C200 datasheet(16/82 Pages) INTEL

16 / 82 page

Errata

Specification Update

Errata

USB Isoch In Transfer Error Issue

Problem:

If a USB full-speed inbound isochronous transaction with a packet length 190 bytes or

greater is started near the end of a microframe the PCH may see more than 189 bytes

in the next microframe.

Implication: If the PCH sees more than 189 bytes for a microframe an error will be sent to software

and the isochronous transfer will be lost. If a single data packet is lost no perceptible

impact for the end user is expected.

Note:

Intel has only observed the issue in a synthetic test environment where precise control

of packet scheduling is available, and has not observed this failure in its compatibility

validation testing.

• Isochronous traffic is periodic and cannot be retried thus it is considered good

practice for software to schedule isochronous transactions to start at the beginning

of a microframe. Known software solutions follow this practice.

• To sensitize the system to the issue additional traffic such as other isochronous

transactions or retries of asynchronous transactions would be required to push the

inbound isochronous transaction to the end of the microframe.

Workaround: None.

Status:

No Plan to Fix.

USB Full-/low-speed Device Removal Issue

Problem:

If two or more USB full-/low-speed devices are connected to the same USB controller,

the devices are not suspended, and one device is removed, one or more of the devices

remaining in the system may be affected by the disconnect.

Implication: The implication is device dependent. A device may experience a delayed transaction,

stall and be recovered via software, or stall and require a reset such as a hot plug to

resume normal functionality.

Workaround: None.

Status:

No Plan to Fix.

C200 Datasheet(PDF) 16 Page - Intel Corporation