39.5.2 Reset Controller Specifications

Table 39-15. Reset, WDT, Oscillator Start-up Timer, Power-up Timer, Brown-out Detector Specifications
Sym.DescriptionMin.Typ. Max.UnitsConditions
tRSTRESET pin pulse-width low to ensure reset(1)2.5——μs
RRST_UPRESET pin pull-up resistor—35—kΩ
TWDTWatchdog Timer time-out period—500—ms1:512 Prescaler
TSUTPower-up timer period—64—msSUT = 0x07
TOSTOscillator start-up timer period(2)—1024—cycles
VBODBrown-out Detect voltage(3)—

1.90

2.45

2.7

2.85

—

V

V

V

V

BODLEVEL0

BODLEVEL1

BODLEVEL2

BODLEVEL3

VBOD_HYSBrown-out Detect hysteresis—44—mV
tBOD_STBrown-out Detect start-up time—1.9—μs
tBOD_128HZBOD response time Sampling Mode @128 Hz—7.81—msSAMPFREQ=0
tBOD_32HZBOD response time Sampling Mode @32 Hz—31.25—msSAMPFREQ=1
tBOD_RSTBrown-out reset response time—3—μs
Note:
  1. These values are based on simulation and not covered by production test limits.
  2. By design, the Oscillator Start-up Timer (TOST) counts the first 1024 cycles, independent of frequency.
  3. To ensure these voltage tolerances, VDD and GND must be capacitively decoupled as close to the device as possible. 0.1 μF and 0.01 μF values in parallel are recommended.
Table 39-16. Voltage Level Monitor Threshold Characteristics
SymbolDescriptionMin.Typ. Max.UnitsConditions
VDETVoltage detection threshold—5—% of BOD ThresholdVLMLVL = 0x01
—15—% of BOD ThresholdVLMLVL = 0x02
—25—% of BOD ThresholdVLMLVL = 0x03