www.ti.com

USB Controller Host and Peripheral Modes Operation

3.2.1.4IN Status Phase (following SETUP Phase or OUT Data Phase)

For the IN Status Phase of a Control Transaction (Figure 12), the software driving the USB Host device needs to:

1.Set the STATUSPKT and REQPKT bits of HOST_CSR0 (bit 6 and bit 5, respectively).

2.Wait while the controller sends an IN token and receives a response from the USB peripheral device.

Figure 12. Completion of SETUP or OUT Data Phase Flow Chart

Completion of either SETUP phase or OUT data phase

 

 

No

NAK limit

 

 

reached

 

 

 

 

 

 

 

 

 

 

?

 

 

 

 

 

 

 

Error count

 

 

 

 

 

 

cleared

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

NAK Timeout set

Endpoint halted

Interrupt generated

ReqPkt

and StatusPkt

both set

?

Yes

IN token sent

STALL received

?

No

Yes NAK received

?

No

Data1 received

?

No

Error count incremented

No Error count=3

?

No

 

 

 

 

RxStall set

 

Command could

Yes

 

not be completed

ReqPkt cleared

 

 

Error Count cleared

 

 

Interrupt generated

 

Yes

ACK sent

ReqPkt cleared

RxPktRdy

Error Count cleared

 

 

set

Interrupt generated

 

 

Transaction

 

 

 

complete

 

 

 

Implies problem

 

Error bit set

at peripheral end

Yes

of connection.

ReqPkt cleared

 

 

Error Count cleared

 

 

Interrupt generated

 

 

 

 

Transaction deemed

 

 

 

complete

SPRUGH3–November 2008

Universal Serial Bus (USB) Controller

49

Submit Documentation Feedback

Page 49
Image 49
Texas Instruments TMS320DM357 manual Status Phase following Setup Phase or OUT Data Phase