Virtual Machine

MIPS Reference

Registers

The MIPS architecture is difficult to program directly because these computers were designed to be programmed in high-level languages and present an interface appropriate for compilers rather than assembly language programmers. The programming complexity is a result of the use of delayed instructions -- requiring 2 cycles to execute which allows some other operation to be performed before the delayed instruction is executed.

Base Machine. The base machine of any MIPS architecture is the set of instructions that the hardware understands and can execute directly.

Virtual Machine. To help with assembly language programming, the MIPS assembler implements a virtual machine -- makes it appear that you are programming a different machine than the base machine.

• The virtual computer eliminates the delayed instructions.
• It provides a richer instruction set than the base machine by providing pseudoinstructions.
  • appear as real instructions in an assembly language program
  • but they must be converted to base machine instructions by the assembler

MIPS Reference

Registers