Samsung S3C6400X User Manual page 868

S3C6400X RISC MICROPROCESSOR
Stall
Snp
EPType [19:18]
NAKsts
Periodic endpoints must map this to the
corresponding Periodic TxFIFO number.
· 4'h0 : Non-Periodic TxFIFO
· Others : Specified Periodic TxFIFO number
Note: An interrupt IN endpoint could be configured
as a non-periodic endpoint for applications like mass
storage.
[21] R_W STALL Handshake
Applies to non-control, non-isochronous IN and OUT
endpoints only. The application sets this bit to stall
all tokens from the USB host to this endpoint. If a
NAK bit, Global Non-Periodic In NAK, or Global OUT
NAK is set along with this bit, the STALL bit takes
priority. Only the application can clear this bit, never
the core.
Applies to control endpoints only
R_WS_
The application can only set this bit, and the core
SC
clears it, when a SETUP token is received for this
endpoint. If a NAK bit, Global Non-Periodic IN NAK,
or Global OUT NAK is set along with this bit, the
STALL bit takes priority. Irrespective of this bit's
setting, the core always responds to SETUP data
packets with an ACK handshake.
[20] R_W Snoop Mode
Applies to OUT endpoints only.
This bit configures the endpoint to Snoop mode. In
Snoop mode, the core does not check the
correctness of OUT packets before transferring them
to application memory.
RO Endpoint Type
Applies to IN and OUT endpoints.
This is the transfer type supported by this logical
endpoint.
· 2'b00 : Control
· 2'b01 : Isochronous
· 2'b10 : Bulk
· 2'b11 : Interrupt
[17] RO NAK Status
Applies to IN and OUT endpoints.
Indicates the following:
· 1'b0 : The core is transmitting non-NAK
handshakes based on the FIFO status
· 1'b1 : The core is transmitting NAK handshakes on
this endpoint
When either the application or the core sets this bit:
· The core stops receiving any data on an OUT
endpoint, even if there is space in the RxFIFO to
accommodate the incoming packet.
For non-isochronous IN endpoints : The core stops
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
Specifications and information herein are subject to change without notice.
USB2.0 HS OTG
1'b0
1'b0
2'h0
1'b0
·
26-61