507
/
838
Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
Figure 19-5 Control transfer
Isochronous transfer
Transmissions that require a fixed and precise data rate are defined as isochronous transfer. If an endpoint is defined
as a isochronous endpoint during enumeration, the USB host will allocate the required bandwidth for the endpoint in
OUT(1)
DATA1
SETUP(0)
DATA0
Tx = STALL
Rx = VALID
USB bus
Tx = NAK
Rx = NAK
Tx = STALL
Rx = VALID
OUT(0)
DATA0
Tx = VALID
Rx = VALID
IN(1)
DATA1
Tx = VALID
Rx = STALL
Tx = STALL
Rx = NAK
Tx =STALL
Rx = NAK
Tx = VALID
Rx = STALL
IN(0)
DATA0
Tx = NAK
Rx = STALL
Tx = VALID
Rx = VALID
STATUS_OUT = 1
Tx = NAK
Rx = VALID
OUT(1)
DATA1
Tx = NAK
Rx = NAK
OUT(1)
DATA1
Tx = NAK
Rx = VALID
STATUS_OUT = 0
IN(1)
DATA1
Tx = NAK
Rx = STALL
IN(1)
DATA1
Tx = NAK
Rx = NAK
Tx = VALID
Rx = NAK