Data Sheet

ISM14585-L35 Specification
DOC-DS-14585-201807-3.0
Confidential Inventek Systems
Page 22
Reset by POR Only
Reset by POR or HW Reset
Reset by POR, HW or SW
Reset
BANDGAP_REG
OTPC_NWORDS_REG
The rest of the Register File
POR_PIN_REG
CLK_FREQ_TRIM_REG
POR_TIMER_REG
CLK_RADIO_REG
RF registers containing the
trimming values for the
VCO, the LNA and the I/O
capacitance
All RF calibration registers
BLE_CNTL2_REG
CLK_CTRL_REG
PMU_CTRL_REG
SYS_CTRL_REG
CLK_32K_REG_I
CLK_16M_REG_I
CLK_RCX32K_REG
TRIM_CTRL_REG
DEBUG_REG[DEBUGS_FREEZE_EN]
GP_CONTROL_REG[EM_MAP]
9.4.2 POWER-ON RESET FUNCTIONALITY
Power-On Reset functionality is available by two sources:
● Reset Pad: Reset pad is always capable of producing a Power-On Reset.
● GPIO Pin: A GPIO can be selected by the user application to act as POR source.
The time needed for the POReset pin to be active is stored in the POR_TIMER_REG.
The register field POR_TIME is a 7-bits field which holds time factor that the total time
for POR is calculated. The maximum value of the field is 0x7F. The total time for POR is
calculated by the following formula:
Total time = POR_TIME x 4096 x RC32k clock period
where RC32k clock period = 31.25μs at 25oC .
The maximum time that a POR can be performed is ~16.2 seconds at 25oC.
The RC32k clock is temperature dependent so based on the temperature span of -10oC
to 50oC, clock frequency range is calculated to be 25kHz to 39kHz. Then,
TPORcold = 13s
TPORhot = 20.8s