UM0842 datasheet(17/50 Pages) STMICROELECTRONICS

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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.

UM0842 Datasheet(PDF) 17 Page - STMicroelectronics