Usb Function Controller Initialization Example - Freescale Semiconductor MPC850 User Manual

USB Function Controller Initialization Example

17. Write 0x2008_2028 to DPRAM+0x520 to set up the RBASE and TBASE fields of
the endpoint 1 parameter RAM.
18. Write 0x1818_0100 to DPRAM+0x524 to set up the RFCR, TFCR, and MRBLR
fields of the endpoint 1 parameter RAM.
19. Write 0x2008_2028 to DPRAM+0x528 to set up the RBPTR and TBPTR fields of
the endpoint 1 parameter RAM.
20. Clear the TSTATE field of the endpoint 1 parameter RAM.
21. Write 0x0000 to USEP0 for endpoint 0, control transfer, one packet only.
22. Write 0x1100 to USEP1 for endpoint 1, interrupt transfer, one packet only.
23. Write 0x2200 to USEP2 for endpoint 2, bulk transfer, one packet only.
24. Write 0x3300 to USEP3 for endpoint 3, isochronous transfer, one packet only.
25. Write 0x06 to USMOD for full-speed 12 Mbps signaling, local loopback
configuration (test and host modes set), and disable the USB.
26. Write 0x05 to the USAD for slave address 5.
27. Clear USCOM.
28. Set USMOD[EN] to enable the USB controller.
29. Write 0x80 to the USCOM to start filling the Tx FIFO with endpoint 0 data ready
for transmission.
30. Write 0x81 to the USCOM to start filling the Tx FIFO with endpoint 1 data ready
for transmission when an IN token is received.
The expected results are as follows:
• TxBD[Status and Control] of endpoint 0 should contain 0x3800.
• TxBD[Data Length] of endpoint 0 should contain 0x0003.
• TxBD[Status and Control] of endpoint 1 should contain 0x3C80.
• TxBD[Data Length] of endpoint 1 should contain 0x0003.
• RxBD[Status and Control] of endpoint 0 should contain 0x3C00.
• RxBD[Data Length] of endpoint 0 should contain 0x0005.
• The receive buffer of endpoint 0 should contain 0xABCD_122B, 0x42xx_xxxx.
32.12 USB Function Controller Initialization Example
The following is an example initialization sequence for the USB controller operating in
function mode. It can be used to set up four function endpoints (0–3) to fill transmit FIFOs
so that data is ready for transmission when an IN token is received from the USB. The token
can be generated using a USB traffic generator.
MPC850 Family User's Manual