What is the R5F100LGA RTC clock accuracy when the internal low-speed oscillator fIL is used as the reference input source?

Low-speed on-chip oscillator
clock frequency accuracy
–15 +15 %

My question is: With so many deviations, how can it be used as a real-time clock？

可以, 如果你能接受这个时钟精度的话(–15 +15 %), 可以所谓RTC的时钟源.

–15 +15 % 数据的测试条件是

3.2.2 On-chip oscillator characteristics
(TA = –40 to +105°C, 2.4 V ≤ VDD ≤ 5.5 V, VSS = 0 V)

有没有TA=-20 到+50℃，VDD=5V的测试数据？

–15 +15 % 数据的测试条件是

3.2.2 On-chip oscillator characteristics
(TA = –40 to +105°C, 2.4 V ≤ VDD ≤ 5.5 V, VSS = 0 V)

有没有TA=-20 到+50℃，VDD=5V的测试数据？

这是全温度范围满足的精度, 不提供其他数据.