MC68HC08AZ60A Datasheet, PDF (101/480 Pages) Motorola, Inc – Microcontrollers

Central Processor Unit (CPU)
CPU registers
7.4.1 Accumulator (A)
The accumulator is a general-purpose 8-bit register. The CPU uses the
accumulator to hold operands and the results of arithmetic/logic
operations.
Bit 7
Read:
A
Write:
Reset:
6
5
4
3
2
Unaffected by reset
Figure 7-2. Accumulator (A)
1
Bit 0
7.4.2 Index Register (H:X)
The 16-bit index register allows indexed addressing of a 64K byte
memory space. H is the upper byte of the index register and X is the
lower byte. H:X is the concatenated 16-bit index register.
In the indexed addressing modes, the CPU uses the contents of the
index register to determine the conditional address of the operand.
Bit
Bit
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Read:
H:X
Write:
Reset: 0 0 0 0 0 0 0 0 X X X X X X X X
X = Indeterminate
Figure 7-3. Index Register (H:X)
The index register can also be used as a temporary data storage
location.
MC68HC08AZ60A — Rev 0.0
MOTOROLA
Central Processor Unit (CPU)
Advance Information
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