HD6417750 Datasheet, PDF (338/1039 Pages) Renesas Technology Corp – SuperH RISC engine

The procedure for setting the time while the clock is running is shown in (b). This method is
useful for modifying only certain counter values (for example, only the second data or hour data).
If a carry occurs during the write operation, the write data is automatically updated and there will
be an error in the set data. The carry flag should therefore be used to check the write status. If the
carry flag (RCR1.CF) is set to 1, the write must be repeated.
The interrupt function can also be used to determine the carry flag status.
11.3.2 Time Reading Procedures
Figure 11.3 shows examples of the time reading procedures.
Rev. 6.0, 07/02, page 286 of 986