20

2601C–MICRO–06/08

AT89LS52

16. Power-down Mode

In the Power-down mode, the oscillator is stopped, and the instruction that invokes Power-down

is the last instruction executed. The on-chip RAM and Special Function Registers retain their

values until the Power-down mode is terminated. Exit from Power-down mode can be initiated

either by a hardware reset or by activation of an enabled external interrupt (INT0 or INT1). Reset

redefines the SFRs but does not change the on-chip RAM. The reset should not be activated

before V

the oscillator to restart and stabilize.

Figure 16-1. Oscillator Connections

Note:

C1, C2 = 30 pF

± 10 pF for Crystals

= 40 pF

± 10 pF for Ceramic Resonators

Figure 16-2. External Clock Drive Configuration

C2

XTAL2

GND

XTAL1

C1

XTAL2

XTAL1

GND

NC

EXTERNAL

OSCILLATOR

SIGNAL