Indikacia zastavenia RTC, was: pamet "na chvili"

[Jan Waclawek]

Zaujimave, dakujem.

Skoda ze neviem najst nic blizsie o tom, ako as presne to "oscillator fail"
detekuje. Z tej formulacie mi to znie tak, ze sa porovnava ten oscilator s
nejakym vnutornym RC oscilatorom, nieco ako je v novsich STM32 "Clock
security system on LSE" - ale ten pri vypnutom "normalnom" napajani
nefunguje. Ak v LPC17xx toto funguje aj pri vypnutom napajani na pokles
VBAT do bodu, kde zlyha oscilator, tak potom je to super.

Inak stiahol som si LPC176xx datasheet a tam som nasiel v Table 8:
Vi(VBAT) input voltage on pin VBAT  -- min 2.1V

a k tomu je pod tabulkou tento footnote:
[5] The RTC typically fails when V i(VBAT) drops below 1.6 V

wek

----- Original Message ---------------

Subject: Re: Indikacia zastavenia RTC, was: pamet "na chvili"
   From: Lubor Otta <butan na centrum.cz>
   Date: Sat, 24 Aug 2024 13:07:28 +0200
     To: <hw-list na list.hw.cz>

Z dokumentu UM10360


Table 513. RTC Auxiliary control register (RTC_AUX - address 0x4002 405C)
bit description
Bit Symbol Description Reset
value
3:0 - Reserved, user software should not write ones to reserved bits. The
value read from a
reserved bit is not defined.
NA
4 RTC_OSCF RTC Oscillator Fail detect flag.
Read: this bit is set if the RTC oscillator stops, and when RTC power is
first turned on. An
interrupt will occur when this bit is set, the RTC_OSCFEN bit in RTC_AUXEN
is a 1, and the
RTC interrupt is enabled in the NVIC.
Write: writing a 1 to this bit clears the flag.
1
31:5 - Reserved, user software should not write ones to reserved bits. The
value read from a
reserved bit is not defined

______________________________________________________________
> Od: "Jan Waclawek" <konfera na efton.sk>
> Komu: "HW-news" <hw-list na list.hw.cz>
> Datum: 24.08.2024 12:20
> Předmět: Re: Indikacia zastavenia RTC, was: pamet "na chvili"
>
>> Já to pouµívám na procesoru stejné kategorie (cortex M3) od nxp, a tam je bit osc-fault.
>
>Ktory menovite? Zbezne som pozrel LPC17xx a tam som nic take nenasiel, ale
>mozno ste mysleli na niektory z biliona ex-Freescale mcu, v tych sa vobec
>neorientujem. Vcelku by ma zaujimalo, ako tento konkretny detail riesia
>rozni vyrobcovia.
>
_______________________________________________
HW-list mailing list  -  sponsored by www.HW.cz
Hw-list na list.hw.cz
http://list.hw.cz/mailman/listinfo/hw-list