TS87C52X2 ATMEL Corporation, TS87C52X2 Datasheet - Page 10

• Manufacturer Part Number: TS87C52X2
• Description: 8-bit Microcontroller 8 Kbytes Otp
• Manufacturer: ATMEL Corporation

Dual Data Pointer
Register (Ddptr)
Figure 3. Use of Dual Pointer
10
TS8xCx2X2
7
AUXR1(A2H)
DPS
0
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).
Table 4. AUXR1: Auxiliary Register 1
Reset Value = XXXX XXX0
Not bit addressable
Number
Bit
7
-
7
6
5
4
3
2
1
0
DPH(83H) DPL(82H)
Mnemonic
GF3
DPS
6
Bit
-
0
-
-
-
-
-
DPTR1
Description
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
This bit is a general purpose user flag
Reserved
Always stuck at 0
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Data Pointer Selection
Clear to select DPTR0.
Set to select DPTR1.
DPTR0
5
-
4
-
GF3
3
External Data Memory
2
0
1
-
4184E–8051–09/02
DPS
0