~:  8051 Instruction Set  :~
Here one can find complete instruction set of 8051 micro-controller. Complete information regarding each instruction like operational explanation, addressing mode, no. of byte occupied, no. of cycles used etc is given. So just, go through it. It’s a ready reference.
 
 
All 8051 instructions are broadly classify in to four groups data moving, logical, arithmetic and branching.
 
 
Data moving / handling Instructions: -
 
Mnemonics
 
Operational description
 
Addressing mode
 
No. of bytes occupied
 
No. of cycles used
 
Mov a,#num
 
Copy the immediate data num in to acc
 
immediate
 
2
 
1
 
Mov Rx,a
 
Copy the data from acc to Rx
 
register
 
1
 
1
 
Mov a,Rx
 
Copy the data from Rx to acc
 
register
 
1
 
1
 
Mov Rx,#num
 
Copy the immediate data num in to Rx
 
immediate
 
2
 
1
 
Mov a,add
 
Copy the data from direct address add to acc
 
direct
 
2
 
1
 
Mov add,a
 
Copy the data from acc to direct address add
 
direct
 
2
 
1
 
Mov add,#num
 
Copy the immediate data num in to direct address
 
direct
 
3
 
2
 
Mov add1,add2
 
Copy the data from add2 to add1
 
direct
 
3
 
2
 
Mov Rx,add
 
Copy the data from direct address add to Rx
 
direct
 
2
 
2
 
Mov add,Rx
 
Copy the data from Rx to direct address add
 
direct
 
2
 
2
 
Mov @Rp,a
 
Copy the data in acc to address in Rp
 
Indirect
 
1
 
1
 
Mov a,@Rp
 
Copy the data that is at address in Rp to acc
 
Indirect
 
1
 
1
 
Mov add,@Rp
 
Copy the data that is at address in Rp to add
 
Indirect
 
2
 
2
 
Mov @Rp,add
 
Copy the data in add to address in Rp
 
Indirect
 
2
 
2
 
Mov @Rp,#num
 
Copy the immediate byte num to the address in Rp
 
Indirect
 
2
 
1
 
Movx a,@Rp
 
Copy the content of external add in Rp to acc
 
Indirect
 
1
 
2
 
Movx a,@DPTR
 
Copy the content of external add in DPTR to acc
 
Indirect
 
1
 
2
 
Movx @Rp,a