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Package Information
May 2005
Intel IXP45X and Intel IXP46X Product Line of Network Processors Datasheet
76
Document Number: 306261-002
Table 17.
Expansion Bus Interface (Sheet 1 of 4)
Name
Power
on
Reset
Normal
After
Reset
Until
Software
Enables
Normal
After
Software
Enables
Type
Description
EX_CLK
Z
VI
I
Input clock signal used to sample all expansion interface inputs and clock all expansion interface
outputs.
EX_ALE
H
VO
VO / Z
TRI
Expansion bus Address-latch enable used for multiplexed address/data bus accesses, as an
Advance pin for Intel synchronous modes of operation/ZBT SRAM mode of operation, and LD_N for
ZBT SRAM. EX_ALE is always used by outbound transfers.
EX_ADDR[24:0]
H
VB
I/O
Expansion bus address used as an output for data accesses over the expansion bus when
executing outbound transactions and used as an input for data accesses over the expansion bus
when executing inbound transactions. Also, used as an input during reset to capture device
configuration. These signals have a weak pull-up resistor attached internally. Based on the desired
configuration, various address signals must be tied low in order for the device to operate in the
desired mode. A 10K ohm pull down resistor is required to override these pull-up resistors. These
pull-ups are disabled when PLL_LOCK is asserted and the IXP45X/IXP46X network processors
drive the signal based upon grant. EX_ADDR is driven by IXP45X/IXP46X network processors
except when grant is asserted to an external master or during reset.
Very Important Note: See Intel IXP45X and Intel IXP46X Product Line of Network
Processors Developer’s Manual for additional details on address strapping.
EX_WR_N
H
VB
I/O
Expansion bus write enable signal is used as an Intel-mode write strobe / Motorola-mode data
strobe (EXP_MOT_DS_N) / TI*-mode data strobe (TI_HDS1_N) / ZBT SRAM mode read/
write_n(ZBT_RD_WR_N) for outbound transactions. This signal is an output for outbound
transactions.
Expansion bus write enable signal is used as a write enable signal to the IXP45X/IXP46X network
processors for inbound transaction support. This signal is an input for inbound transactions.
EX_WR_N is driven by IXP45X/IXP46X network processors unless grant is asserted to an external
master
EX_RD_N
H
VB
I/O
Expansion bus read enable signal is used as an Intel-mode read strobe / Motorola-mode read-not-
write (EXPB_MOT_RNW) / TI mode read-not-write (TI_HR_W_N) / ZBT SRAM mode output enable
(ZBT_OE_N) for outbound transactions. This signal is an output for outbound transactions.
Expansion bus read enable signal is used as a read enable signal to the IXP45X/IXP46X network
processors for inbound transaction support. This signal is an input for inbound transactions.
EX_RD_N is driven by IXP45X/IXP46X network processors unless grant is asserted to an external
master.
NOTE:
This table discusses all features supported on the Intel IXP45X and Intel IXP46X Product Line of Network Processors. For details on feature support listed by