HD6417727BP160CV Datasheet, PDF (537/1098 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH™ RISC engine Family/ SH7700 Series

Section 16 Realtime Clock (RTC)
16.4.3 Using the ADJ Bit in the Real Time Clock (RTC)
(1) Description
The maximum amount of time from when the ADJ bit in RCR2 of the RTC is set to 1 and when
the value read from the second counter (RSECCNT) is reflected is approximately 91.6 µs (the
time required for pin of the EXTAL2 to connect to the 32.768 kHz crystal resonator). Note that the
second counter itself performs a 30-second adjustment when the ADJ bit is set to 1, so the above
delay causes no problems with the functioning of the RTC.
(2) Precautions
If it is necessary to ensure that the 30-second adjustment triggered by the ADJ bit in RCR2 of the
RTC is properly read and its value reflected, the second counter should not be read until a
minimum of approximately 91.6 µs has passed following the setting of the ADJ bit.
Rev.6.00 Mar. 27, 2009 Page 479 of 1036
REJ09B0254-0600