Maxim Integrated MAX32665 - Table 18-10. RTC 32 Khz Oscillator Digital Trim Register; Table 18-11. RTC 32 Khz Oscillator Control Register

MAX32665-MAX32668 User Guide
Maxim Integrated Page 379 of 457
RTC Control Register
RTC_CTRL
[0x0010]
Bits
Field
Access
Reset
Description
1
tod_alarm_en
R/W
0*
Time-of-Day Alarm Interrupt Enable
Check the RTC_CTRL.busy flag after writing to this field to determine when the RTC
synchronization is complete.
0: Disable.
1: Enable.
*Note: Reset on POR only.
0
enable
R/W
0*
Real-Time Clock Enable
The RTC write enable (RTC_CTRL.write_en) bit must be set and RTC Busy
(RTC_CTRL.busy) must read 0 before writing to this field. After writing to this bit, check
theRTC_CTRL.busy flag for 0 to determine when the RTC synchronization is complete.
0: Disabled.
1: Enabled.
*Note: Reset on POR only.
Table 18-10. RTC 32KHz Oscillator Digital Trim Register
RTC 32KHz Oscillator Digital Trim
RTC_TRIM
[0x0014]
Bits
Field
Access
Reset
Description
31:8
vrtc_tmr
R/W
0*
VRTC Time Counter
Hardware increments this field every 32s while the RTC is enabled.
*Note: Reset on POR only.
7:0
trim
R/W
0*
RTC Trim
This field specifies the 2s complement value of the trim resolution. Each increment or
decrement of the field adds or subtracts 1ppm at each 4kHz clock value with a
maximum correction of ± 127ppm.
*Note: Reset on POR only.
Table 18-11. RTC 32KHz Oscillator Control Register
RTC Oscillator Control
RTC_OSCCTRL
[0x0018]
Bits
Field
Access
Reset
Description
31:6
-
R/W
0
Reserved for Future Use
Do not modify this field.
5
32kout
R/W
0
RTC Square Wave Output
0: Disabled.
1: Enables the 32kHz oscillator output or the external clock source is output on
square wave output pin. See Table 18-3. for configuration details.
*Note: Reset on POR only.
4
bypass
R/W
0
RTC Crystal Bypass
This field disables the RTC oscillator and allows an external clock source to be driven on
the 32KIN pin.
0: Disable bypass. RTC timebase is external 32kHz crystal.
1: Enable bypass. RTC timebase is external square wave driven on 32KIN.
*Note: Reset on POR only.
3:0
-
R/W
0b1001
Reserved for Future Use
Software must not modify this field from its current value.