Microchip Technology DM240015 Data Sheet

DS30009312B-page 274

 2012-2013 Microchip Technology Inc.

The USB OTG module has many conditions that can
be configured to cause an interrupt. All interrupt
sources use the same interrupt vector.

 shows the interrupt logic for the USB

module. There are two layers of interrupt registers in
the USB module. The top level consists of overall USB
status interrupts; these are enabled and flagged in the
U1IE and U1IR registers, respectively. The second
level consists of USB error conditions, which are
enabled and flagged in the U1EIR and U1EIE registers.

An interrupt condition in any of these triggers a USB
Error Interrupt Flag (UERRIF) in the top level. Unlike
the device-level interrupt flags in the IFSx registers,
USB interrupt flags in the U1IR registers can only be
cleared by writing a ‘1’ to the bit position.
Interrupts may be used to trap routine events in a USB
transaction. 

 provides some common

events within a USB frame and their corresponding
interrupts.

DMAEF

DMAEE

BTOEF

BTOEE

DFN8EF

DFN8EE

CRC16EF

CRC16EE

CRC5EF (EOFEF)

CRC5EE (EOFEE)

PIDEF

PIDEE

ATTACHIF

ATTACHIE

RESUMEIF

RESUMEIE

IDLEIF

IDLEIE

TRNIF

TRNIE

SOFIF

SOFIE

URSTIF (DETACHIF)

URSTIE (DETACHIE)

(UERRIF)

UERRIE

Set USB1IF

STALLIF

STALLIE

BTSEF

BTSEE

T1MSECIF

TIMSECIE

LSTATEIF

LSTATEIE

ACTVIF

ACTVIE

SESVDIF

SESVDIE

SESENDIF

SESENDIE

VBUSVDIF

VBUSVDIE

IDIF

IDIE

Second Level (USB Error) Interrupts

Top Level (USB Status) Interrupts

Top Level (USB OTG) Interrupts