LANGUAGES OF THE COMPUTER 2 PART 1 (DECODING MACHINE LANGUAGE)

Decoding Machine Language

-----> six machine language instructions in hexadecimal:

     00001025_hex   

  0005402A_hex

                                                         
  11000003_hex

                                                
  00441020_hex

  20A5FFFF_hex 

  08100001_hex

1.Firstly we must  convert hex to binary

00001025_{hex   =} 00000000000000000001000000100101
0005402A_{hex  =}   00000000000001010100000000101010
11000003_{hex    =}  00010001000000000000000000000011 
00441020_{hex  =}   00000000010001000001000000100000
20A5FFFF_hex  = 00100000101001011111111111111111
08100001_{hex  =}   00001000000100000000000000000001

2.Ok,after tahat we identify the  opcode and format


*** Here some tips to identify which format should we use ( ^ _ ^ )


 Look at opcode:

  ***which is first 6 bits  of the binary number

[ 000000] 00000000000001000000100101

[ 000000] 00000001010100000000101010

[ 000100] 01000000000000000000000011

[ 000000] 00010001000001000000100000

[ 001000] 00101001011111111111111111 

[ 000010] 00000100000000000000000001

 0   ------> R-Format

2 or 3 ------> J-Format

 otherwise------>  I-Format

0	rs	rt	rd	shamt	funct
1,4-31	rs	rt	immediate
2 or 3	Target address

op = 6 bits
rs  = 5bits
rd = 5bits
shamt = 5 bits
funct = 6 bits
immediate = 16 bits
address = 26 bits

Ok , got it?Lets continue the next step!!!!

3.Translate  to MIPS assembly instructions.

        or $v0 , $0 , $0

loop :  $v0 , $0 ,$a1

         beq $t0  , $0 , Exit

         add $v0  ,$v0  , $a0

         addi $a1 , $a1 , -1

          j Loop

Exit

Ok done!!

post by; Nursyahirah Syafiqah binti Baharim