AT83EB5114 Atmel Corporation, AT83EB5114 Datasheet - Page 9

• Manufacturer Part Number: AT83EB5114
• Manufacturer: Atmel Corporation

Specifications of AT83EB5114

• Max. Operating Frequency: 24 MHz
• Cpu: 8051-12C
• Max I/o Pins: 11
• Adc Channels: 6
• Adc Resolution (bits): 10
• Adc Speed (ksps): 50
• Sram (kbytes): 0.25
• Eeprom (bytes): 256
• Operating Voltage (vcc): 3.0 to 3.6
• Timers: 4
• Mask Rom (kbytes): 4
• Watchdog: Yes

Power Monitor
Description
Figure 2. Power Monitor Block Diagram
Power Monitor diagram
4311C–8051–02/08
Power-Supply
External
Vcc
Power up
Detector
The Power Monitor function supervises the evolution of the voltages feeding the micro-
controller, and if needed, suspends its activity when the detected value is out of
specification.
It warrants proper startup when AT8xEB5114 is powered up and prevents code execu-
tion errors when the power supply becomes lower than the functional threshold.
This chapter describes the functions of the power monitor.
In order to startup and to properly maintain the microcontroller operation, Vcc has to be
stabilized in the Vcc operating range and the oscillator has to be stabilized with a nomi-
nal amplitude compatible with logic threshold.
In order to be sure the oscillator is stabilized, there is an internal counter which main-
tains the reset during 1024 clock periods in case the oscillator selected is the OSC A
and 64 clock periods in case the oscillator used is OSC B or OSC C.
This control is carried out during three phases: the power-up, normal operation and
stop. In accordance with the following requirements:
•
•
The Power Monitor monitors the power-supply in order to detect any voltage drops
which are not in the target specification. The power monitor block verifies two kinds of
situation that may occur:
•
•
Figure 2 shows some configurations which can be handled by the Power Monitor.
it guarantees an operational Reset when the microcontroller is powered-up, and
a protection if the power supply goes below minimum operating Vcc
during the power-up condition, when Vcc reaches the product specification,
during a steady-state condition, when Vcc is at nominal value but disturbed by any
undesired voltage drops.
Power Fail
Detector
Internal RESET
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