UM0842
Configuration
Doc ID 16542 Rev 4
17/50
5.11 Reset
button
A manual reset button (B3) is available on the board's top side. It resets the microprocessor
on the core board. It can be disconnected from the input reset signal of the core board by
soldering out resistor R65. In order to perform a hardware reset of the first Ethernet PHY U5
(ETH1), it is necessary to drive low pin PL_GPIO66 of the microprocessor. In order to
perform a hardware reset of the second Ethernet PHY U6 (ETH2), it is necessary to drive
low pin PL_GPIO76 of the microprocessor.
5.12 MicroSD
card
The MicroSD card connector connected to the SDIO interface of the EVALSPEAR320PLC is
available on the board. MicroSD card detection is managed by the standard SDIO signal
SDCD when the card is inserted. In order to power-up the MicroSD card properly, it is
necessary to detect the card insertion and then to enable the single channel power switch
U15 by means of PL_GPIO61 (active low).
Using the thermal and short-circuit protection of the power switch, it is possible to detect
overcurrent conditions (> 500 mA) on the MicroSD card connector by pin PL_GPIO57 which
is connected to the overcurrent pin of U15. By default the U15 power output is disabled by
the R83 pull-up resistor connected to the Enable pin of the power switch.
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