Figure 2-5. Back Channel Transaction Sequence
WirelessUSB™ Protocol 2.2
CRC Seed = A,A
CRC Seed = !A,A
CRC Seed = A,A
CRC Seed = !A,A
CRC Seed = A,A
CRC Seed = !A,A
CRC Seed = !A,A
Device 1
D e l a y
R
X
D e l a y
R
X
D
e
l
a y
R
X
D e l a y
R
X 
BCD=1
Auto ACK
Data
Auto ACK
BCD=1
Auto ACK
Data
Auto ACK
BCD=1
Auto ACK
Data BCD=1
Auto ACK
Data
Auto ACK
Bridge
CRC Seed = A,A
CRC Seed = !A,A
CRC Seed = A,A
CRC Seed = !A,A
CRC Seed = A,A
CRC Seed = !A,A
CRC Seed = !A,A
Device 2
Device 1 checks for back channel data
| Device 2 transmits |
| when device 1 is |
| looking for back |
| channel data |
CRC Seed = A,A | Device 1 and |
| bridge do not |
| respond to device |
| 2 due to seed |
| missmatch |
Dongle indicates that it has more data to send
CY4672 Reference Design Guide, Document # | 21 |
[+] Feedback
