Siemens C500 User Manual page 7

Figure 1-2 shows the configuration of the three basic internal RAM areas. The lower data RAM is
located in the address range 00 H - 7F H and can be addressed directly (e.g. MOV A,direct) or
indirectly (e.g. MOV A,@R0 with address in R0). A bit-addressable area of 128 free programmable,
direct addressable bits is located at byte addresses 20 H - 2F H of the lower data RAM. Bit 0 of the
internal data byte at 20 H has the bit address 00 H while bit 7 of the internal data byte at 2F H has the
bit address 7F H . The lower 32 locations of the internal lower data RAM are assigned to four banks
with eight general purpose registers (GPRs) each. Only one of these banks can be enabled at a
time to be used as general purpose registers.
FF H
F8 H FF FE FD FC FB FA F9 F8
F0 F7 F6 F5 F4
H
E8 EF EE ED EC
H
E0 E7 E6 E5 E4
H
D8
DF DE DD DC
H
D0
D7 D6 D5 D4
H
C8
CF CE CD CC
H
C0
C7 C6 C5 C4
H
B8 BF BE BD BC
H
B0 B7 B6 B5 B4
H
A8 AF AE AD AB
H
A0 A7 A6 A5 A4
H
98
9F 9E 9D 9B
H
90 97 96 95 94
H
88 8F 8E 8D 8B
H
80 87 86 85 84
H
Internal SFR Area
(direct addressable)
128
1) This internal RAM area is optional. Some low-end C500 family microcontrollers don't
provide this internal RAM area.
Figure 1-2
Internal Data Memory Organization
Semiconductor Group
FF
H
F3 F2 F1 F0
EB EA E9 E8
E3 E2 E1 E0
DB DA D9 D8
80
H
7F
D3 D2 D1 D0
H
CB CA C9 C8
C3 C2 C1 C0
BB BA B9 B8
B3 B2 B1 B0
AC AA A8 A9
00 H
A3 A2 A1 A0
9C 9A 98 99
93 92 91 90
8A 88 89
8C
83 82 81 80
Byte
7F H
Upper
Internal Data
30
RAM
2F H
2E H
1)
2D H
(indirect
addressable)
2C H
2B H
128 Byte
2A H
29 H
28 H
27 H
26 H
Lower
25 H
Internal Data
RAM
24 H
23 H
(indirect & direct
22 H
addressable)
21 H
128 Byte
20
1F H
18
17
10
0F
08 H
07
06
05
04
03
02
01
00
1-4
Fundamental Structure
C500 Family
~ ~
RAM Area
H
7F 7E 7D 7C 3B 7A 79 78
77 76 75 74 73 72 71 70
6F 6E 6D 6B 6A 69 68
6C
67 66 65 64 63 62 61 60
5F 5E 5D 5C 5B 5A 59 58
57 55
56 54 53 52 51 50
4F 4E 4D 4C 4B 4A 49 48
46 45 43 40
47 44 42 41
3F 3E 3D 3C 3B 3A 39 38
37 36 35 34 33 32 31 30
2F 2E 2D 2C 2B 2A 29 28
27 26 25 24 23 22 21 20
1F 1E 1D 1C 1B 1A 19 18
17 16 15 14 13 12 11 10
0F 0E 0D 0C 0B 0A 09 08
07 06 05 04 03 02 01 00
H
Registerbank 3
H
H
Registerbank 2
H
H
Registerbank 1
R7
H
R6
H
R5
H
R4
H
R3
H
R2
H
R1
H
R0
H
MCD02767
~ ~
1998-04-01