NXP Semiconductors freescale K51 Series Reference Manual

USBx_OTGCTL field descriptions (continued)Field Description0 D+ pulldown resistor is not enabled.1 D+ pulldown resistor is enabled.4DMLOWD- Data Line pull-down resistor enable0 D- pulldown resistor is not enabled.1 D- pulldown resistor is enabled.3ReservedThis read-only field is reserved and always has the value zero.2OTGENOn-The-Go pullup/pulldown resistor enable0 If USB_EN is set and HOST_MODE is clear in the Control Register (CTL), then the D+ Data Line pull-up resistors are enabled. If HOST_MODE is set the D+ and D- Data Line pull-down resistors areengaged.1 The pull-up and pull-down controls in this register are used.1–0ReservedThis read-only field is reserved and always has the value zero.43.4.9 Interrupt Status Register (USBx_ISTAT)The Interrupt Status Register contains bits for each of the interrupt sources within theUSB Module. Each of these bits are qualified with their respective interrupt enable bits.All bits of this register are logically OR'd together along with the OTG Interrupt StatusRegister (OTGSTAT) to form a single interrupt source for the processor's interruptcontroller. After an interrupt bit has been set it may only be cleared by writing a one tothe respective interrupt bit. This register contains the value of 0x00 after a reset.Addresses: USB0_ISTAT is 4007_2000h base + 80h offset = 4007_2080hBit 7 6 5 4 3 2 1 0Read STALL ATTACH RESUME SLEEP TOKDNE SOFTOK ERROR USBRSTWrite w1c w1c w1c w1c w1c w1c w1c w1cReset 0 0 0 0 0 0 0 0USBx_ISTAT field descriptionsField Description7STALLStall InterruptIn Target mode this bit is asserted when a STALL handshake is sent by the SIE.In Host mode this bit is set when the USB Module detects a STALL acknowledge during the handshakephase of a USB transaction. This interrupt can be use to determine is the last USB transaction wascompleted successfully or if it stalled.6ATTACHAttach InterruptTable continues on the next page...Chapter 43 Universal Serial Bus OTG Controller (USBOTG)K51 Sub-Family Reference Manual, Rev. 6, Nov 2011Freescale Semiconductor, Inc. 1069