User manual
Table Of Contents
- Intel® IXP2800 Network Processor
- Copyright
- Contents
- Introduction 1
- Technical Description 2
- 2.1 Overview
- 2.2 Intel XScale® Core Microarchitecture
- 2.3 Microengines
- 2.4 DRAM
- 2.5 SRAM
- 2.6 Scratchpad Memory
- 2.7 Media and Switch Fabric Interface
- 2.8 Hash Unit
- 2.9 PCI Controller
- 2.10 Control and Status Register Access Proxy
- 2.11 Intel XScale® Core Peripherals
- 2.12 I/O Latency
- 2.13 Performance Monitor
- Intel XScale® Core 3
- 3.1 Introduction
- 3.2 Features
- 3.3 Memory Management
- 3.4 Instruction Cache
- 3.5 Branch Target Buffer (BTB)
- 3.6 Data Cache
- 3.6.1 Overviews
- 3.6.2 Data Cache and Mini-Data Cache Operation
- 3.6.3 Data Cache and Mini-Data Cache Control
- 3.6.4 Reconfiguring the Data Cache as Data RAM
- 3.6.5 Write Buffer/Fill Buffer Operation and Control
- 3.7 Configuration
- 3.8 Performance Monitoring
- 3.9 Performance Considerations
- 3.9.1 Interrupt Latency
- 3.9.2 Branch Prediction
- 3.9.3 Addressing Modes
- 3.9.4 Instruction Latencies
- 3.9.4.1 Performance Terms
- 3.9.4.2 Branch Instruction Timings
- 3.9.4.3 Data Processing Instruction Timings
- 3.9.4.4 Multiply Instruction Timings
- 3.9.4.5 Saturated Arithmetic Instructions
- 3.9.4.6 Status Register Access Instructions
- 3.9.4.7 Load/Store Instructions
- 3.9.4.8 Semaphore Instructions
- 3.9.4.9 Coprocessor Instructions
- 3.9.4.10 Miscellaneous Instruction Timing
- 3.9.4.11 Thumb Instructions
- 3.10 Test Features
- 3.11 Intel XScale® Core Gasket Unit
- 3.12 Intel XScale® Core Peripheral Interface
- 3.12.1 XPI Overview
- 3.12.2 UART Overview
- 3.12.3 UART Operation
- 3.12.4 Baud Rate Generator
- 3.12.5 General Purpose I/O (GPIO)
- 3.12.6 Timers
- 3.12.7 Slowport Unit
- Microengines 4
- DRAM 5
- SRAM Interface 6
- SHaC - Unit Expansion 7
- Media and Switch Fabric Interface 8
- 8.1 Overview
- 8.2 Receive
- 8.3 Transmit
- 8.4 RBUF and TBUF Summary
- 8.5 CSIX Flow Control Interface
- 8.6 Deskew and Training
- 8.7 CSIX Startup Sequence
- 8.8 Interface to Command and Push and Pull Buses
- 8.9 Receiver and Transmitter Interoperation with Framers and Switch Fabrics
- 8.9.1 Receiver and Transmitter Configurations
- 8.9.2 System Configurations
- 8.9.2.1 Framer, Single Network Processor Ingress and Egress, and Fabric Interface Chip
- 8.9.2.2 Framer, Dual Network Processor Ingress, Single Network Processor Egress, and Fabric Interface Chip
- 8.9.2.3 Framer, Single Network Processor Ingress and Egress, and CSIX-L1 Chips for Translation and Fabric Interface
- 8.9.2.4 CPU Complex, Network Processor, and Fabric Interface Chip
- 8.9.2.5 Framer, Single Network Processor, Co-Processor, and Fabric Interface Chip
- 8.9.3 SPI-4.2 Support
- 8.9.4 CSIX-L1 Protocol Support
- 8.9.5 Dual Protocol (SPI and CSIX-L1) Support
- 8.9.6 Transmit State Machine
- 8.9.7 Dynamic De-Skew
- 8.9.8 Summary of Receiver and Transmitter Signals
- PCI Unit 9
- 9.1 Overview
- 9.2 PCI Pin Protocol Interface Block
- 9.2.1 PCI Commands
- 9.2.2 IXP2800 Network Processor Initialization
- 9.2.3 PCI Type 0 Configuration Cycles
- 9.2.4 PCI 64-Bit Bus Extension
- 9.2.5 PCI Target Cycles
- 9.2.6 PCI Initiator Transactions
- 9.2.7 PCI Fast Back-to-Back Cycles
- 9.2.8 PCI Retry
- 9.2.9 PCI Disconnect
- 9.2.10 PCI Built-In System Test
