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1. Introduction
2. Quick Start Guide
3. Block and Interface Descriptions
4. Parameters
5. Designing with the IP Core
6. Registers
7. Design Example and Testbench
8. Document Revision History for Intel® L- and H-tile Avalon® Memory-mapped+ IP for PCI Express* User Guide
A. Avalon-MM IP Variants Comparison
B. Root Port BFM
C. BFM Procedures and Functions
D. Troubleshooting and Observing the Link Status
E. Root Port Enumeration
2.1. Design Components
2.2. Directory Structure
2.3. Generating the Design Example
2.4. Simulating the Design Example
2.5. Compiling the Design Example and Programming the Device
2.6. Installing the Linux Kernel Driver
2.7. Running the Design Example Application
2.8. Ensuring the Design Example Meets Timing Requirements
6.1.1. Register Access Definitions
6.1.2. PCI Configuration Header Registers
6.1.3. PCI Express Capability Structures
6.1.4. Intel Defined VSEC Capability Header
6.1.5. Uncorrectable Internal Error Status Register
6.1.6. Uncorrectable Internal Error Mask Register
6.1.7. Correctable Internal Error Status Register
6.1.8. Correctable Internal Error Mask Register
C.1. ebfm_barwr Procedure
C.2. ebfm_barwr_imm Procedure
C.3. ebfm_barrd_wait Procedure
C.4. ebfm_barrd_nowt Procedure
C.5. ebfm_cfgwr_imm_wait Procedure
C.6. ebfm_cfgwr_imm_nowt Procedure
C.7. ebfm_cfgrd_wait Procedure
C.8. ebfm_cfgrd_nowt Procedure
C.9. BFM Configuration Procedures
C.10. BFM Shared Memory Access Procedures
C.11. BFM Log and Message Procedures
C.12. Verilog HDL Formatting Functions
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7.1.3.1. Read DMA Example
A Read DMA transfers data from the PCIe address space (system memory) to the Avalon-MM address space. It sends Memory Read TLPs upstream, and writes the completion data to local memory in the Avalon-MM address space using the Read Data Mover's Avalon® -MM write master interface.
The sequence of steps the example design follows to do a Read DMA is:
- Prepare a table of descriptors (padded to 512-bit each) to perform the Read operation and put the table into the system memory.
- Using the BAM, send one descriptor from software containing the address of the descriptor table to the DMA Controller, which forwards it to the Read Data Mover.
- The Read Data Mover fetches the descriptor table and puts it in a FIFO inside the DMA Controller.
- The DMA Controller outputs these descriptors to the Read Data Mover based on the readiness of the Read Data Mover (indicated by an asserted rddm_desc_ready_o or rddm_prio_ready_o signal).
- The Read Data Mover processes the descriptors by fetching data from the system memory, and writing it to the appropriate Avalon-MM memory.
- The last descriptor processed by the Read Data Mover points to an immediate write descriptor (i.e, a descriptor where the data to be written is inside the descriptor itself) in the system memory. This descriptor's destination address is the Avalon® memory address of the DMA Controller's Write Data Mover port. The Read Data Mover fetches this descriptor from system memory and transfers it to the DMA Controller's Write Data Mover Avalon® address.
- The Write Data Mover uses the descriptor from Step 6 to perform an immediate write to the system memory indicating the completion of the Read Data Mover’s data processing.