EFM32WG Datasheet, PDF (256/834 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 15.10. Transmit FIFO Write Task in Slave Mode
Read USB_GNPTXSTS /
USB_HPTXFSIZ regist ers
for available FIFO and
Queue spaces
St art
Wait for
USB_GAHBCFG . NPTXFEMPLVL
1 MPS
or
No
or LPS FIFO space
Yes
USB_GAHBCFG . PTXFEMPLVL
available?
interrupt
Yes
Write1 packet
data to
Transm it FIFO
MPS : Max Packet Size
LPS : Last Packet Size
More packets
to send?
No
Done
15.4.3.6.2 Reading the Receive FIFO in Slave Mode
Figure 15.11 (p. 256) shows the flow diagram for reading the receive FIFO in Slave mode. The
application must ignore all packet statuses other than IN Data Packet (0b0010).
Figure 15.11. Receive FIFO Read Task in Slave Mode
St art
No
Unm ask RXFLVL
interrupt
Read t he received
packet from the
Receive FIFO
Yes
RXFLVL
In t er r u p t ?
Yes
Mask RXFLVL
interrupt
Read
USB_GRXSTSP
PKTSTS =
0 b 0 0 1 0?
Yes
BCNT > 0 ?
Unm ask RXFLVL
interrupt
No
No
15.4.3.6.3 Control Transactions in Slave Mode
Setup, Data, and Status stages of a control transfer must be performed as three separate transfers.
Setup- Data- or Status-stage OUT transactions are performed similarly to the bulk OUT transactions
explained in Bulk and Control OUT/SETUP Transactions in Slave Mode(p. 257) . Data- or Status-
stage IN transactions are performed similarly to the bulk IN transactions explained in Bulk and Control
IN Transactions in Slave Mode (p. 259) For all three stages, the application is expected to set the
USB_HC1_CHAR.EPTYPE field to Control. During the Setup stage, the application is expected to set
the USB_HC1_TSIZ.PID field to SETUP.
2013-05-08 - Wonder Gecko Family - d0233_Rev0.50
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