- 9.2.11 PCI Central Functions
- 9.3 Slave Interface Block
- 9.4 Master Interface Block
- 9.5 PCI Unit Error Behavior
- 9.5.1 PCI Target Error Behavior
- 9.5.1.1 Target Access Has an Address Parity Error
- 9.5.1.2 Initiator Asserts PCI_PERR_L in Response to One of Our Data Phases
- 9.5.1.3 Discard Timer Expires on a Target Read
- 9.5.1.4 Target Access to the PCI_CSR_BAR Space Has Illegal Byte Enables
- 9.5.1.5 Target Write Access Receives Bad Parity PCI_PAR with the Data
- 9.5.1.6 SRAM Responds with a Memory Error on One or More Data Phases on a Target Read
- 9.5.1.7 DRAM Responds with a Memory Error on One or More Data Phases on a Target Read
- 9.5.2 As a PCI Initiator During a DMA Transfer
- 9.5.2.1 DMA Read from DRAM (Memory-to-PCI Transaction) Gets a Memory Error
- 9.5.2.2 DMA Read from SRAM (Descriptor Read) Gets a Memory Error
- 9.5.2.3 DMA from DRAM Transfer (Write to PCI) Receives PCI_PERR_L on PCI Bus
- 9.5.2.4 DMA To DRAM (Read from PCI) Has Bad Data Parity
- 9.5.2.5 DMA Transfer Experiences a Master Abort (Time-Out) on PCI
- 9.5.2.6 DMA Transfer Receives a Target Abort Response During a Data Phase
- 9.5.2.7 DMA Descriptor Has a 0x0 Word Count (Not an Error)
- 9.5.3 As a PCI Initiator During a Direct Access from the Intel XScale® Core or Microengine
- 9.5.3.1 Master Transfer Experiences a Master Abort (Time-Out) on PCI
- 9.5.3.2 Master Transfer Receives a Target Abort Response During a Data Phase
- 9.5.3.3 Master from the Intel XScale® Core or Microengine Transfer (Write to PCI) Receives PCI_PERR_L on PCI Bus
- 9.5.3.4 Master Read from PCI (Read from PCI) Has Bad Data Parity
- 9.5.3.5 Master Transfer Receives PCI_SERR_L from the PCI Bus
- 9.5.3.6 Intel XScale® Core Microengine Requests Direct Transfer when the PCI Bus is in Reset
- 9.5.1 PCI Target Error Behavior
- 9.6 PCI Data Byte Lane Alignment
- Clocks and Reset 10
- 10.1 Clocks
- 10.2 Synchronization Between Frequency Domains
- 10.3 Reset
- 10.4 Boot Mode
- 10.5 Initialization
- Performance Monitor Unit 11
- 11.1 Introduction
- 11.2 Interface and CSR Description
- 11.3 Performance Measurements
- 11.4 Events Monitored in Hardware
- 11.4.1 Queue Statistics Events
- 11.4.2 Count Events
- 11.4.3 Design Block Select Definitions
- 11.4.4 Null Event
- 11.4.5 Threshold Events
- 11.4.6 External Input Events
- 11.4.6.1 XPI Events Target ID(000001) / Design Block #(0100)
- 11.4.6.2 SHaC Events Target ID(000010) / Design Block #(0101)
- 11.4.6.3 IXP2800 Network Processor MSF Events Target ID(000011) / Design Block #(0110)
- 11.4.6.4 Intel XScale® Core Events Target ID(000100) / Design Block #(0111)
- 11.4.6.5 PCI Events Target ID(000101) / Design Block #(1000)
- 11.4.6.6 ME00 Events Target ID(100000) / Design Block #(1001)
- 11.4.6.7 ME01 Events Target ID(100001) / Design Block #(1001)
- 11.4.6.8 ME02 Events Target ID(100010) / Design Block #(1001)
- 11.4.6.9 ME03 Events Target ID(100011) / Design Block #(1001)
- 11.4.6.10 ME04 Events Target ID(100100) / Design Block #(1001)
- 11.4.6.11 ME05 Events Target ID(100101) / Design Block #(1001)
- 11.4.6.12 ME06 Events Target ID(100110) / Design Block #(1001)
- 11.4.6.13 ME07 Events Target ID(100111) / Design Block #(1001)
- 11.4.6.14 ME10 Events Target ID(110000) / Design Block #(1010)
- 11.4.6.15 ME11 Events Target ID(110001) / Design Block #(1010)
