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1. Terms and Acronyms
2. Introduction
3. Functional Description
4. Interface Overview
5. Parameters (H-Tile)
6. Parameters (P-Tile and F-Tile)
7. Designing with the IP Core
8. Software Programming Model
9. Registers
10. Troubleshooting/Debugging
11. Multi Channel DMA Intel FPGA IP for PCI Express User Guide Archives
12. Revision History for Multi Channel DMA Intel FPGA IP for PCI Express User Guide
4.1. Port List
4.2. Clocks
4.3. Resets
4.4. Multi Channel DMA
4.5. Bursting Avalon-MM Master (BAM) Interface
4.6. Bursting Avalon-MM Slave (BAS) Interface
4.7. Config Slave Interface (RP only)
4.8. Hard IP Reconfiguration Interface
4.9. Config TL Interface
4.10. Configuration Intercept Interface (EP Only)
4.11. User Functional Level Reset (FLR)
4.12. User Event MSI-X Request Interface
8.1.6.1. ifc_api_start
8.1.6.2. ifc_mcdma_port_by_name
8.1.6.3. ifc_qdma_device_get
8.1.6.4. ifc_num_channels_get
8.1.6.5. ifc_qdma_channel_get
8.1.6.6. ifc_qdma_acquire_channels
8.1.6.7. ifc_qdma_release_all_channels
8.1.6.8. ifc_qdma_device_put
8.1.6.9. ifc_qdma_channel_put
8.1.6.10. ifc_qdma_completion_poll
8.1.6.11. ifc_qdma_request_start
8.1.6.12. ifc_qdma_request_prepare
8.1.6.13. ifc_qdma_descq_queue_batch_load
8.1.6.14. ifc_qdma_request_submit
8.1.6.15. ifc_qdma_pio_read32
8.1.6.16. ifc_qdma_pio_write32
8.1.6.17. ifc_qdma_pio_read64
8.1.6.18. ifc_qdma_pio_write64
8.1.6.19. ifc_qdma_pio_read128
8.1.6.20. ifc_qdma_pio_write128
8.1.6.21. ifc_qdma_pio_read256
8.1.6.22. ifc_qdma_pio_write256
8.1.6.23. ifc_request_malloc
8.1.6.24. ifc_request_free
8.1.6.25. ifc_app_stop
8.1.6.26. ifc_qdma_poll_init
8.1.6.27. ifc_qdma_poll_add
8.1.6.28. ifc_qdma_poll_wait
8.1.6.29. ifc_mcdma_port_by_name
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8.1.2.2. Descriptor Memory Management
At the time of channel initialization, the device allocates the descriptor and data memory.
Descriptor memory
Maximum length of data in descriptor is 1 MB. Link specifies whether the next descriptor is in any other page.
AVST H2D/D2H descriptor
- source address
- Destination address
- Data length
- Start of file (SOF)
- End of file (EOF)
- Descriptor index
- Link
Application need to pass these values to the hardware through the libmqdma.
Data Memory
The user space data page can be much bigger than the normal TLB entry page size of 4 KB. libqdma library implements the allocator to organize the memory.
Following are the hardware registers which the software updates as part of the channel enumeration.
- Q_START_ADDR_L, Q_START_ADDR_H: Contains the physical address of the start of the descriptor array.
- Q_SIZE: Logarithmic value of number of descriptors
- Q_CONS_HEAD_ADDR_L, Q_CONS_HEAD_ADDR_H: Physical address of the head index of the ring, where FPGA sync the value of the head.