Rev. C - 15 January, 2001

11

TS80C54X2/C58X2

TS87C54X2/C58X2

Table 5. AUXR1: Auxiliary Register 1

Reset Value = XXXX 00X0

Not bit addressable

User software should not write 1s to reserved bits. These bits may be used in future 8051 family products to invoke new feature. In that case, the reset

value of the new bit will be 0, and its active value will be 1. The value read from a reserved bit is indeterminate.

Application

Software can take advantage of the additional data pointers to both increase speed and reduce code size, for

example, block operations (copy, compare, search ...) are well served by using one data pointer as a ’source’

pointer and the other one as a "destination" pointer.

7

6

5

4

3

2

1

0

-

-

-

-

GF3

0

-

DPS

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.

0

DPS

Data Pointer Selection

Clear to select DPTR0.

Set to select DPTR1.