as
has no additional command-line options for the Hitachi
H8/500 family.
`!' 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:
cp
dp
bp
tp
ep
sr
ccr
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:
Rn
@Rn
@(d:8, Rn)
@(d:16, Rn)
@-Rn
@Rn+
@aa:8
@aa:16
#xx:8
#xx:16
The H8/500 family has no hardware floating point, but the .float
directive generates IEEE floating-point numbers for compatibility
with other development tools.
as
has no machine-dependent directives for the H8/500.
However, on this platform the `.int' and `.word' directives
generate 16-bit numbers.
For detailed information on the H8/500 machine instruction set, see H8/500 Series Programming Manual (Hitachi M21T001).
as
implements all the standard H8/500 opcodes. No additional
pseudo-instructions are needed on this family.
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