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CHAPTER 18 INSTRUCTION SET
237
<4> Note 1
The data buffer is assigned to addresses 0CH, 0DH, 0EH, and 0FH in bank 0 for the data memory, regardless
of the bank register value.
Note 2
Up to 16 bits in the data buffer are available. When a peripheral circuit is accessed by the GET instruction,
the number of bits, by which the circuit is to be accessed, differs depending on the circuit. For example,
if the GET instruction is executed to access a peripheral circuit, which should be accessed in 8-bit units, data
is stored in the lower 8 bits for the data buffer DBF (DBF1, DBF0).
Data buffer
DBF3
Retain
DBF2
Retain
DBF1
b
7
DBF0
b
0
GET
Actual bits
b
7
b
0
Data of peripheral
hardware
Bank 0
Column address
System register
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
Row address
DBF
Bank 0
Column address
System register
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
DBF
Row address
1
2
Peripheral
circit
12H
SIOSFR
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