See the structure of the USB host interrupt system on Figure 1.
There are two kinds of host interrupts: processing, i.e., their generation is part of the normal processing, and exception, i.e., errors (not related to CPU exceptions).
Global Interrupts
The processing host global interrupts are:
- Device Connection (USBHS_HSTISR.DCONNI)
- Device Disconnection (USBHS_HSTISR.DDISCI)
- USB Reset Sent (USBHS_HSTISR.RSTI)
- Downstream Resume Sent (USBHS_HSTISR.RSMEDI)
- Upstream Resume Received (USBHS_HSTISR.RXRSMI)
- Host Start of Frame (USBHS_HSTISR.HSOFI)
- Host Wakeup (USBHS_HSTISR.HWUPI)
- Pipe x (USBHS_HSTISR.PEP_x)
- DMA Channel x (USBHS_HSTISR.DMAxINT)
There is no exception host global interrupt.
Pipe Interrupts
The processing host pipe interrupts are:
- Received IN Data (USBHS_HSTPIPISRx.RXINI)
- Transmitted OUT Data (USBHS_HSTPIPISRx.TXOUTI)
- Transmitted SETUP (USBHS_HSTPIPISRx.TXSTPI)
- Short Packet (USBHS_HSTPIPISRx.SHORTPACKETI)
- Number of Busy Banks (USBHS_HSTPIPISRx.NBUSYBK)
The exception host pipe interrupts are:
- Underflow (USBHS_HSTPIPISRx.UNDERFI)
- Pipe Error (USBHS_HSTPIPISRx.PERRI)
- NAKed (USBHS_HSTPIPISRx.NAKEDI)
- Overflow (USBHS_HSTPIPISRx.OVERFI)
- Received STALLed (USBHS_HSTPIPISRx.RXSTALLDI)
- CRC Error (USBHS_HSTPIPISRx.CRCERRI)
DMA Interrupts
The processing host DMA interrupts are:
- The End of USB Transfer Status (USBHS_HSTDMASTATUSx.END_TR_ST)
- The End of Channel Buffer Status (USBHS_HSTDMASTATUSx.END_BF_ST)
- The Descriptor Loaded Status (USBHS_HSTDMASTATUSx.DESC_LDST)
There is no exception host DMA interrupt.