Intel PXA26X - Manual (Page 453)

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 OUT endpoint error status, and the 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 packet that is
corrupted. This status bit is used in the interrupt generation of endpoint 4. To maintain
synchronization, the software must monitor this bit when it services an SOF interrupt and reads the
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
t
X 0 0 0 0 0 0 0 0
Bits Name Description
0 IR8
INTERRUPT REQUEST ENDPOINT 8 (read/write 1 to clear):
1 – Endpoint 8 needs service.
1 IR9
INTERRUPT REQUEST ENDPOINT 9 (read/write 1 to clear):
1 – Endpoint 9needs service.
2 IR10
INTERRUPT REQUEST ENDPOINT 10 (read/write 1 to clear):
1 – Endpoint 10 needs service.
3 IR11
INTERRUPT REQUEST ENDPOINT 11 (read/write 1 to clear):
1 – Endpoint 11 needs service.
4 IR12
INTERRUPT REQUEST ENDPOINT 12 (read/write 1 to clear):
1 – Endpoint 12 needs service.
5 IR13
INTERRUPT REQUEST ENDPOINT 13 (read/write 1 to clear):
1 – Endpoint 13 needs service.
6 IR14
INTERRUPT REQUEST ENDPOINT 14 (read/write 1 to clear):
1 – Endpoint 14 needs service.
7 IR15
INTERRUPT REQUEST ENDPOINT 15 (read/write 1 to clear):
1 – Endpoint 15 needs service.
31:8 — Reserved for future use