instructions
| Instruction |
|
|---|---|
| sll rd,rs,shamt | Shift Left
Logical.
The contents of rs is shifted left by the amount of bits specified by shamt and the result is placed in rd. shamt is 5 bit wide, so 1 up to 32 bit shift can be performed. |
| srl rd,rs,shamt | Shift Right
Logical.
The contents of rs is shifted right by the amount of bits specified by shamt and the result is placed in rd. |
| sra rd,rs,shamt | Shift Right
Arithmetic.
The contents of rs is shifted right by the amount of bits specified by shamt and the result is placed in rd. The sign bit is beeing kept. Example: before: t7=0x80000000 shift: srs t7,t7,1 after: t7=0xC0000000 |
| sllv rd,rs,rt | Shift Left
Logical Variable.
The contents of rs is shifted left by the amount of bits specified in rt and the result is palced in rd. |
| srlv rd,rs,rt | Shift Right
Logical Variable.
The contents of rs is shifted right by the amount of bits specified in rt and the result is placed in rd. |
| srav rd,rs,rt | Shift Right
Arithmetic Variable.
The contents of rs is shifted right by the amount of bits specified in rt and the result is placed in rd. The sign bit is beeing kept. |
Multiply/Divide Intructions
See Multiply/Divide
Notes for more informations.
| Instruction |
|
|---|---|
| mult rd,rs | Multiply.
Multiplies the contents of rd by rs and stores the 64bit value in hi/lo. |
| multu rd,rs | Multiply
Unsigned.
Multiplies the unsgined contents of rd by the unsigned contents of rs and stores the 64bit result in hi/lo. |
| div rd,rs | Divide.
Divides the contents of rd by rs and stores the 32bit quotient in lo and the 32bit remainder in hi. |
| divu rd,rs | Divide Unsigned.
Divides the unsigned contes of rd by the unsigned contents of rs and stores the 32bit quotient in lo and the 32bit remainder in hi. |
| mfhi rd | Move from
HI.
Stores the contents of hi in rd. |
| mflo rd | Move from
LO.
Stores the contents of lo in rd. |
| mthi rd | Move to
HI.
Moves the contents of rd in hi. |
| mtlo rd | Move to
LO.
Moves the contents of rd in lo. |
Jump/Branch Instructions
See Jump/Branch
Notes for more informations.
| Instruction |
|
|---|---|
| j target | Jump.
Uncoditional jump to target.The target address is calculated (pc+4)+target. target is seen as 26bit signed integer. In assembly we will use labels. |
| jal target | Jump And
Link.
Unconditional jump to target. The address pc+8 is stored in rs register ($31/R_RA). |
| jr rd | Jump Register.
The contents of rd is loaded in pc. |
| jalr rd | Jump And
Link Register.
The address pc+8 is stored in rs register ($31/R_RA). The contents of rd is loaded in pc. |
| beq rd,rs,offset | Branch if
Equal.
Branch to offset if rd==rs. offset specifies a relative value where to continue program if condition is true. (label) |
| bne rd,rs,offset | Branch on
Not Equal.
Branch to offset if rd!=rs. (see beq) |
| blez rd,offset | Branch on
Lower than or Equal Zero.
Branch to offset if rd<=0. (see beq) |
| bgtz rd,offset | Branch on
Greater Than Zero.
Branch to offset if rd>0. (see beq) |
| bltz rd,offset | Branch if
Lower Than Zero.
Branch to offset if rd<0.(see beq) |
| bgez rd,offset | Branch if
Greater than or Equal Zero.
Branch to offset if rd>=0. (see beq) |
| bltzal rd,offset | Branch if
Lower Than Zero And Link.
If rd<0 then store the pc+8 in ra (R_RA/$31) and branch to offset. (see beq) |
| bgezal rd,offset | Branch if
Greater than or Equal Zero And Link.
If rd>=0 then store the pc+8 in ra (R_RA/$31) and branch to offset. (see beq) |
Special Instructions
(not used
in example functions)
| Instruction |
|
|---|---|
| syscall | System Call.
Initialize System-Call. |
| break | Breakpoint.
Executes the Exception Handler. |
System Control Coprocessor
Instructions
(not used
in example functions)
| Instruction |
|
|---|---|
| mfc0 rs,RD | Move from
Sytem Control Coprocessor.
Moves the contents from the system control register RD in the general register rs. |
| mtc0 rs,RS | Move to
System Control Coprocessor.
Moves the contents from the general register rs in the system control register RD. |
| rfe | Restore From Exception. |
| tlbr | Read Indexed TLB Entry. |
| tlbwi | Write Indexed TLB Entry. |
| tlbwr | Write Random TLB Entry. |
| tlbp | Probe TLB for matching Entry. |
Coprocessor Instructions
(not used
in example functions) >
| Instruction |
|
|---|---|
| lwcz | Load Word from Coprocessor. |
| swcz | Store Word to Coprocessor. |
| mtcz | Move to Coprocessor. |
| mfcz | Move from Coprocessor. |
| ctcz | Move Control To Coprocessor. |
| cfcz | Move Control From Coprocessor. |
| copz | Coprocessor Operantion. |
| bczt | Branch on Coprocessor z True. |
| bczf | Branch on Coprocessor z False. |