STM32F779IGH7 datasheet(29/255 Pages) STMICROELECTRONICS

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STM32F777xx STM32F778Ax STM32F779xx

Functional overview

Figure 5. VDDUSB connected to external power supply

The DSI (Display Serial Interface) sub-system uses several power supply pins which are

independent from the other supply pins:

•

VDDDSI is an independent DSI power supply dedicated for DSI Regulator and

MIPI D-PHY. This supply must be connected to global VDD.

•

The VCAPDSI pin is the output of DSI Regulator (1.2V) which must be connected

externally to VDD12DSI.

•

The VDD12DSI pin is used to supply the MIPI D-PHY, and to supply the clock and data

lanes pins. An external capacitor of 2.2 uF must be connected on the VDD12DSI pin.

•

The VSSDSI pin is an isolated supply ground used for DSI sub-system.

•

If the DSI functionality is not used at all, then:

–

The VDDDSI pin must be connected to global VDD.

–

The VCAPDSI pin must be connected externally to VDD12DSI but the external

capacitor is no more needed.

–

The VSSDSI pin must be grounded.

2.18

Power supply supervisor

2.18.1

Internal reset ON

On packages embedding the PDR_ON pin, the power supply supervisor is enabled by

holding PDR_ON high. On the other packages, the power supply supervisor is always

enabled.

The device has an integrated power-on reset (POR)/ power-down reset (PDR) circuitry

coupled with a Brownout reset (BOR) circuitry. At power-on, POR/PDR is always active and

ensures proper operation starting from 1.8 V. After the 1.8 V POR threshold level is

reached, the option byte loading process starts, either to confirm or modify default BOR

thresholds, or to disable BOR permanently. Three BOR thresholds are available through

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