Intel Acceleration Stack for Intel® Xeon® CPU with FPGAs Core Cache Interface (CCI-P) Reference Manual

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Date 11/04/2019
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Document Table of Contents
Document Table of Contents x
1. Acceleration Stack for Intel® Xeon® CPU with FPGAs Core Cache Interface (CCI-P) Reference Manual
1. Acceleration Stack for Intel® Xeon® CPU with FPGAs Core Cache Interface (CCI-P) Reference Manual x
1.1. About this Document 1.2. Introduction 1.3. CCI-P Interface 1.4. AFU Requirements 1.5. Intel® FPGA Basic Building Blocks 1.6. Device Feature List 1.7. Document Revision History for Intel® Acceleration Stack for Intel® Xeon® CPU with FPGAs Core Cache Interface (CCI-P) Reference Manual
1.1. About this Document x
1.1.1. Intended Audience 1.1.2. Conventions 1.1.3. Related Documentation 1.1.4. Acronym List for Acceleration Stack for Intel® Xeon® CPU with FPGAs Core Cache Interface (CCI-P) Reference Manual 1.1.5. Acceleration Glossary
1.2. Introduction x
1.2.1. FPGA Interface Manager (FIM) 1.2.2. Intel® FPGA Interface Unit (FIU) 1.2.3. Memory and Cache Hierarchy
1.2.2. Intel® FPGA Interface Unit (FIU) x
1.2.2.1. FIU for Intel® FPGA PAC 1.2.2.2. FIU for Intel Integrated FPGA Platform 1.2.2.3. Comparison of FIU Capabilities
1.3. CCI-P Interface x
1.3.1. Signaling Information 1.3.2. Read and Write to Main Memory 1.3.3. Interrupts 1.3.4. UMsg 1.3.5. MMIO Accesses to I/O Memory 1.3.6. CCI-P Tx Signals 1.3.7. Tx Header Format 1.3.8. CCI-P Rx Signals 1.3.9. Multi-Cache Line Memory Requests 1.3.10. Byte Enable Memory Request ( Intel® FPGA PAC D5005) 1.3.11. Additional Control Signals 1.3.12. Protocol Flow 1.3.13. Ordering Rules 1.3.14. Timing Diagram 1.3.15. CCI-P Guidance
1.3.2. Read and Write to Main Memory x
1.3.2.1. Reading from Main Memory 1.3.2.2. Writing to Main Memory
1.3.8. CCI-P Rx Signals x
1.3.8.1. Rx Header and Rx Data Format
1.3.10. Byte Enable Memory Request ( Intel® FPGA PAC D5005) x
1.3.10.1. Mixing Byte Enable and Full Cache Line Accesses
1.3.12. Protocol Flow x
1.3.12.1. Upstream Requests 1.3.12.2. Downstream Requests
1.3.13. Ordering Rules x
1.3.13.1. Memory Requests 1.3.13.2. MMIO Requests
1.3.13.1. Memory Requests x
1.3.13.1.1. Memory Write Fence 1.3.13.1.2. Memory Consistency Explained
1.4. AFU Requirements x
1.4.1. Mandatory AFU CSR Definitions 1.4.2. AFU Discovery Flow 1.4.3. AFU_ID
1. Acceleration Stack for Intel® Xeon® CPU with FPGAs Core Cache Interface (CCI-P) Reference Manual

1.3.14. Timing Diagram

This section provides the timing diagrams for CCI-P interface signals.
Figure 19. Tx Channel 0 and 1 Almost Full Threshold
Note: The TX channel 0 and 1, almost full threshold signals, assert when there is room for only eight more transactions to be accepted. TX channels 0 and 1 must deassert the valid signals up to eight cycles after almost full asserts.
Figure 20. Write Fence Behavior
The WrFence is inserted between WrLine requests. A WrFence response returns from Rx channel 1.
Note: In Figure 20, all of the writes generated before the WrFence are responded to (completed) before any of the writes that arrive after the WrFence are completed.

The WrFence only fences previous writes issued to the VC selected. Chose VA to fence writes across all VCs.

Figure 21. C0 Rx Channel Interleaved between MMIO Requests and Memory Responses
Figure 22. MMIO Read Response Timeout
Note: The AFU responds to MMIO read transactions in a Max response time of 65,536 pClks cycles.
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