USBx_ADDINFO field descriptions (continued)Field Description0IEHOSTThis bit is set if host mode is enabled.33.5.5 Interrupt Status register (USBx_ISTAT)Contains fields for each of the interrupt sources within the USB Module. Each of thesefields are qualified with their respective interrupt enable bits. After an interrupt bit hasbeen set it may only be cleared by writing a one to the respective interrupt bit. Thisregister contains the value of 0x00 after a reset.Address: 4007_2000h base + 80h offset = 4007_2080hBit 7 6 5 4 3 2 1 0Read STALL 0 RESUME SLEEP TOKDNE SOFTOK ERROR USBRSTWrite 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.6ReservedReservedThis field is reserved.This read-only field is reserved and always has the value 0.5RESUMEThis bit is set when a K-state is observed on the DP/DM signals for 2.5 μs. When not in suspend modethis interrupt must be disabled.4SLEEPThis bit is set when the USB Module detects a constant idle on the USB bus for 3 ms. The sleep timer isreset by activity on the USB bus.3TOKDNEThis bit is set when the current token being processed has completed. The processor must immediatelyread the STATUS (STAT) register to determine the EndPoint and BD used for this token. Clearing this bit(by writing a one) causes STAT to be cleared or the STAT holding register to be loaded into the STATregister.2SOFTOKThis bit is set when the USB Module receives a Start Of Frame (SOF) token.1ERRORThis bit is set when any of the error conditions within Error Interrupt Status (ERRSTAT) register occur. Theprocessor must then read the ERRSTAT register to determine the source of the error.0USBRSTThis bit is set when the USB Module has decoded a valid USB reset. This informs the processor that itshould write 0x00 into the address register and enable endpoint 0. USBRST is set after a USB reset hasbeen detected for 2.5 microseconds. It is not asserted again until the USB reset condition has beenremoved and then reasserted.Chapter 33 Universal Serial Bus (USB) FS SubsystemKL27 Sub-Family Reference Manual , Rev. 5, 01/2016Freescale Semiconductor, Inc. 545
