Skip to content. Skip to navigation. For class, you should use the register names, not the corresponding register numbers. Remainder stored in special register hi Quotient stored in special register lo. All conditional branch instructions compare the values in two registers together.
If the comparison test is true, the branch is taken i. Otherwise, the processor continues on to the next instruction. Note 1: It is much easier to use a label for the branch instructions instead of an absolute number. The label "equal" should be defined somewhere else in the code.
Note 2: There are many variations of the above instructions that will simplify writing programs! Note: It is much easier to use a label for the jump instructions instead of an absolute number. That label should be defined somewhere else in the code.
The SPIM simulator provides a number of useful system calls. These are simulatedand do not represent MIPS processor instructi ons. System calls are used for input and output, and to exit the program. They are initiated by the syscall instruction. In other words, not all registers are used by all system calls.
An assembler directive allows you to request the assembler to do something when converting your source code to binary code. MIPS has 32 general-purpose registers that could, technically, be used in any manner the programmer desires. However, by convention, registers have been divided into groups and used for different purposes.
Registers have both a number used by the hardware and a name used by the assembly programmer. Skip to navigation Personal tools Log in. Search Site only in current section. Advanced Search…. Lower 16 bits are set to zero. Copy from register to register. Upper 32 bits stored in special register hi Lower 32 bits stored in special register lo. Pseudo-instruction provided by assembler, not processor! Loads computed address of label not its contents into register. Loads immediate value into register.
Returns the address to a block of memory containing n additional bytes. Useful for dynamic memory allocation.
MIPS Assembly/Instruction Formats
Strings are in double-quotes, i. For example.This is a description of the MIPS instruction set, their meanings, syntax, semantics, and bit encodings. The syntax given for each instruction refers to the assembly language syntax supported by the MIPS assembler. Hyphens in the encoding indicate "don't care" bits which are not considered when an instruction is being decoded.
The manner in which the processor executes an instruction and advances its program counters is as follows:. This behavior is indicated in the instruction specifications below.
This function is defined as follows:. Note: ALL arithmetic immediate values are sign-extended. After that, they are handled as signed or unsigned 32 bit numbers, depending upon the instruction.
The only difference between signed and unsigned instructions is that signed instructions can generate an overflow exception and unsigned instructions can not. The instruction descriptions are given below:. Adds two registers and stores the result in a register. Adds a register and a sign-extended immediate value and stores the result in a register.
Bitwise ands two registers and stores the result in a register. Bitwise ands a register and an immediate value and stores the result in a register. Branches if the two registers are equal. Branches if the register is greater than or equal to zero. Branches if the register is greater than zero. Branches if the register is less than or equal to zero.
Branches if the register is less than zero. Branches if the two registers are not equal. Jumps to the calculated address. A byte is loaded into a register from the specified address.
The immediate value is shifted left 16 bits and stored in the register. The lower 16 bits are zeroes. A word is loaded into a register from the specified address. The contents of register HI are moved to the specified register. The contents of register LO are moved to the specified register. Performs no operation. Bitwise logical ors two registers and stores the result in a register. Bitwise ors a register and an immediate value and stores the result in a register.
Shifts a register value left by the shift amount listed in the instruction and places the result in a third register. Zeroes are shifted in.
Shifts a register value left by the value in a second register and places the result in a third register. It gets zero otherwise. Shifts a register value right by the shift amount shamt and places the value in the destination register. The sign bit is shifted in. Subtracts two registers and stores the result in a register. Generates a software interrupt.The MIPS32 architecture is a highly performance-efficient industry standard architecture that is at the heart of billions of electronic products, from tiny microcontrollers to high-end networking equipment.
It provides a robust instruction set, scalability from bits to bits, a broad-spectrum of software development tools and widespread support from numerous partners and licensees.
These technologies, in conjunction with technologies such as multi-threading MTDSP extensions and EVA Enhanced Virtual Addressing enrich the architecture for use with modern software workloads which require larger memory sizes, increased computational horsepower and secure execution environments. The architecture is streamlined to support optimized execution of high-level languages. Arithmetic and logic operations use a three-operand format, allowing compilers to optimize complex expressions formulation.
Availability of 32 general-purpose registers enables compilers to further optimize code generation for performance by keeping frequently accessed data in registers. A set of registers reflects the configuration of the caches, MMU, TLB, and other privileged features implemented in each core. By standardizing privileged mode and memory management and providing the information through the configuration registers, the MIPS32 architecture enables real-time operating systems, other development tools, and application code to be implemented once and reused with various members of both the MIPS32 and the MIPS64 processor families.Datapath Control R - Type
Flexibility of its high-performance caches and memory management schemes are strengths of the MIPS architecture. The MIPS32 architecture extends these advantages with well-defined cache control options. The size of the instruction and data caches can range from bytes to 4 MB. The data cache can employ either a write-back or write-through policy. A no-cache option can also be specified.The early MIPS architectures were bit only; bit versions were developed later.
The MIPS architecture has several optional extensions. Computer architecture courses in universities and technical schools often study the MIPS architecture.
MIPS-I Assembly Language Instruction Set
A  : It was designed for use in personal, workstation, and server computers. ARC found little success in personal computers, but the R and the R derivative were widely used in workstation and server computers, especially by its largest user, Silicon Graphics. Other uses of the R included high-end embedded systems and supercomputers.
Quantum Effect Design 's R and its derivatives was widely used in high-end embedded systems and low-end workstations and servers. The design of the R began at Silicon Graphics, Inc. The R and R found use in high-end embedded systems, personal computers, and low-end workstations and servers. The former was to have been the first MIPS V implementation, and was due to be introduced in the first half of Up to MIPS V, each successive version was a strict superset of the previous version, but this property was found to be a problem, [ citation needed ] and the architecture definition was changed to define a bit and a bit architecture: MIPS32 and MIPS Both were introduced in In Marchone version of the architecture was made available under a royalty-free license,  but later that year the program was shut down again.
