1) Should each power supply pin connect with one 100nF decouple capacitor?
2) Due to small package, I can not place one capacitor for each power supply pin. Can the power supply pin of nearby share one 100nF capacitor as below?
Please check this link. https://www.intel.com/content/www/us/en/programmable/support/support-resources/support-centers/board-design-guidelines.html?elq_cid=7421858_ts1638791698283&erpm_id=9987570_ts1638791698283
You can use PDN tool for the target device or use the PDN Decoupling Calculator Tool (link available on above webpage).