EFM32WG Datasheet, PDF (326/834 Pages) List of Unclassifed Manufacturers – The EFM32WG Wonder Gecko is the ideal choice for demanding 8-, 16-, and 32-bit energy sensitive applications.

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Figure 15.35. HNP When the Core is a B-Device
C1
Read
USB_GOTGINT
Device mode
(Receive Set Feat ure
Com m and and OTG FSM
is in b_peripheral st at e)
1. Program
USB_GOTGCTL.DEVSETHNPEN = 1
2. Program
USB_GOTGCTL.HNPREQ = 1
No
Interrupt ?
No
Read
USB_GINTSTS
USB_GINTSTS.
ERLYSUSP = 1?
No
Yes No
Interrupt ?
No
Read
USB_GINTSTS
USB_GOTGINT.
HSTNEGSUCSTSCHNG = 1 ?
Yes
Clear USB_GOTGINT.
HSTNEGSUCSTSCHNG
Read
USB_GOTGCTL
USB_GOTGCTL.
HSTNEGSUCS = 1 ?
No
Yes
Read USB_GINTSTS. Check
t hat CURMOD = 1.
Rem ain as
Device
Host Init ializat ion St eps
(USB_HPRT.PRTPWR should
not be program m ed). For m ore
inform ation, see Host
Initialization section in this
chapter.
St art of Host
t r an sact ion s
End of Host
t r an sact ion s
Set USB_HPRT.PRTSUSP = 1.
Unm ask GINTSTS.OTGINT.
6.1. 1 Host Init ializat ion
(USB_HPRT.PRTPWR should
not be programmed)
USB_GINTSTS.
USBSUSP = 1?
Yes
Interrupt ? ^No
Yes
No
Read
USB_GINTSTS
USB_GINTSTS.
OTGINT = 1?
Yes
C1
Does B-
device want
to remain
host?
No
No
Yes
Pr o g r a m
USB_HPRT.PRTRES = 1 for
a predefined time.
The applicat ion
should ensure that
this process happens
within200 ms
Interrupt ?
No
Read
USB_GINTSTS
USB_GINTSTS.
DISCONNINT = 1 ?
Yes
Read USB_GINTSTS.CURMOD
and ensure it is 0.
Device Init ializat ion St e. ps
For m ore inform at ions,ee
Device Initialization
sect ion in t his chap. t er
Device Mode
Transact ions
Note
During HNP process where the B-device is going to assume the role of a host, the B-device
application needs to ensure that a USB reset process is programmed (in USB_HPRT
2013-05-08 - Wonder Gecko Family - d0233_Rev0.50
326
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