Datasheet

Data Sheet ADE5166/ADE5169/ADE5566/ADE5569
Rev. D | Page 85 of 156
MEMORY OVERVIEW
The ADE5166/ADE5169/ADE5566/ADE5569 contain three
memory blocks, as follows:
• 62 kB of on-chip Flash/EE program and data memory
• 256 bytes of general-purpose RAM
• 2 kB of extended internal RAM (XRAM)
The 256 bytes of general-purpose RAM share the upper 128 bytes
of its address space with the SFRs. All of the memory spaces are
shown in Figure 81. The addressing mode specifies which
memory space to access.
General-Purpose RAM
General-purpose RAM resides in Memory Location 0x00
through Memory Location 0xFF. It contains the register banks.
11
10
01
00
RESET VALUE OF
STACK POINTER
FOUR BANKS OF EIGHT
REGISTERS R0 TO R7
BIT-ADDRESSABLE
(BIT ADDRESSES)
GENERAL-PURPOSE
AREA
BANKS
SELECTED
VIA
BITS IN PSW
0x
00
0x 08
0x 10
0x 18
0x 20
0x 30
0x 07
0x 0F
0x 17
0x 1F
0x 2F
0x 7F
07411-058
Figure 83. Lower 128 Bytes of Internal Data Memory
Address 0x80 through Address 0xFF of general-purpose RAM
are shared with the SFRs. The mode of addressing determines
which memory space is accessed, as shown in Figure 84.
ACCESSIBLE BY
INDIRECT ADDRESSING
ONLY
ACCESSIBLE BY
DIRECT AND
INDIRECT ADDRESSING
0×FF
GENERAL-PURPOSE RAM
0×00
0×80
0×7F
ACCESSIBLE BY
DIRECT ADDRESSING
ONLY
SPECIFIC FUNCTION REGISTERS (SFRs)
07411-120
Figure 84. General-Purpose RAM and SFR Memory Address Overlap
Both direct and indirect addressing can be used to access general-
purpose RAM from Address 0x00 through Address 0x7F, but
indirect addressing must be used to access general-purpose
RAM with addresses in the range from 0x80 through 0xFF
because they share the same address space with the SFRs.
The 8052 core also has the means to access individual bits of
certain addresses in the general-purpose RAM and special function
memory spaces. The individual bits of general-purpose RAM,
Address 0x20 to Address 0x2F, can be accessed through Bit
Address 0x00 to Bit Address 0x7F. The benefit of bit addressing is
that the individual bits can be accessed quickly, without the
need for bit masking, which takes more code memory and
execution time. The bit addresses for General-Purpose RAM
Address 0x20 through General-Purpose RAM Address 0x2F
can be seen in Figure 85.
BYTE
ADDRESS BIT ADDRESSES (HEXA)
0x2F
0x2E
0x2D
0x2C
0x2B
0x2A
0x29
0x28
0x27
0x26
0x25
0x24
0x23
0x22
0x21
0x20
7F
77
6F
67
5F
57
4F
47
3F
37
2F
27
1F
17
0F
07
7E
76
6E
66
5E
56
4E
46
3E
36
2E
26
1E
16
0E
06
7D
75
6D
65
5D
55
4D
45
3D
35
2D
25
1D
15
0D
05
7C
74
6C
64
5C
54
4C
44
3C
34
2C
24
1C
14
0C
04
7B
73
6B
63
5B
53
4B
43
3B
33
2B
23
1B
13
0B
03
7A
72
6A
62
5A
52
4A
42
3A
32
2A
22
1A
12
0A
02
79
71
69
61
59
51
49
41
39
31
29
21
19
11
09
01
78
70
68
60
58
50
48
40
38
30
28
20
18
10
08
00
07411-060
Figure 85. Bit-Addressable Area of General-Purpose RAM
Bit addressing can be used for instructions that involve Boolean
variable manipulation and program branching (see the Instruction
Set section).
Special Function Registers (SFRs)
Special function registers are registers that affect the function
of the 8052 core or its peripherals. These registers are located
in RAM at Address 0x80 through Address 0xFF. They are
accessible only through direct addressing, as shown in Figure 84.
The individual bits of some of the SFRs can be accessed for use
in Boolean and program branching instructions. These SFRs are
labeled as bit addressable, and the bit addresses are given in
Table 15.
Extended Internal RAM (XRAM)
The ADE5166/ADE5169/ADE5566/ADE5569 provide 2 kB of
extended on-chip RAM. No external RAM is supported. This
RAM is located in Address 0x00 through Address 0x7FF in the
extended RAM space. To select the extended RAM memory
space, the extended indirect addressing modes are used.
2kB OF
EXTENDED INTERNAL
RAM (XRAM)
0x7FF
0x00
07411-061
Figure 86. Extended Internal RAM (XRAM) Space