"TX Companion Chip Specification Update" is released.
Apr,2007
- Product Types
-
- TX Companion Chip
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- TC86C001F (GOKU-S)
- TC86C001FG (GOKU-S)
- TC6358TB (PLUM2)
- TC6358TBG (PLUM2)
- Overview
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- This problem occurs when the USB Controller performs isochronous transactions. For isochronous transactions, a frame number is identified within a descriptor (ITD) to indicate the frame in which it is to be transferred. However, frame numbers might not be synchronized between the USB Host Controller and software; if a descriptor was not processed in the frame in which it should have been retired and is processed in a latter frame, the USB Host Controller recognizes the situation as a time error and writes back DATAOVERRUN (4'h8) to the ConditionCode for the ITD. The problem is, when the specific conditions given below are met, the USB Host Controller writes back an incorrect code, 4'h0 indicating NOERROR, to the ConditionCode. (See Section 4.3.2.3.5.3, "Time Errors," on page 29 of the OpenHCI Specification.)
* ITD: Isochronous Transfer Descriptor - This problem occurs only when the USB Host Controller uses the Remote Wakeup function. When the USB Controller detects a fatal error in a USB system (e.g., Master Abort or Target Abort on the PCI Bus), the OHCI core sets the HcInterrupt.UnrecoverableError (UE) bit. If this bit is set with the HcInterrupt Enable.UnrecoverableError (UE) bit set, the OHCI core generates a hardware interrupt. The USB Host Controller can recover from this error by generating a software reset (i.e., by setting HcCommandStatus.HCR to 1'b1) after detection of the interrupt. Then the USB Host Controller moves to the Suspend state (USBSUSPEND). Upon software reset, the OHCI registers are initialized. If a Remote Wakeup is genrerated from a device after the OHCI registers are initialized, the USB Host Controller should normally move to the Resume state (USBRESUME) but remains in the USBSUSPEND state due to a bug.
- This problem occurs when the USB Controller performs isochronous transactions. For isochronous transactions, a frame number is identified within a descriptor (ITD) to indicate the frame in which it is to be transferred. However, frame numbers might not be synchronized between the USB Host Controller and software; if a descriptor was not processed in the frame in which it should have been retired and is processed in a latter frame, the USB Host Controller recognizes the situation as a time error and writes back DATAOVERRUN (4'h8) to the ConditionCode for the ITD. The problem is, when the specific conditions given below are met, the USB Host Controller writes back an incorrect code, 4'h0 indicating NOERROR, to the ConditionCode. (See Section 4.3.2.3.5.3, "Time Errors," on page 29 of the OpenHCI Specification.)
- Details
- TX Companion Chip Specification Update (PDF:113KB)
