Renesas R5S72621 User Manual
Section 33 Power-Down Modes
Page 1818 of 2108
R01UH0134EJ0400 Rev. 4.00
Sep
24,
2014
SH7262 Group, SH7264 Group
33.4
Usage Notes
33.4.1
Usage Notes on Setting Registers
When writing to the registers related to power-down modes, note the following.
When writing to the register related to power-down modes, the CPU, after executing a write
instruction, executes the next instruction without waiting for the write operation to complete.
instruction, executes the next instruction without waiting for the write operation to complete.
Therefore, to reflect the change specified by writing to the register while the next instruction is
executed, insert a dummy read of the same register between the register write instruction and the
next instruction.
executed, insert a dummy read of the same register between the register write instruction and the
next instruction.
33.4.2
Usage Notes when the Realtime Clock is not Used
When the realtime clock is not used, set the MSTP30 bit in STBCR3 to 1 after setting the bits in
registers of the realtime clock shown below.
registers of the realtime clock shown below.
Set the RTCEN bit in the control register 2 (RCR2) to 0.
Set the RCKSEL[1:0] bits in the control register 5 (RCR5) to 00.
Set the RCKSEL[1:0] bits in the control register 5 (RCR5) to 00.