i am giving you an general idea about it.
SOP=describe the process to assure that standard coding activities,which produce TLG's are conducted in accordance with industry standards are appropriately documented.
SAP=it contained detailed information about what statistical methods to be used to produce T L G's.
Protocol=it is the detailed document that has every detail about trial like method used,
references,statistical method to be use(summary),study design..
i hope it will help you.