AT80C32X2-RLTUV Ver la hoja de datos (PDF) - Atmel Corporation
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AT80C32X2-RLTUV Datasheet PDF : 55 Pages
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Dual Data Pointer
Register (Ddptr)
Figure 3. Use of Dual Pointer
The additional data pointer can be used to speed up code execution and reduce code
size in a number of ways.
The dual DPTR structure is a way by which the chip will specify the address of an exter-
nal data memory location. There are two 16-bit DPTR registers that address the external
memory, and a single bit called
DPS = AUXR1/bit0 (See Table 5.) that allows the program code to switch between them
(Refer to Figure 3).
External Data Memory
7
0
DPS
AUXR1(A2H)
DPTR1
DPTR0
DPH(83H) DPL(82H)
Table 4. AUXR1: Auxiliary Register 1
7
6
5
4
3
2
1
-
-
-
-
GF3
0
-
Bit
Number
Bit
Mnemonic Description
7
-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
6
-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
5
-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
4
-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
3
GF3 This bit is a general purpose user flag
2
0
Reserved
Always stuck at 0
1
-
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Data Pointer Selection
0
DPS Clear to select DPTR0.
Set to select DPTR1.
Reset Value = XXXX XXX0
Not bit addressable
0
DPS
10 TS8xCx2X2
4184I–8051–02/08
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