Hardware layout and configuration
UM1902
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DocID027916 Rev 2
5.7
USB OTG FS1
STM32746G-EVAL evaluation board supports USB OTG full speed communication via a
USB Micro-AB connector (CN13) and USB power switch (U11) connected to VBUS. The
evaluation board can be powered by this USB connection at 5 V DC with 500 mA current
limitation.
A green led LD7 will be lit in one of these cases:
•
Power switch (U11) is ON and STM32746G-EVAL works as a USB host
•
VBUS is powered by another USB host when STM32746G-EVAL works as a USB
device
The red led LD8 will be lit when overcurrent occurs.
Note 1
STM32746G-EVAL evaluation board should be powered by external power supply when
using OTG function.
Note 2
JP8 must be removed when using USB OTG FS as mentioned in
5.8
USB OTG HS and USB OTG FS2
STM32746G-EVAL evaluation board supports USB OTG FS2:
•
High speed communication via a USB Micro-AB connector (CN8), USB High speed
PHY (U8) for high speed function.
•
Full speed communication via another USB Micro-AB connector (CN14)
The evaluation board can be powered by these USB connectors (CN8 or CN14) at 5 V DC
with 500 mA current limitation.
As several OTG FS2 signals are shared with OTG HS ULPI bus, some PCB reworks are
needed, when using OTG FS2 (CN14), as shown in
.
An USB power switch (U7) is also connected on VBUS and provides power to either CN8
(with SB12 and SB15 closed and SB13 and SB14 open), or CN14 (with SB13 and SB14
closed and SB12 and SB15 open).
Green led LD5 (for CN8) or LD9 (for CN14) will be lit when either power switch (U7) is ON
and STM32746G-EVAL works as a USB host, or VBUS is powered by another USB host
when STM32746G-EVAL works as a USB device.
The red led LD6 will be lit when over-current occurs.
Note:
STM32746G-EVAL evaluation board should be powered, by an external power supply when
using OTG function.
Table 7. USB OTG FS2 function configuration
Function
Mount
Remove
OTG HS-CN8 (Default)
R109,R115,SB12,SB15
R259,SB13,SB14,SB51
OTG FS2-CN14
R259,SB13,SB14,SB51
R109,R115,SB12,SB15
