phyCORE-OMAP44xx
Part II: PCM-959/phyCORE-OMAP44xx Carrier Board
L-760e_1 © PHYTEC Messtechnik GmbH 2012
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2.1.3.18 System Reset Button (S7)
Figure 44:
System Reset Button S7
The phyCORE Carrier Board is equipped with a system reset button at S7, a reset device (U23) and a LI-cell
(BAT1). Pressing the button will not only reset the phyCORE mounted on the phyCORE-OMAP44xx Carrier Board,
but also the peripheral devices, such as the USB Hub, etc.
S7 Issues a
system reset
signal. Pressing this button will toggle the X_nRESET_PWRON signal LOW, causing a
reset of the phyCORE-OMAP44xx and the peripheral devices on the carrier board.
"If the Lithium-Ion Battery (BAT1) is assembled and VCC_3V3 falls below 2.9 V, then the reset device (U23)
connects the Lithium-Ion Battery to the backup battery input (VBAT) of the phyCORE-OMAP44xx. This way the
RTC and some critical registers of the PMIC on the SOM are supplied by the Lithium-Ion Battery in case of a power
loss."
"If the Lithium-Ion Battery (BAT1) is not assembled and VCC_3V3 falls below 2.9 V, then the reset device (U23)
triggers a system reset by pulling X_nRESET_PWRON low."
