Abov MC96FR364B, User Manual

Page: 35 / 194

November, 2018 Rev.1.4 35
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 MC96FR364B.
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.
Register Bank 0~3 Locations 00
H
through 1F
H
(32 bytes). ASM-51 and the device after reset default
to register bank 0. To use the other register banks the user must select them in the software (refer to
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