Program Control Instructions - Motorola MC68030 User Manual

3.2.8 Program Control Instructions

A set of subroutine call and return instructions and conditional and unconditional branch
instructions perform program control operations. The no operation instruction (NOP) may be
used to force synchronization of the internal pipelines. Table 3–8 summarizes these
instructions.
Instruction Operand Syntax
〈label〉
Bcc
DBcc Dn,〈label〉
Scc
〈label〉
BRA
〈label〉
BSR
JMP
JSR
NOP
RTD
RTR
RTS
Letters cc in the integer instruction mnemonics Bcc, DBcc, and Scc specify testing one of the following conditions:
CC — Carry clear
LS — Lower or same
CS — Carry set
LT — Less than
EQ — Equal
MI — Minus
F — Never true*
NE — Not equal
*Not applicable to the Bcc instructions.
MOTOROLA
Table 3-8. Program Control Operations
Operand Size
Integer and Floating-Point Conditional
8, 16, 32
16
〈ea〉
8
Unconditional
8, 16, 32
8, 16, 32
〈ea〉
none
〈ea〉
none
none none
#〈d〉 16
none none
none none
MC68030 USER'S MANUAL
if condition true, then PC + d → PC
if condition false, then Dn — 1 → Dn
if Dn ≠ -1, then PC + d → PC
if condition true, then 1's → destination;
else 0's → destination
PC + d → PC
SP — 4 → SP; PC→(SP); PC + d → PC
destination → PC
SP — 4 → SP; PC→ (SP); destination → PC
PC + 2 → PC
Returns
(SP) → PC; SP + 4 + d → SP
(SP) → CCR; SP + 2 → SP; (SP) → PC; SP + 4 → SP
(SP) → PC; SP + 4→ SP
GE — Greater or equal
PL — Plus
GT — Greater than
T — Always true*
HI — Higher
VC — Overflow clear
LE — -Less or equal
VS — Overflow set
Instruction Set Summary
Operation
3-11