NXP Semiconductors MKL25Z128VLK4 - OTG Dual Role B Device Operation

Table 35-96. State descriptions for the dual role A device flow (continued)
State Action Response
A_WAIT_BCON After 200 ms without Attach or ID Interrupt. (This could wait forever
if desired.)
Go to A_WAIT_FALL
Turn off DRV_VBUS
A_VBUS_VLD Interrupt and B device attaches Go to A_HOST
Turn on Host mode
A_HOST Enumerate Device determine OTG Support.
If A_VBUS_VLD/ Interrupt or A device is done and doesn't think he
wants to do something soon or the B device disconnects
Go to A_WAIT_VFALL
Turn off Host mode
Turn off DRV_VBUS
If the A device is finished with session or if the A device wants to
allow the B device to take bus.
Go to A_SUSPEND
ID Interrupt or the B device disconnects Go to A_WAIT_BCON
A_SUSPEND If ID Interrupt, or if 150 ms B disconnect timeout (This timeout value
could be longer) or if A_VBUS_VLD\ Interrupt
Go to A_WAIT_VFALL
Turn off DRV_VBUS
If HNP enabled, and B disconnects in 150 ms then B device is
becoming the host.
Go to A_PERIPHERAL
Turn off Host mode
If A wants to start another session Go to A_HOST
A_PERIPHERAL If ID Interrupt or if A_VBUS_VLD interrupt Go to A_WAIT_VFALL
Turn off DRV_VBUS.
If 3 –200 ms of Bus Idle Go to A_WAIT_BCON
Turn on Host mode
A_WAIT_VFALL If ID Interrupt or (A_SESS_VLD/ & b_conn/) Go to A_IDLE
35.7.2 OTG dual role B device operation
A device is considered a B device if it connected to the bus with a USB Type B cable or a
USB Type Mini B cable.
A dual role B device operates as the following flow diagram and state description table
illustrates.
Chapter 35 Universal Serial Bus OTG Controller (USBOTG)
KL25 Sub-Family Reference Manual, Rev. 3, September 2012
Freescale Semiconductor, Inc. 649