*Notice: The information in this document is subject to change without notice
Tsi301
Notes
Tsi301 HyperTransport to PCI User Manual
3-20
Because the HyperTransport PCI bridge prefetches read data, it is possible that the error occurred on a
location that the PCI device did not intend to access. If error responses are received for prefetch requests, the
associated data is dropped. The prefetching stops at the point of the error, and the PCI transaction is discon-
nected when it reaches that point. If the PCI device then requests the data again, the request goes back to
HyperTransport. If the error recurs, the response error is passed to PCI.
Once a response reaches the delayed request buffers, it must wait there until the requesting PCI master
reconnects. As soon as the initial HyperTransport request completes and places its data in the buffer, a timer
starts. The timer may be initialized to one of two values, as configured by the SecDiscardTimer bit in the
Bridge Control CSR. If the timer expires before the data is called for, that may be treated as an error.
Slave Errors
— The HyperTransport PCI bridge CSR master only supports accesses within a 32-bit
aligned block. Accesses that span more than one 32-bit block receive HyperTransport error responses, equiv-
alent to a PCI target abort. No other action is taken.
Error responses may also be signaled to HyperTransport because of errors taken when the request was
issued to PCI.
3.11 PCI Errors
3.11.1 PCI System Errors
PCI devices may assert an unrecoverable system error by asserting SERR# on the secondary PCI bus.
Settings for this error are described in Table 3.5.
3.11.2 PCI Master Errors
PCI master errors refers to errors detected by the HyperTransport PCI bridge when acting as a master on
the PCI bus. Master and Target Abort are defined in the
PCI Local Bus Specification, Revision 2.2
.
Error
Log Bit
Fatal
Interrupt
NonFatal
Interrupt
PCI
Response
Match Error
Error/
RespMatchErr
Error/
RespMatchFatalEn
Error/
RespMatch
NonFatalEn
No action
Error without
NXA
Status/
RcvdTgtAbort
Not supported
Target Abort
Error with
NXA
Status/
RcvdMstrAbort
If BrCtrl/
MstrAbortMode = 1,
Target Abort; Else,
complete normally
returning all 1s data
Discard
Timeout
BrCtrl/
DiscardStat
BrCtrl/
DiscardSerrEn &
Error/
DiscardSerrFatal
BrCtrl/
DiscardSerrEn &
!Error/
DiscardSerrFatal
Data dropped; PCI master
must re-request.
Table 3.4 HyperTransport Master Errors CSR Bits
Error
Log Bit
Fatal Int
NonFatal Int
SERR# Assertion
SecStatus/
DetSerr
BrCtrl/SerrEn &
ErrCtrl/
SerrFatalEn
BrCtrl/SerrEn &
!ErrCtrl/
SerrFatalEn
Table 3.5 PCI System Error CSR Bits