CC2510_15 Datasheet, PDF (169/245 Pages) Texas Instruments – Low-Power SoC (System-on-Chip) with MCU, Memory,2.4 GHz RF Transceiver, and USB Controller

CC2511F8 - Not Recommended for New Designs
Endpoint 0 is controlled through the USBCS0
register by setting the USBINDEX register to 0.
The USBCNT0 register contains the number of
bytes received.
12.16.5 Endpoint 0 Interrupts
The following events may generate an EP0
interrupt request:
• A data packet has been received
(USBCS0.OUTPKT_RDY=1)
• A data packet that was loaded into the
EP0 FIFO has been sent to the USB
host (USBCS0.INPKT_RDY should be
set to 1 when a new packet is ready to
be transferred. This bit will be cleared by
HW when the data packet has been
sent)
• An IN transaction has been completed
(the interrupt is generated during the
Status stage of the transaction)
• A STALL has been sent
(USBCS0.SENT_STALL=1)
• A control transfer ends due to a
premature end of control transfer
(USBCS0.SETUP_END=1)
Any of these events will cause the
USBIIF.EP0IF to be asserted regardless of
the status of the EP0 interrupt mask bit
USBIIE.EP0IE. If the EP0 interrupt mask bit
is set to 1, the CPU interrupt flag
IRCON2.USBIF will also be asserted. An
interrupt request is only generated if
IEN2.USBIE and USBIIE.EP0IE are both
set to 1.
12.16.5.1 Error Conditions
When a protocol error occurs, the USB
controller sends a STALL handshake. The
USBCS0.SENT_STALL bit is asserted and an
interrupt request is generated if the endpoint 0
interrupt is properly enabled. A protocol error
can be any of the following:
• An OUT token is received after
USBCS0.DATA_END has been set to
complete the OUT Data stage (the host
tries to send more data than expected)
• An IN token is received after
USBCS0.DATA_END has been set to
complete the IN Data stage (the host
tries to receive more data than
expected)
CC2510Fx / CC2511Fx
• The USB host tries to send a packet that
exceeds the maximum packet size
during the OUT Data stage
• The size of the DATA1 packet received
during the Status stage is not 0
The firmware can also terminate the current
transaction
by
setting
the
USBCS0.SEND_STALL bit to 1. The USB
controller will then send a STALL handshake in
response to the next requests from the USB
host.
If an EP0 interrupt is caused by the assertion
of the USBCS0.SENT_STALL bit, this bit
should be de-asserted and firmware should
consider the transfer as aborted (free memory
buffers etc.).
If EP0 receives an unexpected token during
the Data stage, the USBCS0.SETUP_END bit
will be asserted and an EP0 interrupt will be
generated (if enabled properly). EP0 will then
switch to the IDLE state. Firmware should then
set the USBCS0.CLR_SETUP_END bit to 1 and
abort the current transfer. If
USBCS0.OUTPKT_RDY is asserted, this
indicates that another Setup Packet has been
received that firmware should process.
12.16.5.2 SETUP Transactions (IDLE State)
The control transfer consists of 2 - 3 stages of
transactions (Setup - Data - Status or Setup -
Status). The first transaction is a Setup
transaction. A successful Setup transaction
comprises three sequential packets (a token
packet, a data packet, and a handshake
packet), where the data field (payload) of the
data packet is exactly 8 bytes long and are
referred to as the Setup Packet. In the Setup
stage of a control transfer, EP0 will be in the
IDLE state. The USB controller will reject the
data packet if the Setup Packet is not 8 bytes.
Also, the USB controller will examine the
contents of the Setup Packet to determine
whether or not there is a Data stage in the
control transfer. If there is a Data stage, EP0
will switch state to TX (IN transaction) or RX
(OUT
transaction)
when
the
USBCS0.CLR_OUTPKT_RDY bit is set to 1 (if
USBCS0.DATA_END=0).
When a packet is received, the
USBCS0.OUTPKT_RDY bit will be asserted and
an interrupt request is generated (EP0
interrupt) if the interrupt has been enabled.
Firmware should perform the following when a
Setup Packet has been received:
SWRS055G
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