README

The project includes 3 program: mips_asm, mips_emulator and mips_emulator_forwarding.

The mips_asm can translate the given mips assembly code to a simple format file. The file "code.asm" contains the instruction to be tested. Use the command bellow:

#./mips_asm code.asm

Then "code.bin" will be generate.

mips_emulator is a simple mips pipeline emulator that can support several instructions. 
mips_emulator_forwarding is an advanced version that use forwarding to reduce the stall cycles.

To test the emulator, use the command bellow:

#./mips_emulator < code.bin
#./mips_emulator_singel < code.bin

The output will be like this:
"xxxth clock cycle ended!"
PC=xx
xxx, xxx, xxx, xxx
r[0]=x ,r[1]=x ,r[2]=x ,r[3]=x ,r[4]=x ,r[5]=x ,r[6]=x ,r[7]=x ,r[8]=x ,r[9]=x

(The 3rd line show the instructions in the registers between each stage, IF_ID, ID_EX, EX_MEM, MEM_WB)

In my test data, the result of "BLTZ" branch instruction will only be false for 2 times. So the total instructions to be executed will be 4+7x20+2+1=147.

For mips_emulator, 352 clocl cycles are needed. The CPI is 2.39.

For mips_emulator_forwarding, 210 clocl cycles are needed. The CPI is 1.43.