AT89C51AC3-SLSIM Atmel, AT89C51AC3-SLSIM Datasheet - Page 27

• Manufacturer Part Number: AT89C51AC3-SLSIM
• Description: IC 8051 MCU FLASH 64K 44PLCC
• Manufacturer: Atmel
• Series: 89Cr

Specifications of AT89C51AC3-SLSIM

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 60MHz
• Connectivity: UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 36
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 2.25K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-PLCC
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Power Monitor
Description
Figure 14. Power Monitor Block Diagram
4383D–8051–02/08
The POR/PFD function monitors the internal power-supply of the CPU core memories
and the peripherals, and if needed, suspends their activity when the internal power sup-
ply falls below a safety threshold. This is achieved by applying an internal reset to them.
By generating the Reset the Power Monitor insures a correct start up when
AT89C51CC03 is powered up.
In order to startup and maintain the microcontroller in correct operating mode, V
to be stabilized in the V
nominal amplitude compatible with logic level VIH/VIL.
These parameters are controlled during the three phases: power-up, normal operation
and power going down. See Figure 14.
Note:
The Voltage regulator generates a regulated internal supply for the CPU core the mem-
ories and the peripherals. Spikes on the external Vcc are smoothed by the voltage
regulator.
The Power fail detect monitor the supply generated by the voltage regulator and gener-
ate a reset if this supply falls below a safety threshold as illustrated in the Figure 15.
RST pin
XTAL1
1. Once XTAL1 high and low levels reach above and below VIH/VIL a 1024 clock period
delay will extend the reset coming from the Power Fail Detect. If the power falls below
the Power Fail Detect thresthold level, the reset will be applied immediately.
PCA
Watchdog
Voltage Regulator
Power Fail Detect
Power On Reset
(1)
Hardware
Watchdog
VCC
CC
operating range and the oscillator has to be stabilized with a
Regulated
Supply
Internal Reset
Peripherals
CPU core
Memories
CC
has
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