User Manual
BCM1250/BCM1125/BCM1125H
10/21/02
B r o a d c o m C o r p o r a t i o n
Document
1250_1125-UM100CB-R
Section 8: PCI Bus and HyperTransport Fabric Page
241
Each map table entry contains the mapping address and flags. There are 16 entries in the table, and it is
indexed by bits [23:20] of the PCI address.
Table 133: PCI Feature Control Register - Offset 40 Bits [31:16]
Bits
Name
Default
Description
0
bar4_en
R/W 1’b1
This bit must be set to enable accesses through BAR 4 in Host Mode. (default
enabled).
1
bar5_en
R/W 1’b1
This bit must be set to enable accesses through BAR 5 in Host Mode. (default
enabled).
2
ptp_en
R/W 1’b0
This bit must be set to enable PCI-HyperTransport peer-to-peer transfers
(default disabled).
3
adapt_retry_en
R/W 1’b0
This bit must be set to enable the adaptive retry (See
)
6:4
min_tar_retry
R/W 3’b011
Sets the minimum number of cycles before a retry is issued when the adaptive
retry algorithm is used.
10:7
nom_tar_retry
R/W 4’b1011 Along with the upper bits from the PCI Adaptive Extend register this sets the
nominal number of cycles before a retry is issued when the adaptive retry
algorithm is used.
15:11
max_tar_retry
R/W
5’b01111
Along with the upper bits from the PCI Adaptive Extend register this sets the
maximum number of cycles before a retry is issued when the adaptive retry
algorithm is used.
Table 134: PCI BAR0 Map Table Entry - Offset 44 – 80
Bits
Name
Default
Description
0
enable
1'b0
This bit must be set to enable the mapping. If it is clear the PCI interface will not
assert DEVSEL# to accept the request.
1
send_ldt
1'b0
If this bit is set then the request will be forwarded to the HyperTransport fabric
(regardless of what the address is). If this bit is clear the request is sent into the
BCM1250.
2
l2ca
1'b0
If this bit is set then the L2CA flag will be set when an access is made to the
ZBbus through this entry. This requests that the cache block be allocated in the
L2 cache.
3
endian
1'b0
If the system is configured for big endian operation and this bit is set the match
bits policy will be used, if this bit is clear the match bytes policy is used. If the
system is configured little endian this bit is ignored.
11:4 reserved
8'b0 Reserved
31:12
addr
20'b0
These bits provide bits 39:20 of the internal address. Bits 19:0 are copied from
the PCI address.
Table 135: PCI Additional Status and Control Register - Offset 88 Bits [31:0]
Bits
Name
Default
Description
0
hotplug_en
R/W 1’b0
If this bit is set the hotplug function in the internal PCI arbiter is enabled.
1
serr_det
R/C 1’b0
Set when some other device on the PCI bus asserts SERR (a PCI error interrupt is
also raised). Software must write a 1 to this bit to clear it and remove the interrupt.
2
TrdyErr
R/C 1’b0
Set when a transfer is aborted because TRDY was not asserted within the
TrdyTimeout (See
). The TrdyIntEn bit must be set in order
for this bit to be set. Software must write a 1 to this bit to clear it and remove the
interrupt.