MC96FR116C
November, 2018 Rev.1.8
41
8.2.1 Indirect Address Area
Note that in Figure 8.2 the SFRs and the indirect address RAM have the same addresses (80
H
~FF
H
).
Nevertheless, they are two separate areas and accessed in two different ways.
For example the instruction
MOV
80H, #0AAH
writes 0AA
H
to Port 0 which is one of the SFRs and the instruction
MOV
R0, #80H
MOV
@R0, #0BBH
writes 0BB
H
in location 80
H
of data RAM. Thus, after execution of both of the above instructions Port 0
will contain 0AA
H
and location 80
H
of the RAM will contain 0BB
H
.
Note that stack operations are examples of indirect addressing, so the upper 128 bytes of data RAM
are available as stack space in MC96FR116C.
8.2.2 Direct And Indirect Address Area
The 128 bytes of RAM which can be accessed by both direct and indirect addressing can be divided
into 3 segments as listed below and shown in Figure 8.3.
00
01
02
03
04
05
06
07
08
09
0A
0B
0C
0D
0E
0F
10
11
12
13
14
15
16
17
18
19
1A
1B
1C
1D
1E
1F
20
21
22
23
24
25
26
27
28
29
2A
2B
2C
2D
2E
2F
30
31
32
33
34
35
36
37
38
39
3A
3B
3C
3D
3E
3F
40
41
42
43
44
45
46
47
48
49
4A
4B
4C
4D
4E
4F
50
51
52
53
54
55
56
57
58
59
5A
5B
5C
5D
5E
5F
60
61
62
63
64
65
66
67
68
69
6A
6B
6C
6D
6E
6F
70
71
72
73
74
75
76
77
78
79
7A
7B
7C
7D
7E
7F
R5
R4
R3
R2
R1
R0
R6
R7
2FH
Register bank 0
(8 bytes)
Register bank 1
(8 bytes)
Register bank 2
(8 bytes)
Register bank 3
(8 bytes)
Bit addressable
General purpose
register
20H
18H
17H
10H
0FH
08H
07H
00H
30H
7FH
1FH
80 bytes
16 bytes
(128bits)
8 bytes
8 bytes
8 bytes
8 bytes
Figure 8-3 Lower 128 Byte of IRAM