Table 43-8. State descriptions for the dual role A device flow (continued)
State Action Response
Turn on Host mode
A_HOST Enumerate Device determine OTG Support.
If A_VBUS_VLD/ Interrupt or A device is done and does not think it
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
43.7.2 OTG dual role B device operation
A device is considered a B device if it is connected to the bus with a USB Type Standard-
B, Mini-B, or Micro-B plug inserted into the local USB receptacle. The Type Mini-B
plug and receptacle are now only allowed for dedicated peripheral devices, not dual-
role/OTG devices.
A dual role B device operates as the following flow diagram and state description table
illustrates.
Chapter 43 Universal Serial Bus Full Speed OTG Controller (USBFSOTG)
K22F Sub-Family Reference Manual, Rev. 4, 08/2016
NXP Semiconductors 1115
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