PRIXP423BB Intel, PRIXP423BB Datasheet - Page 28
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PRIXP423BB
Manufacturer Part Number
PRIXP423BB
Description
IC NETWRK PROCESSR 266MHZ 492BGA
Manufacturer
Intel
Specifications of PRIXP423BB
Processor Type
Network
Features
XScale Core
Speed
266MHz
Voltage
1.3V
Mounting Type
Surface Mount
Package / Case
492-BGA
Core Operating Frequency
533MHz
Package Type
BGA
Pin Count
492
Mounting
Surface Mount
Operating Temperature (max)
85C
Operating Temperature (min)
-40C
Operating Temperature Classification
Industrial
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
869741
Available stocks
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Part Number
Manufacturer
Quantity
Price
2.2.2
Intel
Datasheet
28
®
IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
The memory pipe has eight stages:
The MAC pipe has six to nine stages:
The MAC pipe supports a data-dependent early terminate where stages MAC 2, MAC 3,
and/or MAC 4 are bypassed.
Deep pipes promote high instruction execution rates only when a means exists to
successfully predict the outcome of branch instructions. The branch target buffer
provides such a means.
Branch Target Buffer (BTB)
Each entry of the 128-entry BTB contains the address of a branch instruction, the
target address associated with the branch instruction, and a previous history of the
branch being taken or not taken. The history is recorded as one of four states:
The BTB can be enabled or disabled via Coprocessor 15, Register 1.
When the address of the branch instruction hits in the BTB and its history is strongly or
weakly taken, the instruction at the branch target address is fetched. When its history
is strongly or weakly not-taken, the next sequential instruction is fetched. In either
case the history is updated.
Data associated with a branch instruction enters the BTB the first time the branch is
taken. This data enters the BTB in a slot with a history of strongly not-taken
(overwriting previous data when present).
• Branch Target Buffer (BTB)/Fetch 1
• Fetch 2
• Decode
• Register File/Shift
• ALU Execute
• State Execute
• Integer Writeback
• The first five stages of the Integer pipe (BTB/Fetch 1 through ALU Execute)
• Data Cache 1
• Data Cache 2
• Data Cache Writeback
• The first four stages of the Integer pipe (BTB/Fetch 1 through Register File/ Shift)
• MAC 1
• MAC 2
• MAC 3
• MAC 4
• Data Cache Writeback
• Strongly
. . . then finish with the following memory stages:
. . . then finish with the following MAC stages:
taken
• Weakly taken
Intel
®
IXP42X product line and IXC1100 control plane processors
• Weakly not
taken
Document Number: 252479-006US
• Strongly not taken
August 2006