EFM32WG Datasheet, PDF (319/834 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 15.31. Periodic IN Core Internal Flow for Periodic Transfer Interrupt Feature
START
If (USB_DIEPx_CTL.CNAK = 0b1) & &
(USB_DIEPxCTL.EPENA = 0b1) & &
(USB_DCTL.IGNRFRMNUM = 0b1)
NOTE
1 . Core w ill fe t ch da t a only from DW ORD Aligne d a ddre sse s
2 . Cor e w ill n ot t a g Pe r iod ic IN Pa ck e t s t(omaicsr)op ef rcaifmice n u m b e r
3 . In ca se cor e is n ot a b le t o se n d ou t d a t a f o( mr tichre)o cf ruarmr een t h e
d a t a w ill n ot b e f lu sh e d a n d w ill b e se n t o(umt iicnr)otfhr aemne xt
4. The DATA PID of t he packet w hich w as not sent in t he previous
( m icr)o f r a m e w ill r e m a in t h e sa m e
5 . Sh or t Pa ck e t s a r e n ot a llow e d in b e t w e.e nOtnrlayntshfe rlsa st p a ck e t
can have a Short Packet
IN Tok e n Fr om H ost YES
· ISOC IN Transm it Zero Lengt h (PZaLcPk)et
Ch e ck D a t a Ava ila b le NO _{· Int errupt IN Xm it NAK Packet}
WAIT
YES
· Transm it Dat a Packet
· Mult Cn=t Mult Cn-t1
· Pkt Cnt= Pkt Cn-t 1
· XferSize= XferSiz-e MaxPkt Size
· Mult Cn=t Mult Cnt
· Pkt Cnt= Pkt Cnt
· XferSize= XferSize
// M u lt Cn, t Pk t Cn t a n d X f e r Size va lu e s w ill
not change
If
M u lt Cn=t0
If Pk t Cn=t=0 & &
X f e r Siz=e =0
Mult Cn=t USB_DIEPx_TSIZ.MC
YES
NO
USB_DIEPx_INT.XFERCOMPL = 1
return
15.4.5 OTG Revision 1.3 Programming Model
This section describes the OTG programming model when the core is configured to support OTG
Revision 1.3 of the specification.
The core is an OTG device supporting HNP and SRP. When the core is connected to an “A” plug, it is
referred to as an A-device. When the core is connected to a “B” plug it is referred to as a B-device. In
Host mode, the core turns off Vbus to conserve power. SRP is a method by which the B-device signals
the A-device to turn on Vbus power. A device must perform both data-line pulsing and Vbus pulsing,
but a host can detect either data-line pulsing or Vbus pulsing for SRP. HNP is a method by which the
B-device negotiates and switches to host role. In Negotiated mode after HNP, the B-device suspends
the bus and reverts to the device role.
15.4.5.1 A-Device Session Request Protocol
The application must set the SRP-Capable bit in the Core USB Configuration register. This enables the
core to detect SRP as an A-device.
1. To save power, the application suspends and turns off port power when the bus is idle by writing the
Port Suspend and Port Power bits in the Host Port Control and Status register.
2. PHY indicates port power off by detecting that VBUS voltage level is no longer valid.
3. The device must detect SE0 for at least 2 ms to start SRP when Vbus power is off.
4. To initiate SRP, the device turns on its data line pull-up resistor for 5 to 10 ms. The core detects
data-line pulsing.
5. The device drives Vbus above the A-device session valid (2.0 V minimum) for Vbus pulsing.
The core interrupts the application on detecting SRP. The Session Request Detected bit is set in
Global Interrupt Status register (USB_GINTSTS.SESSREQINT).
2013-05-08 - Wonder Gecko Family - d0233_Rev0.50
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