Follow up HW#13

 suggestions

- Add a short note on how CL1 and CL2 set the load capacitance the crystal sees: CL = (CL1*CL2)/(CL1+CL2) + Cstray. With 22 pF caps this lands near the common 12 to 18 pF crystal spec once stray is included, and stating it explicitly ties your part choices to the datasheet.

pierceCalc

Consider analysis of heatmap

trace, 3d, heat map＊ heat map by me, trace route and 3D by Mr. Su