Atmel Evaluation Kit AT91SAM9M10-G45-EK AT91SAM9M10-G45-EK Data Sheet

 805

SAM9M10 [DATASHEET]

6355F–ATARM–12-Mar-13

STALL is returned by a function in response to an IN token or after the data phase of an OUT or in response to a
PING transaction. STALL indicates that a function is unable to transmit or receive data, or that a control pipe
request is not supported. 

• OUT

To stall an endpoint, set the FRCESTALL bit in UDPHS_EPTSETSTAx register and after the STALL_SNT flag has
been set, set the TOGGLE_SEG bit in the UDPHS_EPTCLRSTAx register.

• IN

Set the FRCESTALL bit in UDPHS_EPTSETSTAx register.

Stall Handshake Data OUT Transfer

Stall Handshake Data IN Transfer 

Token OUT  

Stall PID

 

Data OUT

USB Bus
Packets

Cleared by Firmware

Set by Firmware

FRCESTALL 

STALL_SNT

Set by Hardware

Interrupt Pending

Cleared by Firmware

Token IN 

Stall PID

USB Bus
Packets

Cleared by Firmware

Set by Firmware

FRCESTALL 

STALL_SNT

Set by Hardware

Cleared by Firmware

Interrupt Pending