For soc chip power calculations one procedure is that use any power tool (ex: prime power) for calculation of power OR theritical method as follows. vendor will supply the power values for the MACROs , for memory macros we have comupte the power by using the following formula power P= (((read current +write current)/2 )*voltage *frequency, and coming for standard cells take equaualent nand gate power multiply with gate count then u can get the standard cell power. Finally by adding all these powers u can get avarage power value.