MIPI CSI-2 Intel® FPGA IP User Guide

ID 813926
Date 7/08/2024
Public
Document Table of Contents

4.3.5. Limitations and Known Issues

The MIPI CSI-2 Intel® FPGA IP supports the mandatory feature set of the MIPI CSI-2 specification version 3.0 and the MIPI D-PHY specification version 2.5.

Altera recommends that you read the information in the MIPI D-PHY Intel® FPGA IP User Guide, which describes the supported features in Agilex™ 5 FPGAs and the MIPI D-PHY IP. For a successful implementation, follow the guidance on D-PHY pin locations .

In this release, the MIPI CSI-2 Intel® FPGA IP provides support for between one and four virtual channels. The IP does not support 4-bit virtual channel IDs (VCIDs) using CSI-2 virtual channel extension (VCX) signaling. The IP does not process the additional 12 virtual channels added by VCX (VCIDs 4 to 15) and drops any video data using these extended VCIDs. Packet headers must contain 6-bit ECC and 2-bit VC. The receiver supports up to four virtual channels in all data types except YUV420 formats, where one virtual channel only is supported.

Video line length and RX AXI-S line blanking must be an integer multiple of the CSI-2 data type packing multiple. For example, multiples of four pixels for RAW10, where four 10-bit pixels are packed into five bytes. The MIPI CSI-2 specification defines the packet data size constraints for each data type.

When operating with relatively low DPHY line rates, e.g. below 400 Mbps, the MIPI CSI-2 receiver may not produce a video output. If this is observed, it may be resolved by increasing the TCLK-POST or THS-TRAIL values on your CSI-2 source.

The MIPI CSI-2 transmitter operating in passthrough may prevent the transmitter from producing an output on the DPHY interface when running on hardware.