at89lv55 ATMEL Corporation, at89lv55 Datasheet - Page 16

• Manufacturer Part Number: at89lv55
• Description: At89lv55 8-bit Microcontroller With 20k Bytes Flash
• Manufacturer: ATMEL Corporation

15. Power-down Mode
Table 15-1.
16
Mode
Idle
Idle
Power-down
Power-down
AT89LV55
Status of External Pins During Idle and Power-down Modes
Program Memory
Internal
External
Internal
External
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. The only exit from power-down is a hardware
reset. Reset redefines the SFRs but does not change the on-chip RAM. The reset should not be
activated before V
enough to allow the oscillator to restart and stabilize.
Figure 15-1. Oscillator Connections
Note:
Figure 15-2. External Clock Drive Configuration
C1, C2 = 30 pF ± 10 pF for Crystals
= 40 pF ± 10 pF for Ceramic Resonators
CC
is restored to its normal operating level and must be held active long
ALE
1
1
0
0
PSEN
1
1
0
0
PORT0
Float
Float
Data
Data
PORT1
Data
Data
Data
Data
Address
PORT2
Data
Data
Data
0811D–MICRO–3/06
PORT3
Data
Data
Data
Data