MSP430FR5989: When counting radiation the time is ahead.

How are you counting time? Do you have an RTC? Do you have a crystal? Have you measured your clock frequency?

I am new to it dont have much idea about it, But, we have used external clock 32.768khz.

i think we have used 16MHZ also.

Since you probably can't share your code, can you trim your code down to a small application that shows the issue? (Often that is enough to tell you what the problem is)

Any crystal should be much better than 2%!

"Any crystal should be much better than 2%!" what you mean this?

below is part of clock in main file. 

Hi Sandip Patil,

Here are some resources to assist you since you said you're new. Our Clock example code can help you learn about the systems, this code example uses a 32 KHz crystal, and other clock examples are denoted with the msp430fr59xx_cs_0x.c format so you can look through if you want more references.

There is also this example with the real time clock which you can use as a reference for doing RTC. Run these first to make sure the device is working properly and your code follows the correct steps by referring to these examples.

Regards,

Luke

2.4% error is within the DCO specification [Ref data sheet (SLASE54C) Table 5-6].

That said, the distinction between 100.0 and 102.4 seems too much of a coincidence, and rather sounds like a small arithmetic error (off-by-one, e.g.).

Can you post your timer setup code?

Hi Bruce,

have a look at it.

I suppose this sets the TASSEL/TBSSEL field (though it doesn't say what it sets it to), and omits the dividers (ID/CCR0/TAIDEX) and mode (MC). Can you show the code that calls this? (A debugger display (Registers view) of that timer's registers might be enough to go on.)

The kinds of things I'd be looking for:

1) Trying to use ACLK (32.768kHz) for a millisecond (0.001 second vs 0.000977 second) "tick". Not only does this not work, it could produce the symptom you describe.

2) Forgetting to subtract 1 from the CCR0 value in Up mode. 

3) Rounding/truncation error in a computed timer-period (CCR0) value.

Actually, i didn't get you.

Since it seems unclear what timer is actually being displayed on the LCD, I would start right at the top, in main.c and see if I could figure that part out. I suspect that would lead to either timer.c or rtc_c.c. (The FR5989 doesn't have an RTC_B.)

I did chnaged in main.c and i found that i could make it more faster or very much slower than what we have. i just chnaged the register.

 CSCTL2 = SELA__LFXTCLK | SELS__DCOCLK | SELM__DCOCLK; // ACLK=LFXT(32kHz)|SMCLK=DCO|MCLK=DCO,

in the above line of code i changed SELA_VLOCLK   from SELA__LFXTCLK which i is nearest register in .h file but it made it more faster and then,   i also changed SELA_7 from SELA__LFXTCLK and which made it very much slower. 

I also chnaged the dividers in main.c file but it made more faster or very much slower.

The LFXTCLK (nom. 32kHz) does run quite a bit faster than the VLOCLK (nom 10kHz) [Ref data sheet (SLAS789D) Tables 5-4 and 5-7]. The VLOCLK isn't suitable for a "wall-clock" time anyway (+/-50% accurate). I don't know what SELA_7 does.

What dividers did you change?. Generally these things can be computed once the clock source and target frequency are known, but from the outside we're all just guessing

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Unsolicited: This looks suspicious:

> PJSEL1 &= ~0x0010; // 
> PJSEL0 |= 0x0010; // 

since it only enables LFXIN, not LFXOUT. For this case I would expect to see CSCTL4:LFXTBYPASS=1 [Ref User Guide (SLAU367P) Sec 3.2.2] but this code sets LFXTBYPASS=0.

What clock source are you using for your 32kHz? is it an external clock (one wire coming into PJ.4) or an external crystal (two wires coming into PJ.4 and PJ.5)? [Check the schematic if needed.] In the former case you should set LFXTBYPASS=1; for the latter you should set the 0x0030 (not 0x0010) bits in PJSEL0 [Ref data sheet Table .6-40]

we are using 32KHZ external crystal. 

CSCTL3 = DIVA__1 | DIVS__1 | DIVM__1;     here i changed divider 2 from 1 but again it was much slower.

> we are using 32KHZ external crystal. 

Then (as suggested above) you should be using 

> PJSEL0 |= 0x0030; // PJ.4/5 as LFXIN/LFXOUT per data sheet Table 6-40

I'm not quite sure how your 32kHz is working now (maybe some code you haven't posted?).

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Beyond that, I suggest you not change the CS registers any more -- leave SELA_LFXTCLK and keep all the DIVx as they were originally. As you've seen, such changes will tend to make large adjustments, and you're looking for a small adjustment.

Also, there's no mechanism for displaying a CPU clock (ACLK/SMCLK/MCLK/VLOCLK/LFXTCLK) on an LCD, rather you need to supply that clock to a timer (TimerA, TimerB, RTC), and that's where the small adjustments can be done.

What timer is being used for the LCD clock display? And how is it configured?

So i need to make this change "PJSEL0 |= 0x0030"

do you want more code to posted from main.c?

i think for LCD iRTC  is used.

How is the RTC being configured? I expect part of this would be in main.c and part in rtc_c.c.

Bruce McKenney47378 said:

I'm not quite sure how your 32kHz is working now (maybe some code you haven't posted?).

Section 3.2.8 CS Module Fail-Safe Operation of MSP430FR58xx, MSP430FR59xx, and MSP430FR6xx Family User's Guide (Rev. P) contains:

If LFXT is sourcing any system clock (ACLK, MCLK, or SMCLK) and a fault is detected, the system clock is automatically switched to LFMODCLK for its clock source.

And section 3.1 Clock System Introduction contains:

MODCLK: Internal low-power oscillator with 5-MHz typical frequency. LFMODCLK is MODCLK divided by 128.

Perhaps the frequency error is explained by the 32KHZ external crystal not being configured correction, and the internal low-tolerance LFMODCLK being used instead.

So, what should I do? what would be my right direction?

this is the piece of code before the clock_init in main.c

Sandip Patil said:

So, what should I do? what would be my right direction?

What I said earlier, create a smaller project that shows the issue and share it with us. Often, as you are doing that you discover the problem.

i found some chnage in system_timer  below line.

  System_Timers_Initialize_Timer(TMR_0,  TMR_RST_0, sys_tmrs);  // Init timer 0

here i made TMR_RST_0 macro expansion from to different values like 11, 9 . so i found that when i increased to 11 instrument time gone more slow and when made it to 9 instruyment timer gone more faster.

Have you fixed the PJSEL0 setting? Chester's observations suggest that might be the root cause.