992
11100B–ATARM–31-Jul-12
SAM4S Series [Preliminary]
3.
The microcontroller is notified that the device has sent the stall by polling the
STALLSENT to be set. An endpoint interrupt is pending while STALLSENT is set. The
microcontroller must clear STALLSENT to clear the interrupt.
When a setup transaction is received after a stall handshake, STALLSENT must be cleared in
order to prevent interrupts due to STALLSENT being set.
Figure 38-13. Stall Handshake (Data IN Transfer)
Figure 38-14. Stall Handshake (Data OUT Transfer)
Data IN
Stall PID
PID
USB Bus
Packets
Cleared by Firmware
Set by Firmware
FORCESTALL
STALLSENT
Set by
USB Device
Cleared by Firmware
Interrupt Pending
Data OUT PID
Stall PID
Data OUT
USB Bus
Packets
Cleared by Firmware
Set by Firmware
FORCESTALL
STALLSENT
Set by USB Device
Interrupt Pending
Summary of Contents for SAM4S Series
Page 44: ...44 11100B ATARM 31 Jul 12 SAM4S Series Preliminary ...
Page 412: ...412 11100B ATARM 31 Jul 12 SAM4S Series Preliminary ...
Page 1105: ...1105 11100B ATARM 31 Jul 12 SAM4S Series Preliminary ...
Page 1143: ...1143 11100B ATARM 31 Jul 12 SAM4S Series Preliminary Figure 43 4 64 lead LQFP Package Drawing ...
Page 1145: ...1145 11100B ATARM 31 Jul 12 SAM4S Series Preliminary Figure 43 5 64 lead QFN Package Drawing ...