AT89LV55-12AC Atmel, AT89LV55-12AC Datasheet - Page 16

• Manufacturer Part Number: AT89LV55-12AC
• Description: IC 8051 MCU FLASH 20K 44TQFP
• Manufacturer: Atmel
• Series: 89LVr

Specifications of AT89LV55-12AC

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 12MHz
• Connectivity: UART/USART
• Number Of I /o: 32
• Program Memory Size: 20KB (20K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 6 V
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 44-TQFP, 44-VQFP
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: UART
• Maximum Clock Frequency: 12 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3 bit
• Operating Supply Voltage: 2.7 V to 6 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -
• Peripherals: -
• Lead Free Status / Rohs Status: No

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
0811E–MICRO–9/08
PORT3
Data
Data
Data
Data