Intel
®
81341 and 81342 I/O Processors
December 2007
Developer’s Manual
Order Number: 315037-002US
139
Address Translation Unit (PCI-X)—Intel
®
81341 and 81342
describes the bus mode and frequency initialization pattern that the ATU
signals on its secondary bus when coming out of
P_RST#
, after having evaluated the
above information.
When operating in Central Resource Mode (PCIX_EP# = 1), the PCI-X initialization
pattern is driven directly from the PCI-X capability field (bits 19:16) in the
Configuration and Status Register - PCSR”
. The default value of this field is determined
by the
PCIX_EP#
,
PCIXM1_100#
,
PCIXM2_100#
straps, as well as the
P_MODE2
,
P_PCIXCAP
, and
P_M66EN
, signals as described in
While
P_RSTOUT#
is asserted the initialization pattern is driven on the PCI bus.
Software can override the default pattern by writing a new value to PCSR[19:16],
before clearing the Central Resource PCI Bus Reset field (bit 21) in the
Configuration and Status Register - PCSR”
.
When
P_RSTOUT#
is asserted any time after initial power on, software must enforce
the 1ms reset assertion time (T
rst
) required in the PCI specifications.
When operating as an endpoint (
PCIX_EP#
= 0), PCSR[19:16] contains the
initialization pattern captured off the bus during
P_RST#
.
Table 21. PCI-X Initialization Pattern
PERR#
DEVSEL#
STOP#
TRDY#
Mode
a
a. 81341 and 81342 supports neither PCI-X 533 Mode nor ECC in Mode 1.
Clock Period
(Ns)
Clock Frequency
(MHz)
Maxim
um
Minimu
m
Minimu
m
Maxim
um
Deasserted Deasserted Deasserted Deasserted
PCI 33
60
30
16
33
PCI 66
30
15
33
66
Deasserted Deasserted Deasserted Asserted
PCI-X
Mode 1
20
15
50
66
Deasserted Deasserted
Asserted
Deasserted
PCI-X
Mode 1
15
10
66
100
Deasserted Deasserted
Asserted
Asserted
PCI-X
Mode 1
10
7.5
100
133
Deasserted
Asserted
Deasserted Deasserted
PCI-X
Mode 1
Reserved
Deasserted
Asserted
Deasserted Asserted
PCI-X
Mode 1
Deasserted
Asserted
Asserted
Deasserted
PCI-X
Mode 1
Deasserted
Asserted
Asserted
Asserted
PCI-X
Mode 1
Asserted
Deasserted Deasserted Deasserted PCI-X 266
(Mode 2)
Asserted
Deasserted Deasserted Asserted
PCI-X 266
b
(Mode 2)
b. The
P_CLK[3:0]
frequency and associated initialization pattern in PCI-X 266 mode for is selected in the
Configuration and Status Register - PCSR” on page 183
20
15
50
66
Asserted
Deasserted
Asserted
Deasserted PCI-X 266
(Mode 2)
15
10
66
100
Asserted
Deasserted
Asserted
Asserted
PCI-X 266
(Mode 2)
10
7.5
100
133
Asserted
Asserted
Deasserted Deasserted
PCI-X
Reserved
Asserted
Asserted
Deasserted Asserted
PCI-X
Asserted
Asserted
Asserted
Deasserted
PCI-X
Asserted
Asserted
Asserted
Asserted
PCI-X