17.4.1 Counter Bit Positions

The RTC counters support the following two counting modes:

  • Binary Mode: In Binary mode, a 43-bit counter is provided.
  • Calendar Mode: The 43 bits are allocated as following:
Table 17-4. Allocation of Bits in Calendar Mode
Counter Counts Size Bits Bits in Counter Reset Value
Seconds 0-59 6 [5:0] 0
Minutes 0-59 6 [11:6] 0
Hours 0-23 5 [16:12] 0
Day 1-31 5 [21:17] 1
Month 1-12 5 [25:22] 1
Year 0-255 8 [33:26] 0
Weekday 1-7 3 [36:34] 7
Week 1-52 6 [42:37] 1
  • Weekday, 1: Sunday, 2: Monday …. 7:Saturday
  • Reset date is Saturday 1 January 2000.
  • The leap year calculations assume the year value where 0-255 is mapped to 2000 to 2255.