HIB Registers
510
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Hibernation Module
6.5.9 HIBRTCT Register (Offset = 0x24) [reset = 0x7FFF]
Hibernation RTC Trim (HIBRTCT)
This register contains the value that is used to trim the RTC clock predivider. It represents the computed
underflow value that is used during the trim cycle. It is represented as 0x7FFF ± N clock cycles, where N
is the number of clock cycles to add or subtract every 64 seconds in RTC mode or 60 seconds in calendar
mode.
NOTE:
Except for the HIBIO and a portion of the HIBIC register, all other Hibernation module
registers are on the Hibernation module clock domain and have special timing requirements.
Software should make use of the WRC bit in the HIBCTL register to ensure that the required
timing gap has elapsed. If the WRC bit is clear, any attempted write access is ignored. See
. The HIBIO register and bits RSTWK, PADIOWK and WC of the HIBIC register
do not require waiting for write to complete. Because these registers are clocked by the
system clock, writes to these registers/bits are immediate.
Writing to registers other than the HIBCTL and HIBIM before the CLK32EN bit in the HIBCTL
register has been set may produce unexpected results.
HIBRTCT is shown in
and described in
.
Return to
Figure 6-17. HIBRTCT Register
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
RESERVED
TRIM
R-0x0
R/W-0x7FFF
Table 6-12. HIBRTCT Register Field Descriptions
Bit
Field
Type
Reset
Description
31-16
RESERVED
R
0x0
15-0
TRIM
R/W
0x7FFF
RTC Trim Value
This value is loaded into the RTC predivider every 64 seconds in
RTC counter mode.
In calendar mode, the value is loaded every 60 seconds.
It is used to adjust the RTC rate to account for drift and inaccuracy in
the clock source.
Compensation can be adjusted by software by moving the default
value of 0x7FFF up or down.
Moving the value up slows down the RTC and moving the value
down speeds up the RTC.