User’s Manual
M68HC12A4EVB Evaluation Board — Rev. 1
70
Operation
MOTOROLA
Operation
<
RegisterName>
Modify Register Value
Syntax:
<
RegisterName> <RegisterValue>
Where:
<
RegisterName>
is one of the CPU12 registers listed in
Table 3-3
.
<
RegisterValue>
is an 8- or 16-bit hexadecimal number.
Each of the fields in the condition code register (CCR) may be modified by
using the bit names in
Table 3-4
.
Table 3-3. CPU12 Registers
Register Name
Description
Legal Range
PC
Program counter
$0 to $FFFF
SP
Stack pointer
$0 to $FFFF
X
X-index register
$0 to $FFFF
Y
Y-index register
$0 to $FFFF
A
A accumulator
$0 to $FF
B
B accumulator
$0 to $FF
D
D accumulator (A:B)
$0 to $FFFF
CCR
Condition code register
$0 to $FF
Table 3-4. Condition Code Register Bits
CCR Bit Name
Description
Legal Values
S
STOP enable
0 or 1
H
Half carry
0 or 1
N
Negative flag
0 or 1
Z
Zero flag
0 or 1
V
Two’s complement overflow flag
0 or 1
C
Carry flag
0 or 1
IM
IRQ interrupt mask
0 or 1
XM
XIRQ interrupt mask
0 or 1
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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