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Chapter 27. M68HC11 and M68HC12 Dependent Features

 short branchs

The

 short branchs

option turns off the translation of relative branches into absolute branches

when the branch offset is out of range. By default

as

transforms the relative branch (

bsr

,

bgt

,

bge

,

beq

,

bne

,

ble

,

blt

,

bhi

,

bcc

,

bls

,

bcs

,

bmi

,

bvs

,

bvs

,

bra

) into an absolute branch

when the offset is out of the  128 .. 127 range. In that case, the

bsr

instruction is translated into

a

jsr

, the

bra

instruction is translated into a

jmp

and the conditional branchs instructions are

inverted and followed by a

jmp

. This option disables these translations and

as

will generate an

error if a relative branch is out of range. This option does not affect the optimization associated

to the

jbra

,

jbsr

and

jbXX

pseudo opcodes.

 force long branchs

The

 force long branchs

option forces the translation of relative branches into absolute

branches. This option does not affect the optimization associated to the

jbra

,

jbsr

and

jbXX

pseudo opcodes.

 print insn syntax

You can use the

 print insn syntax

option to obtain the syntax description of the instruction

when an error is detected.

 print opcodes

The

 print opcodes

option prints the list of all the instructions with their syntax. The first

item of each line represents the instruction name and the rest of the line indicates the possible

operands for that instruction. The list is printed in alphabetical order. Once the list is printed

as

exits.

 generate example

The

 generate example

option is similar to

 print opcodes

but it generates an example

for each instruction instead.

27.2. Syntax

In the M68HC11 syntax, the instruction name comes first and it may be followed by one or several

operands (up to three). Operands are separated by comma (

,

). In the normal mode,

as

will complain if

too many operands are specified for a given instruction. In the MRI mode (turned on with

 M

option),

it will treat them as comments. Example:

inx

lda

#23

bset 2,x #4

brclr *bot #8 foo

The following addressing modes are understood for 68HC11 and 68HC12:

Immediate

#number