Route CSI_D*P/N pairs with controlled 100-Ω, differential impedance (±20%) or 50-Ω, single-ended impedance (±15%).
Keep away from other high-speed signals.
Keep intra-pair length mismatch to < 5 mils.
Keep inter-pair length mismatch to < 50 mils within a single CSI-2 TX port. CSI-2 TX Port 0 differential traces do not need to match CSI-2 Port 1 differential traces.
Have length matching near the location of mismatch.
Separate each pair by at least by 3 times the signal trace width.
Keep the use of bends in differential traces to a minimum. When bends are used, the number of left and right bends must be as equal as possible, and the angle of the bend should be ≥ 135 degrees. This arrangement minimizes any length mismatch caused by the bends, and therefore minimizes the impact that bends have on EMI.
Route all differential pairs on the same layer.
Keep the number of VIAS to a minimum — TI recommends keeping the VIA count to 2 or fewer.
Keep traces on layers adjacent to ground plane.
Do NOT route differential pairs over any plane split.
Place all test points in series and symmetrically, if used. Test points must not be placed in a manner that causes a stub on the differential pair. Remember the adding test points can cause impedance discontinuity, and therefore can negatively impact signal performance.