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6.4.2 Index Register (H:X)
Advance Information
54
The 16-bit index register allows indexed addressing of a 64-Kbyte
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
15
14
13
12
Read:
Write:
Reset:
0
0
0
0
Figure 6-3. Index Register (H:X)
The index register can serve also as a temporary data storage location.
11
10
9
8
7
6
0
0
0
0
X
X
X = Indeterminate
MC68HC(7)08KH12
Bit
5
4
3
2
1
0
X
X
X
X
X
X
Rev. 1.1
—
Freescale Semiconductor
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