4.9.4 Legal Expressions

With the exception of the following expression contexts, there is no restriction on combinations of operations, constants, internally defined symbols, and externally defined symbols.

• When using the register relative addressing mode, the expression in brackets or parenthesis must be a well-defined expression, as described in Section 4.9.3. For example:
*+A4[15]
• Expressions used to describe the offset in register relative addressing mode for the registers B14 and B15, or expressions used as the operand to the branch instruction, are subject to the same limitations. For these two cases, all legal expressions can be reduced to one of two forms:
*+XA4[7]

	relocatable symbol ± absolute symbol	B (extern_1-10)
	or
	a well-defined expression	*+B14/B15[14]