Register Transfer Language

The symbolic notation used to describe the micro operation transfers among register is called a register transfer language.
A register transfer language is a system for expressing in symbolic form the micro operation sequences among the register of a digital module.

For example,

R1 ← R2

  • This statement denotes a transfer of the content of register R2 into register R1.
  • Here, content of R1 is replaced by content of R2.
  • Content of R2 is not affected by this transfer.

If there is a condition, such that.

If (P = 1) then (R1  ← R2)
Where P is a control signal generated by the control bus. 

Above statement can be used as,
P=1: R1 ← R2

The control condition ‘P=1’ is terminated with a colon. It symbolizes the requirement that the transfer operation be executed by the hardware only if P= 1.

Basic symbols for Register Transfer Language

Letters & numeralsDenotes a registerMAR, R2
Parenthesis ( )Denotes a part of a registerR2(0-7), R2(L)
Arrow ←Denotes transfer of informationR2 ← R1
Comma ,Separates two micro operationsR2 ← R1, R1 ← R2  

For example,

T=1: R2 ← R1, R1 ← R2 

  • Registers (R1, R2) are denoted by capital letters, and numerals. 
  • Parentheses ( ) are used to denote a part of a register.
  • The arrow (←) denotes a transfer of information and the direction of transfer.
  • A comma ( , ) is used to separate two or more operations that are executed at the same time.


  1. William stalling ,“Computer Architecture and Organization” PHI
  2. Morris Mano , “Computer System Organization ”PHI