Rev. C - 15 January, 2001

9

TS80C31X2

6.2 Dual Data Pointer Register Ddptr

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 external 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).

Figure 3. Use of Dual Pointer

External Data Memory

AUXR1(A2H)

DPS

DPH(83H) DPL(82H)

0

7

DPTR0

DPTR1