MSP430F6779: I have a question about RTC.

Part Number: MSP430F6779

Hello,

I have a question about RTC.

The following description is on page 570 of slau208p.pdf.

"Alternatively, the counter register can be read multiple times while operating, and a majority vote taken in software to determine the correct reading. "

Q1
How many times is it appropriate for multiple times here?

Q2
What is the interval to read?

Regards,
DA

over 9 years ago

0 Caleb Overbay over 9 years ago

TI__Genius 15370 points

Hi Da,

I recommend taking a look at these similar E2E posts and let me know if they answer your questions:
e2e.ti.com/.../322115
e2e.ti.com/.../2201647

Best regards,
Caleb Overbay

0 Caleb Overbay over 8 years ago

TI__Genius 15370 points

Hi Da,

Were the above posts able to answer your questions?

Best regards,
Caleb Overbay

0 da over 8 years ago in reply to Caleb Overbay

Expert 2780 points

I have referred, but I think that it is not the answer.

I thought as follows, is there a problem?

The RTC can read when RTCRDY is 1.
During the period when RTCRDY is 0, it is + -128 / 32768 [s].

+ - 128/32768 [s] = 7.8 [ms]

case 1. When RTCRDY is not used
The register reading interval is read at 7.8 ms.
It is OK to read in 3 times.

case 2. When using RTCRDY
When RTCRDY = 1, read registers and check RTCRDY again.
When RTCRDY = 1, it is regarded as valid.
If RTCRDY = 0, the reading operation is repeated after 7.8 ms.

Regards,
DA

0 Caleb Overbay over 8 years ago in reply to da

TI__Genius 15370 points

Hi Da,

You're logic looks good to me. When using the RTCRDY bit according to the recommendations of the user's guide, you get nearly a complete second to read the RTC registers.

When not using the RTCRDY bit, taking three readings 7.8ms apart and using the two that are equal to each other will result in a correct reading.

Best regards,
Caleb Overbay

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MSP430F6779: I have a question about RTC.