Im using RTC to keep track of time in my CC2640R2F device. Im working on OTA code and i need to update the firmware at a particular time in a week or a month.
How reliable and accurate is the RTC in it and how much drift I get when I run for weeks without calibrating the time? I set the device time once using Seconds_set module.
I don't have an external (LFXOSC) crystal oscillator in my circuit and Im not using internal LF RC oscillator(RCOSC_LF) either.
My clock configuration is like this in ccfg.c file,
// #define SET_CCFG_MODE_CONF_SCLK_LF_OPTION 0x0 // LF clock derived from High Frequency XOSC
// #define SET_CCFG_MODE_CONF_SCLK_LF_OPTION 0x1 // External LF clock
#define SET_CCFG_MODE_CONF_SCLK_LF_OPTION 0x2 // LF XOSC
// #define SET_CCFG_MODE_CONF_SCLK_LF_OPTION 0x3 // LF RCOSC
But there is no external oscillator in circuit. What frequency or which oscillator will the RTC use in this case? And how reliable is it?
I have read the datasheet in which it is stated to use external LF oscillator or calibrate internal LF oscillator but in my case its not the both.
I have read the following documents and threads but I dont find particular answer to my question.
Im using CCS and sdk 1.50