*Notice: The information in this document is subject to change without notice
Tsi301
Notes
Tsi301 HyperTransport to PCI User Manual
5-36
Bridge Control
Offset 3Fh–3Eh
Bits
Type
Reset
Description
15:12
R
0h
Reserved.
11
RW
0
DiscardSerrEn - if set, treat a discard timer error as a system error. It can cause
the assertion of either the FATAL_ERR_N or NONFATAL_ERR_N interrupts,
depending on the state of the DiscardSerrFatal bit of the Error Control register
(see “Error Control Offset 67h–64h” on page -23). Not persistent through
warm reset.
10
RC
0
DiscardStat - this bit is set by hardware when a request is dropped due to an
expired discard counter. It may be cleared by writing a 1 to it. Persistent through
warm reset.
9
RW
0
SecDiscardTimer - sets the length of the timer on delayed requests. Once the
initial subrequests of an inbound delayed transaction have completed on
HyperTransport, the timer begins to run. If it expires before the PCI requester
reissues the request, the transaction is dropped from the delayed request buf-
fers. Not persistent through warm reset.
0 = count 2
15
PCI clocks
1 = count 2
10
PCI clocks
8
R
0
PrimDiscardTimer - not meaningful for HyperTransport. Always reads 0.
7
RW
0
FastB2BEn - enables the generation of fast back-to-back transactions when the
HyperTransport PCI bridge is the master on the PCI bus. Not persistent through
warm reset.
6
RW
0
SecBusReset - if written to a 1, hardware will perform a reset sequence on the
secondary bus. Clearing the bit will bring the secondary bus out of reset. Not
persistent through warm reset.
5
RW
0
MstrAbortMode - this bit controls the action taken by the bridge when a transac-
tion that it is forwarding in either direction takes a master abort on the destina-
tion bus. The master abort is indicated on HyperTransport by an error response
with NXA set
• If this bit is clear, writes are allowed to complete
normally on the source bus, and reads have all 1's
returned.
• If it is set, the master abort will be treated as an error,
returning a Target Abort Response (indicated on
HyperTransport by a set error bit without NXA) for
nonposted requests and causing a sideband error
assertion (indicated by asserting the FATAL_ERR_N or
NONFATAL_ERR_N interrupt pins, as enabled) for
posted requests.
Not persistent through warm reset.
4
R
0
Reserved.