August; Isochronous Packet Error Endpoint 4 (Ipe4); Isochronous Packet Error Endpoint 9 (Ipe9); Isochronous Packet Error Endpoint 14 (Ipe14) - Intel IXP45X Developer's Manual

USB 1.1 Device Controller—Intel
Processors
8.5.22.2

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.
8.5.22.3

Isochronous Packet Error Endpoint 9 (IPE9)

The isochronous packet error for Endpoint 9 is set if Endpoint 9 is loaded with a data
packet that is corrupted. This status bit is used in the interrupt generation of Endpoint
9.
To maintain synchronization, software must monitor this bit when it services the 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.
8.5.22.4

Isochronous Packet Error Endpoint 14 (IPE14)

The isochronous packet error for Endpoint 14 is set if Endpoint 14 is loaded with a data
packet that is corrupted. This status bit is used in the interrupt generation of Endpoint
14.
To maintain synchronization, software must monitor this bit when it services the 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.
8.5.22.5

Start of Frame Interrupt Mask (SIM)

The UFNHR[SIM] bit is used to mask or enable the SOF interrupt request. When
UFNHR[SIM]=1, the interrupt is masked and the SIR bit is not allowed to be set. When
UFNHR[SIM]=0, the interrupt is enabled and when an interruptible condition occurs in
the receiver, the UFNHR[SIR] bit is set.
Setting UFNHR[SIM] to a 1 does not affect the current state of UFNHR[SIR]. It only
blocks future zero to one transitions of UFNHR[SIR].
8.5.22.6

Start of Frame Interrupt Request (SIR)

The interrupt request bit is set if the UFNHR[SIM] bit is cleared and an SOF packet is
received.
The UFNHR[SIR] bit is cleared by writing a 1 to it.

August 2006

Order Number: 306262--, Revision: 004US
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IXP45X and Intel IXP46X Product Line of Network
Intel
® ®
IXP45X and Intel IXP46X Product Line of Network Processors
Developer's Manual
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