Register Map
13-31
USB Function Module
13.2.12
Interrupt Source Register (IRQ_SRC)
The read/clear-only interrupt source register (IRQ_SRC) has for function to
identify and clear the source of the interrupt signaled by a set flag.
Table 13–13. Interrupt Source Register (IRQ_SRC)
Bit
Name
Description
15–11
–
Reserved
10
TXn_Done
Transmit DMA channel n done interrupt flag (non-isochronous)
9
RXn_Cnt
Receive DMA channel n transactions count interrupt flag (non-isochronous)
8
RXn_EOT
Receive DMA channel n end of transfer interrupt flag (non-isochronous)
7
SOF
Start-of-frame interrupt flag
6
–
Reserved
5
EPn_RX
EPn OUT transactions interrupt flag
4
EPn_TX
EPn IN transactions interrupt flag
3
DS_Chg
Device state changed interrupt flag
2
Setup
Setup transaction interrupt flag
1
EP0_RX
EP0 OUT transactions interrupt flag
0
EP0_TX
EP0 IN transactions interrupt flag
Common to all bits:
The local host can only clear a set bit location by writing a 1 into the bit location
(except for Setup bit, which is automatically cleared by the core). A write of 0
has no effect.
When a bit location is set to 1 by the core, an interrupt is signaled to the local
host if the interrupt was enabled.
0: No interrupt
1: Interrupt signaled
Value after local host or USB reset is low, except for the DS_Chg bit, which is
high after a USB reset.