For integer multiplication and division instructions, which run asynchronously from other instructions, a pair of bit registers, HI and LOare provided. The program counter has 32 bits. The two low-order bits always contain zero since MIPS I instructions are 32 bits long and are aligned to their natural word boundaries. Instructions are divided into three types: R, I and J.
Every instruction starts with a 6-bit opcode. In addition to the opcode, R-type instructions specify three registers, a shift amount field, and a function field; I-type instructions specify two registers and a bit immediate value; J-type instructions follow the opcode with a bit jump target.
MIPS I has instructions that load and store 8-bit bytes, bit halfwords, and bit words. Since MIPS I is a bit architecture, loading quantities fewer than 32 bits requires the datum to be either signed- or zero-extended to 32 bits.
The load instructions suffixed by "unsigned" perform zero extension; otherwise sign extension is performed. All load and store instructions compute the memory address by summing the base with the sign-extended bit immediate. MIPS I requires all memory accesses to be aligned to their natural word boundaries, otherwise an exception is signaled. All load instructions are followed by a load delay slot. The instruction in the load delay slot cannot use the data loaded by the load instruction.
The load delay slot can be filled with an instruction that is not dependent on the load; a nop is substituted if such an instruction cannot be found.
MIPS I has instructions to perform addition and subtraction. Alternatively, addition can source one of the operands from a bit immediate which is sign-extended to 32 bits. The instructions for addition and subtraction have two variants: by default, an exception is signaled if the result overflows; instructions with the "unsigned" suffix do not signal an exception.R instructions are used when all the data values used by the instruction are located in registers.
Where "OP" is the mnemonic for the particular instruction. As an example, the add mnemonic can be used as:. In the main narrative of this book, the operands will be denoted by these names. Converting an R mnemonic into the equivalent binary machine code is performed in the following way:.
Because several functions can have the same opcode, R-Type instructions need a function Func code to identify what exactly is being done - for example, 0x00 refers to an ALU operation and 0x20 refers to ADDing specifically. I instructions are used when the instruction must operate on an immediate value and a register value. Immediate values may be a maximum of 16 bits long.
Larger numbers may not be manipulated by immediate instructions. Where rt is the target register, rs is the source register, and IMM is the immediate value. The immediate value can be up to 16 bits long. For instance, the addi instruction can be called as:.
J instructions are used when a jump needs to be performed. The J instruction has the most space for an immediate value, because addresses are large numbers. FR instructions are similar to the R instructions described above, except they are reserved for use with floating-point numbers:.
FI instructions are similar to the I instructions described above, except they are reserved for use with floating-point numbers:. The following table contains a listing of MIPS instructions and the corresponding opcodes. Opcode and funct numbers are all listed in hexadecimal.
From Wikibooks, open books for an open world. MIPS Assembly. Namespaces Book Discussion.Instruction set : each instruction in the instruction set describes one particular CUP operation.
Each instruction is represented in both assembly language by the mnimonics and machine language binary by a word of 32 bits subdivided into several fields. There are different types of instructions: Computational Instructions These instructions are for arithmetic or logic manipulations. In general they operate on two operands and store the result. Opcode can be: add, sub, mult, div, and, or, etc.
Note: The destination register is specified in the first field following the opcode field in the assembly language instruction, but the last 5-bit field in the binary machine language instruction.
In all R-type data manipulation instructions arithmetic, logical, shiftthe operations are specified by the function field 6 least significant bits in the binary instruction, with the opcode field 6 most significant bits all equal to zero. Shift Instructions.
Load word from MM to register:. But some time it is needed to conditionally or unconditionally jump to some other part of the program e. Branch to a labeled statement if two variables are equal:. Set a register to 1 if first variable is smaller than the second, set the register to 0 otherwise. Jump unconditionally to a certain statement whose address is given in a register:. Return to calling routine: To return from subroutine to the calling routine, the last statement of the subroutine must be:.Mips registers based this tutorial will be helpful in understanding the concepts of mips registers in computer architecture.
Register is a sequential circuit and used to store the data. Registers consist of various flip flops. Register are also used to transfer data and instructions that are used by the Central Processing Unit. These registers are also known as special purpose processor registers. In mips registers the term mips stands for Million Instructions Per Second.
Control unit implementation technique that allows instructions to be processed in series, dividing them into phases. With a single instruction execution channel it is possible to keep executing several instructions simultaneously, each one in a different phase.
The MIPS instruction set is quite similar to what one finds in many modern processors. The Arithmetic Logic Unit ALU executes the addition subtractionsubtraction subtractionand logical logical instructions. A bit data item stored in a register or memory location with an address divisible by 4 is known as a word.
For now, suppose a word retains a statement or a signed integer, though later you will see that it can also retain an unsigned integer, floating point number, or ASCII character string. Since words in mips registers are stored in byte addressable memory, a convention is required to establish which end of the word appears in the first byte the one with the lowest memory address.
Of the two possible conventions in this regard, MIPS uses the big-endian highest ending schema, where the most significant end appears first. The hardware principle that relates size to speed suggests that memory should be slower than records because the size of the recordset is less than that of memory. Access to data is faster if the data is in records. And data is most useful when it is in registers because an arithmetic statement is applied to two registers, while memory accesses only manipulate one data.
In conclusion, the data in the records in mips registers takes less time and has a higher productivity than the data in memory. To increase performance, MIPS compilers must use the logs efficiently. Please provide your feedback or leave comment so that we can improve and provide you a good quality tutorials.
MIPS Instruction Set
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