Datasheet
iii
Intel
IXP1250 Network Processor
Contents
1.0
Product Description............................................................................................................9
2.0
Functional Units................................................................................................................11
2.1
Conventions ........................................................................................................11
2.2
StrongARM* Core Microprocessor......................................................................11
2.3
Microengines.......................................................................................................11
2.4
FBI Unit and the IX Bus.......................................................................................12
2.4.1
IX Bus Access Behavior.........................................................................12
2.4.1.1 Reset and Idle Bus Considerations...........................................14
2.5
SDRAM and SRAM Units....................................................................................15
2.5.1
SDRAM Unit...........................................................................................15
2.5.2
SDRAM Bus Access Behavior ...............................................................16
2.5.3
SDRAM Cyclic Redundancy Checking (CRC) .......................................17
2.5.4
SDRAM Error Correction Code (ECC) ...................................................17
2.5.5
SDRAM Configurations ..........................................................................18
2.5.6
SRAM Unit..............................................................................................18
2.5.6.1 SRAM Types Supported............................................................20
2.5.6.2 SRAM Configurations................................................................20
2.5.6.3 BootROM Configurations ..........................................................21
2.5.6.4 SRAM Bus Access Behavior.....................................................21
2.6
PCI Unit...............................................................................................................22
2.6.1
PCI Arbitration and Central Function Support........................................22
2.7
Device Reset.......................................................................................................23
2.7.1
Hardware Initiated Reset........................................................................25
2.7.2
Software Initiated Reset .........................................................................25
2.7.3
PCI Initiated Reset .................................................................................25
2.7.4
Watchdog Timer Initiated Reset.............................................................25
3.0
Signal Description ............................................................................................................26
3.1
Pinout Diagram....................................................................................................26
3.2
Pin Type Legend.................................................................................................27
3.3
Pin Description, Grouped by Function.................................................................28
3.3.1
Processor Support Pins..........................................................................28
3.3.2
SRAM Interface Pins..............................................................................29
3.3.3
SDRAM Interface Pins ...........................................................................31
3.3.4
IX Bus Interface Pins..............................................................................33
3.3.5
General Purpose I/Os.............................................................................37
3.3.6
Serial Port (UART) Pins .........................................................................37
3.3.7
PCI Interface Pins ..................................................................................38
3.3.8
Power Supply Pins .................................................................................41
3.3.9
IEEE 1149.1 Interface Pins....................................................................42
3.3.10 Miscellaneous Test Pins.........................................................................42
3.3.11 Pin Usage Summary ..............................................................................43
3.4
Pin/Signal List......................................................................................................44
3.5
Signals Listed in Alphabetical Order ...................................................................49
3.6
IX Bus Pins Function Listed by Operating Mode.................................................53
3.7
IX Bus Decode Table Listed by Operating Mode Type.......................................63