164

Chapter 27. M68HC11 and M68HC12 Dependent Features

Displacement Width

+                                                             +

|

Options

|

|

  short branchs

  force long branchs

|

+                          +                                  +

Op |BYTE

WORD

| BYTE

WORD

|

+                          +                                  +

bsr | bsr

pc rel

error

|

jsr

abs

|

bra | bra

pc rel

error

|

jmp

abs

|

jbsr | bsr

pc rel

jsr

abs

| bsr

pc rel

jsr

abs

|

jbra | bra

pc rel

jmp

abs

| bra

pc rel

jmp

abs

|

bXX | bXX

pc rel

error

|

bNX +3; jmp

abs

|

jbXX | bXX

pc rel

bNX +3;

| bXX

pc rel

bNX +3; jmp

abs

|

|

jmp

abs

|

|

+                          +                                  +

XX: condition

NX: negative of condition XX

jbsr

jbra

These are the simplest jump pseudo operations; they always map to one particular machine in 

struction, depending on the displacement to the branch target.

jbXX

Here,

jbXX

stands for an entire family of pseudo operations, where

XX

is a conditional branch or

condition code test. The full list of pseudo ops in this family is:

jbcc

jbeq

jbge

jbgt

jbhi

jbvs

jbpl

jblo

jbcs

jbne

jblt

jble

jbls

jbvc

jbmi

For the cases of non PC relative displacements and long displacements,

as

issues a longer code

fragment in terms of

NX

, the opposite condition to

XX

. For example, for the non PC relative case:

jbXX foo

gives

bNXs oof

jmp foo

oof: