Intel® PXA26x Processor Family Developer’s Manual 12-43
Universal Serial Bus Device Controller
12.6.12 UDC Frame Number High Register (UFNHR)
The UDC frame number high register holds the three most significant bits of the frame number
contained in the last received SOF packet, the isochronous OU T endp oint er ror stat us, a nd t he SOF
interrupt status/interrupt mask bit.

12.6.12.1 UDC Frame Number MSB (FNMSB)

The UFNHR[FNMSB] is the three most significant bits of the 11-bit frame number contained in
the last received SOF packet. The remaining bits are located in the UFNLR. This information is
used for isochronous transfers. These bits are updated every SOF.

12.6.12.2 Isochronous Packet Error Endpoint 4 (IPE4)

The isochronous packet error for Endpoint 4 is set if Endpoint 4 is loaded with a data pack et that is
corrupted. This status bit is used in the interrupt generation of en dpoint 4. To maintain
synchronization, the software must monitor this bit when it servi ces an SO F inter rupt and reads th e
frame number. This bit is not set if the token packet is corrupted or if the sync or PID fields of the
data packet are corrupted.
Table 12-22. UDC Status / Interrupt Register 1
0h 4060 005C USIR1 Read/Write and Read-Only
Bit 31:8 7 6 5 4 3 2 1 0
Reserved IR15 IR14 IR13 IR12 IR11 IR10 IR9 IR8
Rese
tX 0 0 0 0 0 0 0 0
Bits Name Description
0IR8
INTERRUPT REQUEST ENDPOINT 8 (read/write 1 to clear):
1 – Endpoint 8 needs service.
1IR9
INTERRUPT REQUEST ENDPOINT 9 (read/write 1 to clear):
1 – Endpoint 9needs service.
2IR10
INTERRUPT REQUEST ENDPOINT 10 (read/write 1 to clear):
1 – Endpoint 10 needs service.
3IR11
INTERRUPT REQUEST ENDPOINT 11 (read/write 1 to clear):
1 – Endpoint 11 needs service.
4IR12
INTERRUPT REQUEST ENDPOINT 12 (read/write 1 to clear):
1 – Endpoint 12 needs service.
5IR13
INTERRUPT REQUEST ENDPOINT 13 (read/write 1 to clear):
1 – Endpoint 13 needs service.
6IR14
INTERRUPT REQUEST ENDPOINT 14 (read/write 1 to clear):
1 – Endpoint 14 needs service.
7IR15
INTERRUPT REQUEST ENDPOINT 15 (read/write 1 to clear):
1 – Endpoint 15 needs service.
31:8 Reserved for future use