CPU12
INSTRUCTION GLOSSARY
MOTOROLA
REFERENCE MANUAL
6-49
Operation:
(SP) – $0002
⇒
SP
RTN
H
: RTN
L
⇒
M
(SP)
: M
(SP
+
1)
(PC)
+
Rel
⇒
PC
Description:
Sets up conditions to return to normal program flow, then transfers con-
trol to a subroutine. Uses the address of the instruction after the BSR as
a return address.
Decrements the SP by two, to allow the two bytes of the return ad-
dress to be stacked.
Stacks the return address (the SP points to the high order byte of the
return address).
Branches to a location determined by the branch offset.
Subroutines are normally terminated with an RTS instruction, which re-
stores the return address from the stack.
Condition Codes and Boolean Formulas:
None affected.
Addressing Modes, Machine Code, and Execution Times:
BSR
Branch to Subroutine
BSR
S
X
H
I
N
Z
V
C
–
–
–
–
–
–
–
–
Source Form
Address Mode
Object Code
Cycles
Access Detail
BSR
rel8
REL
07 rr
4
PPPS
Summary of Contents for CPU12
Page 8: ...MOTOROLA CPU12 viii REFERENCE MANUAL ...
Page 14: ...MOTOROLA INTRODUCTION CPU12 1 4 REFERENCE MANUAL ...
Page 20: ...MOTOROLA OVERVIEW CPU12 2 6 REFERENCE MANUAL ...
Page 38: ...MOTOROLA INSTRUCTION QUEUE CPU12 4 6 REFERENCE MANUAL ...
Page 300: ...MOTOROLA DEVELOPMENT AND DEBUG SUPPORT CPU12 8 16 REFERENCE MANUAL ...
Page 338: ...MOTOROLA MEMORY EXPANSION CPU12 10 8 REFERENCE MANUAL ...
Page 364: ...MOTOROLA INSTRUCTION REFERENCE CPU12 A 26 REFERENCE MANUAL ...
Page 386: ...MOTOROLA HIGH LEVEL LANGUAGE SUPPORT CPU12 C 6 REFERENCE MANUAL ...
Page 438: ...MOTOROLA SUMMARY OF CHANGES CPU12 S 2 REFERENCE MANUAL ...
Page 439: ......