An apparatus including a base layer of a platform application specific integrated circuit (ASIC), a mixed-signal function and a built-in self test (BIST) function. The base layer of the platform ASIC generally includes a plurality of pre-diffused regions disposed around a periphery of the platform ASIC. Each of the pre-diffused regions is generally configured to be metal-programmable. The mixed-signal function may include two or more sub-functions formed with a metal mask set placed over a first number of the plurality of pre-diffused regions. The BIST function may be formed with a metal mask set placed over a second number of the plurality of pre-diffused regions. The BIST function may be configured to test the mixed-signal function and present a digital signal indicating an operating condition of the mixed-signal function.