Datasheet
Chapter 7 Central Processor Unit (S08CPUV3)
MC9S08EL32 Series and MC9S08SL16 Series Data Sheet, Rev. 3
Freescale Semiconductor 103
7.4.5 BGND Instruction
The BGND instruction is new to the HCS08 compared to the M68HC08. BGND would not be used in
normal user programs because it forces the CPU to stop processing user instructions and enter the active
background mode. The only way to resume execution of the user program is through reset or by a host
debug system issuing a GO, TRACE1, or TAGGO serial command through the background debug
interface.
Software-based breakpoints can be set by replacing an opcode at the desired breakpoint address with the
BGND opcode. When the program reaches this breakpoint address, the CPU is forced to active
background mode rather than continuing the user program.
7.5 HCS08 Instruction Set Summary
Table 7-2 provides a summary of the HCS08 instruction set in all possible addressing modes. The table
shows operand construction, execution time in internal bus clock cycles, and cycle-by-cycle details for
each addressing mode variation of each instruction.
Table 7-2. Instruction Set Summary (Sheet 1 of 9)
Source
Form
Operation
Address
Mode
Object Code
Cycles
Cyc-by-Cyc
Details
Affect
on CCR
V 1 1 HI N Z C
ADC #opr8i
ADC opr8a
ADC opr16a
ADC oprx16,X
ADC oprx8,X
ADC ,X
ADC oprx16,SP
ADC oprx8,SP
Add with Carry
A ← (A) + (M) + (C)
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
A9
B9
C9
D9
E9
F9
9E D9
9E E9
ii
dd
hh ll
ee ff
ff
ee ff
ff
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
11 –
ADD #opr8i
ADD opr8a
ADD opr16a
ADD oprx16,X
ADD oprx8,X
ADD ,X
ADD oprx16,SP
ADD oprx8,SP
Add without Carry
A ← (A) + (M)
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
AB
BB
CB
DB
EB
FB
9E DB
9E EB
ii
dd
hh ll
ee ff
ff
ee ff
ff
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
11 –
AIS
#op
r8i
Add Immediate Value (Signed) to
Stack Pointer
SP ← (SP) + (M)
IMM A7 ii 2 pp –11– ––––
AIX #opr8i
Add Immediate Value (Signed) to
Index Register (H:X)
H:X ← (H:X) + (M)
IMM AF ii 2 pp –11– ––––
AND #opr8i
AND opr8a
AND opr16a
AND oprx16,X
AND oprx8,X
AND ,X
AND oprx16,SP
AND oprx8,SP
Logical AND
A ← (A) & (M)
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
A4
B4
C4
D4
E4
F4
9E D4
9E E4
ii
dd
hh ll
ee ff
ff
ee ff
ff
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
011–
–
–
