Datasheet

544
SAM9X25 [DATASHEET]
11054E–ATARM–10-Mar-2014
Figure 32-11.Data IN Followed By Status OUT Transfer at the End of a Control Transfer
Note: A NAK handshake is always generated at the first status stage token.
Figure 32-12.Data OUT Followed by Status IN Transfer
Note: Before proceeding to the status stage, the software should determine that there is no risk of extra data from the host
(data stage). If not certain (non-predictable data stage length), then the software should wait for a NAK-IN interrupt
before proceeding to the status stage. This precaution should be taken to avoid collision in the FIFO.
Token OUT
Data IN
Token IN
ACK
ACK
Data OUT (ZLP)
RXRDY
(UDPHS_EPTSTAx)
TX_COMPLT
(UDPHS_EPTSTAx)
Set by Hardware
Set by Hardware
USB Bus
Packets
Cleared by Firmware
Cleared by Firmware
Device Sends a
Status OUT to Host
Device Sends the Last
Data Payload to Host
Interrupt
Pending
Token OUT
ACK
Data OUT (ZLP)
Token INACKData OUTToken OUT ACKData IN
USB Bus
Packets
RXRDY
(UDPHS_EPTSTAx)
Cleared by Firmware
Set by Hardware
Clear by Hardware
TXRDY
(UDPHS_EPTSTAx)
Set by Firmware
Host Sends the Last
Data Payload to the Device
Device Sends a Status IN
to the Host
Interrupt Pending