MC68HC711xxxx Motorola, MC68HC711xxxx Datasheet - Page 76

• Manufacturer Part Number: MC68HC711xxxx
• Description: Microcontrollers
• Manufacturer: Motorola

Central Processor Unit (CPU)
4.2.5 Program Counter (PC)
Data Sheet
76
JSR, JUMP TO SUBROUTINE
INDEXED, X
BSR, BRANCH TO SUBROUTINE
RTS, RETURN FROM
SUBROUTINE
INDEXED, Y
INDEXED, Y
DIRECT
PC
PC
MAIN PROGRAM
MAIN PROGRAM
$8D = BSR
RTN
RTN
RTN
RTN
$39 = RTS
PC
PC
PC
PC
NEXT MAIN INSTR.
NEXT MAIN INSTR.
NEXT MAIN INSTR.
NEXT MAIN INSTR.
MAIN PROGRAM
MAIN PROGRAM
MAIN PROGRAM
MAIN PROGRAM
$BD = PRE
$AD = JSR
$AD = JSR
$9D = JSR
$18 = PRE
The program counter, a 16-bit register, contains the address of the next instruction
to be executed. After reset, the program counter is initialized from one of six
possible vectors, depending on operating mode and the cause of reset. See
Table
dd
hh
ff
ff
ll
Test or Boot
SP–2
SP–1
SP+1
SP+2
Normal
4-1.
Mode
SP
SP
7
7
Figure 4-2. Stacking Operations
SP–2
SP–1
STACK
STACK
SP
RTN
RTN
RTN
RTN
7
H
H
L
L
Central Processor Unit (CPU)
POR or RESET Pin
STACK
RTN
RTN
0
0
Table 4-1. Reset Vector Comparison
H
L
$BFFE, F
$FFFE, F
0
LEGEND:
RTN
RTN
RTN = ADDRESS OF NEXT INSTRUCTION IN MAIN PROGRAM TO
RTI, RETURN FROM INTERRUPT
SWI, SOFTWARE INTERRUPT
WAI, WAIT FOR INTERRUPT
dd = 8-BIT DIRECT ADDRESS ($0000–$00FF) (HIGH BYTE ASSUMED
hh = HIGH-ORDER BYTE OF 16-BIT EXTENDED ADDRESS
H
ff = 8-BIT POSITIVE OFFSET $00 (0) TO $FF (255) IS ADDED TO INDEX
L
ll = LOW-ORDER BYTE OF 16-BIT EXTENDED ADDRESS
rr= SIGNED RELATIVE OFFSET $80 (–128) TO $7F (+127) (OFFSET
= MOST SIGNIFICANT BYTE OF RETURN ADDRESS
= LEAST SIGNIFICANT BYTE OF RETURN ADDRESS
= STACK POINTER POSITION AFTER OPERATION IS COMPLETE
PC
PC
PC
BE EXECUTED UPON RETURN FROM SUBROUTINE
TO BE $00)
RELATIVE TO THE ADDRESS FOLLOWING THE MACHINE CODE
OFFSET BYTE)
INTERRUPT ROUTINE
MAIN PROGRAM
MAIN PROGRAM
$3E = WAI
$3F = SWI
Clock Monitor
$3B = RTI
$BFFC, D
$FFFC, D
SP+1
SP+2
SP+3
SP+4
SP+5
SP+6
SP+7
SP+8
SP+9
SP–9
SP–8
SP–7
SP–6
SP–5
SP–4
SP–3
SP–2
SP–1
M68HC11E Family — Rev. 5
SP
SP
7
7
COP Watchdog
$FFFA, B
$BFFA, B
STACK
STACK
ACCB
ACCA
RTN
ACCB
ACCA
RTN
RTN
RTN
CCR
CCR
IX
IY
IX
IY
IX
IY
IX
IY
H
H
H
H
L
L
L
L
H
H
L
L
MOTOROLA
0
0