Chapter 8 Writing Source Statements
Expressions 141

8.7.3 Expression Syntax

Below is an expression syntax diagram
Expression Syntax
NOTE: When the expressions starting with parenthesis are coded to the operands of
Machine language instructions, it will be regarded as an address-reference. To
be proceeded as expressions, put 0+ before the parenthesis and distinguish
them from others.
mov (10+5), d0 ; move the value of address 15 to d0
; equal to mov(15), d0
mov (0+(10+5), d0 ; move the value of constant 15 to d0 equal to mov 15, d0
mov (10+5)+2, d0 ; Error. "(10+5)" is regarded as an address-reference.
; It causes syntax error.
(expression )
expression expression
binary operator
symbol
constant
*
unary operator