COMMELL MPX-2515 - Manual (Page 4)

Commell MPX-2515 User’s Guide Rev 0100
Taiwan Commate Computer Inc. 4
Figure 1 CCANP Transactions and Operation Sequences
A response packet is corresponding to a request packet. And hence USB host
applications usually first issue a CCANP Request Packet to the MPX-2515 card via a
BULK OUT (at endpoint 2) transfer and then issue a CCP Response Packet to the
MPX-2515 card via a BULK IN (at endpoint 1) transfer. The application should
always check the Status Code filed in the response packet in order to determine the
final status of the corresponding request carried out in the connected CAN bus.
1.2 Interrupt In Packet
The MPX-2515 card provides status packet that the USB host can read out in order
to realize the status of the MPX-2515 controller as well as the connecting CAN bus
activities.
USB
Host
Application MPX-2515
Firmware
Request Packet
Request Packet
Response Packet
Response Packet
EP2
EP1
EP2
EP1
Interrupt In Packet EP3
Read FMB Packet EP4