Information

complete. When the BDT is written a token done (INT_STAT[TOK_DNE]) interrupt
is asserted. This completes the setup phase of the setup transaction. Refer to the
Universal Serial Bus Revision 2.0 specification, "Chapter 9 USB Device Framework"
(http://www.usb.org/developers/docs).
7. To initiate the data phase of the setup transaction (for example, get the data for the
GET DEVICE descriptor command) set up a buffer in memory for the data to be
transferred.
8. Initialize the current (even or odd) TX EP0 BDT to transfer the data.
• Set the BDT command word to 0x004000C0 –Byte count to the length of the
data buffer in this case 64, own bit to 1, Data toggle to Data1.
• Set the BDT buffer address field to the start address of the data buffer
9. Write the token register with a IN or OUT token to Endpoint 0 the target device
default control pipe, an IN token for a GET DEVICE DESCRIPTOR command
(TOKEN=0x90). This initiates an IN token on the bus followed by a data packet
from the device to the host. When the data packet completes the BDT is written and a
token done (INT_STAT[TOK_DNE]) interrupt is asserted. For control transfers with
a single packet data phase this completes the data phase of the setup transaction.
Refer to the Universal Serial Bus Revision 2.0 specification, "Chapter 9 USB Device
Framework" (http://www.usb.org/developers/docs).
10. To initiate the Status phase of the setup transaction set up a buffer in memory to
receive or send the zero length status phase data packet.
11. Initialize the current (even or odd) TX EP0 BDT to transfer the status data.
• Set the BDT command word to 0x00000080 –Byte count to the length of the
data buffer in this case 0, own bit to 1, Data toggle to Data0.
• Set the BDT buffer address field to the start address of the data buffer
12. Write the token register with a IN or OUT token to Endpoint 0 the target device
default control pipe, an OUT token for a GET DEVICE DESCRIPTOR command
(TOKEN=0x10). This initiates an OUT token on the bus followed by a zero length
data packet from the host to the device. When the data packet completes the BDT is
written with the handshake form the device and a token done
(INT_STAT[TOK_DNE]) interrupt is asserted. This completes the data phase of the
setup transaction. Refer to the Universal Serial Bus Revision 2.0 specification,
"Chapter 9 USB Device Framework" (http://www.usb.org/developers/docs).
To send a Full speed bulk data transfer to a target device:
Chapter 40 Universal Serial Bus OTG Controller (USBOTG)
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
Freescale Semiconductor, Inc. 919