naveendavisv wrote
can we directly assign the register  with values ?
like  R0 =2
       R1 =3
 
R0, 
R1, etc. are built-in symbols for memory addresses.  To write values to memory you need to have the value in the D register and the memory address in the A register, and then execute M=D.
Note that you can write -1, 0 and 1 directly to memory as in M=0.
--Mark