3. Write a MIPS test program for the AND, OR, and SUB instructions and run it on the VHDL MIPS simulation. These are all R-format instructions just like the ADD instruction. Modifications to the memory initialization files, program.mif and dmemory.mif, (i.e. only if you use data from memory in the test program) will be required. Registers have been preloaded with the register number to make it easy to run short test programs.