- 11.4.6.16 ME12 Events Target ID(110010) / Design Block #(1010)
- 11.4.6.17 ME13 Events Target ID(110011) / Design Block #(1010)
- 11.4.6.18 ME14 Events Target ID(110100) / Design Block #(1010)
- 11.4.6.19 ME15 Events Target ID(110101) / Design Block #(1010)
- 11.4.6.20 ME16 Events Target ID(100110) / Design Block #(1010)
- 11.4.6.21 ME17 Events Target ID(110111) / Design Block #(1010)
- 11.4.6.22 SRAM DP1 Events Target ID(001001) / Design Block #(0010)
- 11.4.6.23 SRAM DP0 Events Target ID(001010) / Design Block #(0010)
- 11.4.6.24 SRAM CH3 Events Target ID(001011) / Design Block #(0010)
- 11.4.6.25 SRAM CH2 Events Target ID(001100) / Design Block #(0010)
- 11.4.6.26 SRAM CH1 Events Target ID(001101) / Design Block #(0010)
- 11.4.6.27 SRAM CH0 Events Target ID(001110) / Design Block #(0010)
- 11.4.6.28 DRAM DPLA Events Target ID(010010) / Design Block #(0011)
- 11.4.6.29 DRAM DPSA Events Target ID(010011) / Design Block #(0011)
- 11.4.6.30 IXP2800 Network Processor DRAM CH2 Events Target ID(010100) / Design Block #(0011)
- 11.4.6.31 IXP2800 Network Processor DRAM CH1 Events Target ID(010101) / Design Block #(0011)
- 11.4.6.32 IXP2800 Network Processor DRAM CH0 Events Target ID(010110) / Design Block #(0011)
Hardware Reference Manual 331
Intel
®
IXP2800 Network Processor
PCI Unit
9.2.11.3 PCI Internal Arbiter
The PCI unit contains a PCI bus arbiter that supports two external masters in addition to the PCI
Unit’s initiator interface. To enable the PCI arbiter, the CFG_PCI_ARB(GPIO[2]) strapping pin
must be 1 during reset. As shown in Figure 120, the local bus request and grant pair become
externally not visible. These signals will be made available to external debug pins for debug
purpose.
The arbiter uses a simple round-robin priority algorithm, The arbiter asserts the grant signal
corresponding to the next request in the round-robin during the current executing transaction on the
PCI bus (this is also called hidden arbitration). If the arbiter detects that an initiator has failed to
assert frame_l after 16 cycles of both grant assertion and PCI bus idle condition, the arbiter de-
asserts the grant. That master does not receive any more grants until it de-asserts its request for at
least one PCI clock cycle. Bus parking is implemented in that the last bus grant will stay asserted if
no request is pending.
To prevent bus contention, if the PCI bus is idle, the arbiter never asserts one grant signal in the
same PCI cycle in which it de-asserts another. It de-asserts one grant, and then asserts the next
grant after one full PCI clock cycle has elapsed to provide for bus driver turnaround.
Figure 120. PCI Arbiter Configuration Using CFG_PCI_ARB(GPIO[2])
Pin CFG_PCI_ARB(GPIO[2]) = 0 (during reset) CFG_PCI_ARB(GPIO[2]) = 1(during reset)
GNT_L[0]
GNT_L[1]
REQ_L[0]
REQ_L[1]
PCI Bus Grant Input to IXP2800 Network Processor
Not Used, Float
PCI Bus Request Output from IXP2800 Network Processor
Not Used, Tied High
PCI Bus Grant Output to Master 1
PCI Bus Grant Output to Master 2
PCI Bus Request Input from Master 1
PCI Bus Request Input from Master 1
A9767-03
PCI Master
State Machine
PCI Arbiter
GNT_L
GNT_L[2:0]
REQ_L[2:0]
GNT_L[1]
GNT_L[0]
CFG_PCI_ARB
REQ_L[0]
REQ_L[1]
REQ_L
PCI UNIT
0
1