Table 43-8. State descriptions for the dual role A device flow (continued)State Action ResponseTurn on Host modeA_HOST Enumerate Device determine OTG Support.If A_VBUS_VLD/ Interrupt or A device is done and does not think itwants to do something soon or the B device disconnectsGo to A_WAIT_VFALLTurn off Host modeTurn off DRV_VBUSIf the A device is finished with session or if the A device wants toallow the B device to take bus.Go to A_SUSPENDID Interrupt or the B device disconnects Go to A_WAIT_BCONA_SUSPEND If ID Interrupt, or if 150 ms B disconnect timeout (This timeout valuecould be longer) or if A_VBUS_VLD\ InterruptGo to A_WAIT_VFALLTurn off DRV_VBUSIf HNP enabled, and B disconnects in 150 ms then B device isbecoming the host.Go to A_PERIPHERALTurn off Host modeIf A wants to start another session Go to A_HOSTA_PERIPHERAL If ID Interrupt or if A_VBUS_VLD interrupt Go to A_WAIT_VFALLTurn off DRV_VBUS.If 3 –200 ms of Bus Idle Go to A_WAIT_BCONTurn on Host modeA_WAIT_VFALL If ID Interrupt or (A_SESS_VLD/ & b_conn/) Go to A_IDLE43.7.2 OTG dual role B device operationA 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-Bplug 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 tableillustrates.Chapter 43 Universal Serial Bus Full Speed OTG Controller (USBFSOTG)K22F Sub-Family Reference Manual, Rev. 4, 08/2016NXP Semiconductors 1115
