MIPI CSI-2 Intel® FPGA IP User Guide

ID 813926
Date 7/23/2024
Public
Document Table of Contents

2.3.7. Transmitter AXI4-Stream Input Passthrough Interface

This interface carries MIPI CSI-2 packets in the same format as those produced by the CSI-2 receiver output passthrough interface. This interface allows retransmission of received MIPI CSI-2 packets, for example in bridging applications where the IP combines multiple incoming CSI-2 streams into a single outgoing CSI-2 stream.

The IP provides one AXI4-Stream interface per configured virtual channel. When you select multiple interfaces (Number of video streaming interfaces is greater than 1), the IP updates the virtual channel ID in the outgoing packet headers according to the AXI4-Stream channel where the packet is. When you select a single interface, the virtual channel ID in the packet headers passes through unaltered. You can use this configuration either in single-channel systems or where a merged multichannel stream is already formed.

When you select multiple interfaces, the IP multiplexes them at the input. The inputs have no buffering, so your system must consider the periods of backpressure on each channel while the IP processes other channels. For instance, include a FIFO buffer in the pipeline to each channel input.

Table 16.  Transmitter AXI4-Stream Input Passthrough Interface Signals num_VCs indicates the number of virtual channels configured in the IP and channel_width = PPI_data_width × lane_count
Signal Width Direction Description
axi4s_mipi_in_tdata num_VCs × channel_width Input MIPI packet data. VC0 data are placed in the least-significant channel_width bits, with the highest configured VC in the most significant bits.
axi4s_mipi_in_tkeep num_VCs × (channel_width ÷ 8) Input MIPI packet tkeep. VC0 signals are placed in the least-significant channel_width÷8 bits, with the highest configured VC in the most significant bits.
axi4s_mipi_in_tvalid num_VCs Input MIPI packet datavalid. VC0 signals are placed in the least-significant bit, with the highest configured VC in the most significant bit.
axi4s_mipi_in_tuser num_VCs Input

Bit0: AXI4-Stream start of packet

0 = Not start of packet

1 = Start of packet

VC0 signals are placed in the least-significant bit, with the highest configured VC in the most significant bit.

axi4s_mipi_in_tlast num_VCs Input AXI4-Stream end of packet. VC0 signals are placed in the least-significant bit, with the highest configured VC in the most significant bis.
axi4s_mipi_in_tready num_VCs Output AXI4-Stream data ready. VC0 signals are placed in the least-significant bit, with the highest configured VC in the most significant bit.