|Red Hat Enterprise Linux 3: Using as, the Gnu Assembler|
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! is the line comment character.
; can be used instead of a newline to separate statements.
Since $ has no special meaning, you may use it in symbol names.
You can use the predefined symbols r0, r1, r2, r3, r4, r5, r6, and r7 to refer to the H8/500 registers.
The H8/500 also has these control registers:
stack top pointer
condition code register
All registers are 16 bits long. To represent 32 bit numbers, use two adjacent registers; for distant memory addresses, use one of the segment pointers (cp for the program counter; dp for r0-r3; ep for r4 and r5; and tp for r6 and r7.
as understands the following addressing modes for the H8/500:
Register indirect with 8 bit signed displacement
Register indirect with 16 bit signed displacement
Register indirect with pre-decrement
Register indirect with post-increment
8 bit absolute address
16 bit absolute address
8 bit immediate
16 bit immediate