Rainbow Electronics AT89C5122 - Manual (Page 98)

98
AT8xC5122/23
4202E–SCR–06/06
Figure 52. Minimum Intervention from the USB Device Firmware
OUT Transactions:
HOST
UFI
C51 OUT DATA0 (n Bytes)
ACK
Endpoint FIFO read (n bytes)
OUT DATA1
NACK
OUT DATA1
ACK
IN Transactions:
HOST
UFI
C51 IN ACK
Endpoint FIFO write
IN
DATA1 NACK
interrupt C51
IN
DATA1
interrupt C51
Endpoint FIFO write