at32uc3b0512-z2ues ATMEL Corporation, at32uc3b0512-z2ues Datasheet - Page 48

• Manufacturer Part Number: at32uc3b0512-z2ues
• Description: 32-bit Avr Microcontroller
• Manufacturer: ATMEL Corporation

9.5.11.3
9.5.12
32059J–12/2010
Calibration registers
External Reset
See Electrical Characteristics for parametric details.
The external reset detector monitors the state of the RESET_N pin. By default, a low level on
this pin will generate a reset.
The Power Manager controls the calibration of the RC oscillator, voltage regulator, bandgap
voltage reference through several calibration registers.
Those calibration registers are loaded after a Power On Reset with default values stored in fac-
tory-programmed flash fuses.
Although it is not recommended to override default factory settings, it is still possible to override
these default values by writing to those registers. To prevent unexpected writes due to software
bugs, write access to these registers is protected by a “key”. First, a write to the register must be
made with the field “KEY” equal to 0x55 then a second write must be issued with the “KEY” field
equal to 0xAA
AT32UC3B
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