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Zdravim,<br>
jeste toto je z datahseetu:<br>
<br>
<br>
PC13, PC14, PC15 and PI8 are supplied through the power switch
<div data-canvas-width="331.00773999999996" style="left: 521.8px;
top: 821.463px; font-size: 13.3px; font-family: sans-serif;
transform: scaleX(1.0061);">. Since the switch only sinks a
limited amount of current </div>
<div data-canvas-width="442.8407900000001" style="left: 129.2px;
top: 834.863px; font-size: 13.3px; font-family: sans-serif;
transform: scaleX(1.01569);">(3 mA), the use of GPIOs PC13 to PC15
and PI8 in output mode is limited: </div>
<div data-canvas-width="408.67309000000006" style="left: 129.2px;
top: 848.163px; font-size: 13.3px; font-family: sans-serif;
transform: scaleX(1.02032);">- The speed should not exceed 2 MHz
with a maximum load of 30 pF.</div>
<div data-canvas-width="431.0157600000001" style="left: 129.2px;
top: 861.563px; font-size: 13.3px; font-family: sans-serif;
transform: scaleX(1.02136);">- These I/Os must not be used as a
current source (e.g. to drive an LED).</div>
<br>
<br>
Power switch, ktery je nakreslen je u RTC a spinani napeti na RTC
(presne nereknu datasheeet, musel bych prohledat). Na pouzdru
lqfpf64 je velmi citlivy ten odber na pinech vedle RTC oscilatoru
(ze zkusenosti). Dedukuji, ze tyhle piny a RTC bezi na stejne vetvi
napajeni, mozna to je i nekde uvedeno. Je to kazdopadne citlive na
chod RTC krystalu 32kHz.<br>
<br>
Jirka<br>
<br>
Dne 17. 6. 2015 v 14:35 Jiří Nesvačil napsal(a):<br>
<blockquote cite="mid:55816980.1080700@posys.cz" type="cite">Posledni
piny vedle RTC oscilatoru jsou napajeny ze stabilizatoru jako RTC.
V datahseetu je myslim nakreslen mosfet na spinani napeti pro RTC,
mozna to je jen tranzistor, nicmene to nezvlada velke zatizeni
tech pinu vedle RTC oscilatoru.
<br>
<br>
Pokud se to nedodrzi, tak spolu s nedodrzenim kapacity krystalu
to doopravdy je nadhodny kus od kusu, kdy ten RTC nenabehne. Spíse
to nabehne, ale nektere kusy ne, o to to je horsi.
<br>
<br>
Nicmene toto plati pro kazdou radu STM32 malinko jinak, mozna to
neni ani dokumentovano u nektere rady. Nicmene v te aplikacni
poznamce na doporuceni krystalu lze dedukovat... .
<br>
<br>
Jirka
<br>
<br>
<br>
ad 2/ STM32 ma stabilizator u hodin vyuzit i pro posledni piny
na CPU.
<br>
<blockquote type="cite">
<blockquote type="cite">Aky stabilizator? Poprosim odkaz na
RM/DS ci iny material.
<br>
<br>
Co su to "posledne piny na CPU"?
<br>
<br>
</blockquote>
</blockquote>
<br>
<br>
<br>
<br>
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</blockquote>
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