1. About the CPRI Intel® FPGA IP Core 2. Getting Started with the CPRI Intel® FPGA IP Core 3. Functional Description 4. CPRI Intel® FPGA IP Core Signals 5. CPRI Intel® FPGA IP Core Registers 6. CPRI Intel® FPGA IP User Guide Archives 7. Document Revision History for the CPRI Intel® FPGA IP User Guide
2.1. Installation and Licensing 2.2. Generating CPRI Intel® FPGA IP Core 2.3. CPRI Intel® FPGA IP File Structure 2.4. CPRI Intel® FPGA IP Core Parameters 2.5. Integrating Your Intel® FPGA IP Core in Your Design: Required External Blocks 2.6. Simulating Intel FPGA IP Cores 2.7. Understanding the Testbench 2.8. Running the Design Example 2.9. Compiling the Full Design and Programming the FPGA
2.5.1. Adding the Transceiver TX PLL IP Core 2.5.2. System PLL Connections for the Intel Agilex® 7 F-tile Variations 2.5.3. Adding the Reset Controller 2.5.4. Adding the Transceiver Reconfiguration Controller 2.5.5. Adding the Off-Chip Clean-Up PLL 2.5.6. Adding and Connecting the Single-Trip Delay Calibration Blocks 2.5.7. Transceiver PLL Calibration 2.5.8. Reference and System PLL Clock for your IP Design
3.1. Interfaces Overview 3.2. CPRI Intel® FPGA IP Core Clocking Structure 3.3. CPRI Intel® FPGA IP Core Reset Requirements 3.4. Start-Up Sequence Following Reset 3.5. AUX Interface 3.6. Direct IQ Interface 3.7. Ctrl_AxC Interface 3.8. Direct Vendor Specific Access Interface 3.9. Real-Time Vendor Specific Interface 3.10. Direct HDLC Serial Interface 3.11. Direct L1 Control and Status Interface 3.12. L1 Debug Interface 3.13. Media Independent Interface (MII) to External Ethernet Block 3.14. Gigabit Media Independent Interface (GMII) to External Ethernet Block 3.15. CPU Interface to CPRI Intel® FPGA IP Registers 3.16. Auto-Rate Negotiation 3.17. Extended Delay Measurement 3.18. Deterministic Latency and Delay Measurement and Calibration 3.19. CPRI Intel® FPGA IP Transceiver and Transceiver Management Interfaces 3.20. Testing Features
3.19.1. CPRI Link 3.19.2. Main Transceiver Clock and Reset Signals 3.19.3. Arria V, Arria V GZ, Cyclone V, and Stratix V Transceiver Reconfiguration Interface 3.19.4. Intel® Arria® 10, Intel® Stratix® 10, and Intel Agilex® 7 Transceiver Reconfiguration Interface 3.19.5. RS-FEC Interface 3.19.6. Interface to the External Reset Controller 3.19.7. Interface to the External PLL 3.19.8. Transceiver Debug Interface
22.214.171.124. Rx Path Delay
The Rx path delay is the cumulative delay from the arrival of the first bit of a 10 ms radio frame on the CPRI Rx interface to the start of transmission of the radio frame on the AUX interface.
Figure 60. Rx Path Delay to AUX Output in CPRI Intel® FPGA IP
The Rx path delay to the AUX interface is the sum of the following delays:
- The link delay is the delay between the arrival of the first bit of a 10 ms radio frame on the CPRI Rx interface and the CPRI IP internal transmission of the radio frame pulse from the CPRI protocol interface receiver.
- Rx transceiver latency is a fixed delay through the deterministic latency path of the Rx transceiver. Its duration depends on the device family and the current CPRI line bit rate. This delay includes comma alignment and byte alignment within the transceiver.
- Fixed delay from the Rx transceiver to the Rx elastic buffer. This delay depends on the device family and the CPRI line bit rate.
Note: In IP core variations that target an Intel® Stratix® 10 device, you must also add the delay through the Stratix 10 hard FIFOs in the Rx path.
- Delay through the clock synchronization FIFO, as well as the phase difference between the recovered receive clock and the core clock cpri_clkout. The "Extended Delay Measurement" section shows how to calculate the delay in the CPRI IP core Rx elastic buffer, which includes the phase difference delay.
- Byte alignment delay that can occur as data is shifted out of the receiver. This variable delay appears in the rx_byte_delay field of the RX_DELAY register. When the value in rx_byte_delay is non-zero, a byte alignment delay of one cpri_clkout cycle occurs in the Rx path.
- Variable delay introduced by the optional single-trip delay calibration feature in CPRI link slave IP cores.
- Variable delay introduced by the optional round-trip delay calibration feature in CPRI link master IP cores.
- Delay from the CPRI low-level receiver block to the AUX interface. This delay depends on the device family and the CPRI line bit rate.
Did you find the information on this page useful?