*Notice: The information in this document is subject to change without notice
Tsi301
Notes
Tsi301 HyperTransport to PCI User Manual
5-36
3
RW
0
VgaEn - this bit modifies the response by the bridge to VGA compatible
addresses, which are defined as memory addresses in the range 000A_0000h -
000B_FFFFh, and I/O space addresses in the bottom 64KB of PCI I/O space,
where the bottom 10 bits are in the range 3B0h - 3BBh or 3C0h - 3DFh.
Address bits 15:10 of I/O addresses are not decoded, allowing for ISA aliasing
of the above address ranges.
If set, the bridge will forward these addresses from the primary to the secondary
bus and block forwarding them from the secondary to the primary bus; regard-
less of the contents of the memory and I/O range registers, the ISA Enable bit
(in this register), or the VGA Palette Snoop Enable bit (in the Command regis-
ter).
Not persistent through warm reset.
2
RW
0
IsaEn - this bit modifies the response by the bridge to ISA I/O addresses, which
are defined as those addresses in the top 768 bytes of each 1 KB block of the
first 64KB of PCI I/O space.
If this bit is set, it will block forwarding these addresses from the primary to the
secondary bus and cause forwarding of these addresses from the secondary to
the primary bus; regardless of the contents of the IoBase and IoLimit registers.
Not persistent through warm reset.
1
RW
0
SerrEn - this bit controls forwarding of system errors from the secondary inter-
face to the primary interface. If it is set, SERR# on the secondary bus will cause
a system error (indicated by the assertion of the FATAL_ERR_N or
NONFATAL_ERR_N error interrupt pins), assuming that the SERR enable bit is
set for the primary interface in the command register. Not persistent through
warm reset.
0
RW
0
Parity Error Response Enable - enables parity errors to be reported by
P_PERR_N, FATAL_ERR_N or NONFATAL_ERR_N error interrupt. Not per-
sistent through warm reset.
HyperTransport Capability ID
Offset 40h
Bits
Type
Reset
Description
7:0
R
08h
Id - HyperTransport Capability ID assigned by the PCI SIG.
Capability 2
Offset 41h
Bits
Type
Reset
Description
7:0
R
00h
Pointer - pointer to the next capability block. It always points to 0, indicating no
additional capability blocks.
Bridge Control
Offset 3Fh–3Eh<Emphasis> (Continued)
Bits
Type
Reset
Description