Memory Map/Register Definition
MCF548x Reference Manual, Rev. 3
Freescale Semiconductor 29-15

29.2.2.6 USB Interrupt Mask Register (USBIMR)

Setting a bit in the USBIMR masks the corresponding interrupt in the USBISR.

5 RSTSTOP Reset stop. This indicates the end of reset signalling on the USB.
0 Reset signalling has not stopped. Does not imply that reset signalling is occurring, just that no
end-of-reset event has occurred.
1 Reset signalling has stopped.
4 UPDSOF Updated start of frame. This indicates that the current SOF interrupt was the result of the USB
module having to update its internal frame number due to a missing SOF packet.
0 No missing SOF packets.
1 Current SOF was generated by the USB frame timer.
3 RES Resume. This is used to indicate a state change from suspend to resume in the USB module. This
bit only indicates the change from suspended to active mode. Clearing the interrupt has no effect
on the actual state of the USB.
0 Indicates that USB has not left the suspended state (but does not imply that the bus is, or ever
was suspended).
1 USB has left suspend state.
2 SUSP Suspend. This is used to indicate a suspend state in USB. This bit only indicates the change from
active to suspended mode. Clearing the interrupt has no effect on the actual state of the USB.
0 USB is not suspended, or the interrupt was cleared.
1 USB is suspended.
1 FTUNLCK Frame timer lost lock. This is used to indicate when the USB’s internal frame timer has lost its lock
on the SOF packet sequences. This condition occurs when three consecutive SOF packets are
missed by the core.
0 The USB frame timer is locked, or the interrupt was cleared.
1 The USB frame timer lost its lock on the SOF packet sequences.
0 ISOERR Isochronous error. This indicates that a high-speed, high-bandwidth isochronous OUT endpoint
detected a PID sequencing error.
0 No ISOC OUT error, or the interrupt was cleared.
1 ISOC OUT PID sequencing error.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
R Uninitialized
W
Reset Uninitialized
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
R Uninitialized MSOF SOF RSTSTOP UPDSOF RES SUSP FTUNLCK ISOERR
W
Reset Unaffected by Reset 1 1 1 1 1 1 1 1
Reg
Addr
MBAR + 0xB414

Figure 29-7. USB Interrupt Mask Register (USBIMR)

Table 29-6. USBISR Field Descriptions (Continued)

Bits Name Description