EFM32WG Datasheet, PDF (308/834 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 15.26. USBTRDTIM Max Timing Case ERROR wrong image
H ost
USB
IN
NAK
D e v ice
Applicat ion
INTKNTXFEMP
INTR
idle( wait_int r)
XferSize = 1025 byt es
Pkt Cnt = 3
EPEna = 1
xac_t 1 of2
xac_t 2 of2
IN
512 bytes
ACK
IN
STALL
IN
STALL
new xact
IN
NAK
IN
512 bytes
xact_ 1 dat a rdy
set up_ np_in_ pkt
NPTXFEMP INT
set up_ np_in_ pkt
xact_ 2 dat a rdy
EPDisabled int r
set_ st all
ep_ disable;
1
do_in_ xfer
2
flush_ nper_ t x_ fifo;
3
Clr Global IN NP Nak
4
wait_for_ host/
app to clr stall
5
clr_ st all
INTIKNNTTRXFEMP
do_ in_ xfer
A CK
15.4.4.2.3.10 Handling Babble Conditions
If receives a packet that is larger than the maximum packet size for that endpoint, the core stops writing
data to the Rx buffer and waits for the end of packet (EOP). When the core detects the EOP, it flushes
the packet in the Rx buffer and does not send any response to the host.
If the core continues to receive data at the EOF2 (the end of frame 2, which is very close to SOF), the
core generates an early_suspend interrupt (USB_GINTSTS.ERLYSUSP). On receiving this interrupt,
the application must check the erratic_error status bit (USB_DSTS.ERRTICERR). If this bit is set, the
application must take it as a long babble and perform a soft reset.
15.4.4.2.3.11 Generic Non-Periodic (Bulk and Control) IN Data Transfers in DMA and Slave Mode
To initialize the core after power-on reset, the application must follow the sequence in Overview:
Programming the Core (p. 246) . Before it can communicate with the host, it must initialize an endpoint
as described in Endpoint Initialization (p. 281) . For packet writes in Slave mode, see: Packet Write
in Slave Mode (p. 303) .
Application Requirements
1. Before setting up an IN transfer, the application must ensure that all data to be transmitted as part of
the IN transfer is part of a single buffer, and must program the size of that buffer and its start address
(in DMA mode) to the endpoint-specific registers.
2. For IN transfers, the Transfer Size field in the Endpoint Transfer Size register denotes a payload
that constitutes multiple maximum-packet-size packets and a single short packet. This short packet
is transmitted at the end of the transfer.
2013-05-08 - Wonder Gecko Family - d0233_Rev0.50
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