I/O Planning - 5.1 English

MIPI CSI-2 Receiver Subsystem Product Guide (PG232)

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5.1 English

The MIPI CSI-2 RX Subsystem provides an I/O planner feature for I/O selection. In the Pin Assignment tab, dedicated byte clocks (DBC) or quad byte clocks (QBC) are listed for the clock lane for the selected HP I/O bank. For the QBC clock lane, all of the I/O pins are listed for data lane I/O selection but for the DBC clock lane only the byte group I/O pins are listed for data lane I/O selection.

Eight MIPI CSI-2 RX Subsystem IP cores can be implemented per IO bank based on BITSLICE and BITSLICE_CONTROL instances in the UltraScale+ devices.

IMPORTANT: If the RX data lane I/O pins are selected non-contiguously then an additional one, two, or three I/O pins (RX_BITSLICE) are automatically used for clock/Strobe propagation. Therefore, it is recommended that you select adjacent I/O pins for the RX configuration to make efficient use of the I/O. The propagation of strobes to the RX data pins follows the inter-byte and inter-nibble clocking rules given in the UltraScale Architecture SelectIO Resources User Guide (UG571) [Ref 16] . All lanes of a particular MIPI CSI-2 RX Subsystem instance need to be in the same HP IO bank which is automatically controlled by the Pin Assignment tab of the XGUI for Ultrascale+ devices. Multiple MIPI CSI-2 RX Subsystem instances sharing clocking resources also need to be in the same HP IO bank.

The MIPI CSI-2 RX Subsystem GUI does not have an I/O Assignment tab for Versal ® ACAP. Instead you need to use consolidated I/O planning in the main Vivado IDE Planning, that is, nibble planner. You can select any I/O for the data lanes for the selected XPIO bank. For the clock lane, select the clock capable pin that is the 0 th pin of a nibble for the selected XPIO bank. Detailed steps on how to perform the Vivado IDE planning is detailed under section “I/O Planning for Versal ACAP Advanced IO Wizard” in the Advanced IO Wizard LogiCORE IP Product Guide (PG320) [Ref 20] .

While selecting IOs in a bank across nibbles, you need to ensure the Inter-nibble, Inter-byte clock guidelines are followed. See the “Clocking” section in the Versal ACAP SelectIO Resources Architecture Manual (AM010) [Ref 21] . For more details on Versal ACAP IO planning, see MIPI D-PHY LogiCORE IP Product Guide [Ref 3] .

This Figure shows the eight MIPI CSI-2 RX Subsystem IP cores configured with one clock lane and two data lanes and implemented in a single HP/XP I/O bank.

The csi2_rx_master is configured with Include Shared Logic in core option and the remaining cores are configured with Include Shared Logic in example design . The constant clkoutphy signal is generated within the PLL of the csi2_rx_master core irrespective of line rate and is shared with all other slave IP cores ( csi2_rx_slave1 to csi2_rx_slave7 ) with different line rates.

Note: The master and slave cores can be configured with a different line rate when sharing clkoutphy within the IO bank.

Figure 3-5: MIPI CSI-2 RX Subsystem Core Shared Logic Use Case for Single I/O Bank

X-Ref Target - Figure 3-5


The maximum number of MIPI CSI-2 interfaces which can be connected to a single HP IO (UltraScale) or XPIO (Versal ACAP) bank depends on the number of clock capable pins available on that bank.

Figure 3-6: Subsystem Customization Screen - Pin Assignment

X-Ref Target - Figure 3-6