NXP Semiconductors KL25 Series - Freescale Semiconductor, Inc

complete. When the BDT is written, a token done (ISTAT[TOKDNE]) interrupt is
asserted. This completes the setup phase of the setup transaction. Se 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 (that is, 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 – BC to 64 (the byte count of the
data buffer in this case), 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 (ISTAT[DNE]) interrupt is asserted. For control transfers with a single
packet data phase this completes the data phase of the setup transaction. See 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 – BC to 0 (the byte count of the
data buffer in this case), OWN bit to 1, Data toggle to Data1.
• 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 from the device and a Token Done (ISTAT[TOKDNE])
interrupt is asserted. This completes the data phase of the setup transaction. See 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:
Host Mode Operation Examples
KL25 Sub-Family Reference Manual, Rev. 3, September 2012
646 Freescale Semiconductor, Inc.