RM0390 Rev 4 1239/1328
RM0390 USB on-the-go full-speed/high-speed (OTG_FS/OTG_HS)
1264
Endpoint initialization on SetConfiguration/SetInterface command
This section describes what the application must do when it receives a SetConfiguration or
SetInterface command in a SETUP packet.
1. When a SetConfiguration command is received, the application must program the
endpoint registers to configure them with the characteristics of the valid endpoints in
the new configuration.
2. When a SetInterface command is received, the application must program the endpoint
registers of the endpoints affected by this command.
3. Some endpoints that were active in the prior configuration or alternate setting are not
valid in the new configuration or alternate setting. These invalid endpoints must be
deactivated.
4. Unmask the interrupt for each active endpoint and mask the interrupts for all inactive
endpoints in the OTG_DAINTMSK register.
5. Set up the data FIFO RAM for each FIFO.
6. After all required endpoints are configured; the application must program the core to
send a status IN packet.
At this point, the device core is configured to receive and transmit any type of data packet.
Endpoint activation
This section describes the steps required to activate a device endpoint or to configure an
existing device endpoint to a new type.
1. Program the characteristics of the required endpoint into the following fields of the
OTG_DIEPCTLx register (for IN or bidirectional endpoints) or the OTG_DOEPCTLx
register (for OUT or bidirectional endpoints).
– Maximum packet size
– USB active endpoint = 1
– Endpoint start data toggle (for interrupt and bulk endpoints)
– Endpoint type
– Tx FIFO number
2. Once the endpoint is activated, the core starts decoding the tokens addressed to that
endpoint and sends out a valid handshake for each valid token received for the
endpoint.
Endpoint deactivation
This section describes the steps required to deactivate an existing endpoint.
1. In the endpoint to be deactivated, clear the USB active endpoint bit in the
OTG_DIEPCTLx register (for IN or bidirectional endpoints) or the OTG_DOEPCTLx
register (for OUT or bidirectional endpoints).
2. Once the endpoint is deactivated, the core ignores tokens addressed to that endpoint,
which results in a timeout on the USB.
Note: The application must meet the following conditions to set up the device core to handle
traffic:
NPTXFEM and RXFLVLM in the OTG_GINTMSK register must be cleared.
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