Multiple chip package processor having feed through paths on one die

Abstract

An architecture for a serial multi-chip package digital controller including a controller oriented processor die and a separate non-volatile memory die. The architecture provides for a low pin count on the package, minimal electrical connections on and between the dice, and a minimal number of registers by making use of significant multiplexing to allow many of the registers and signal lines to serve multiple functions responsive to the mode of operation and other control signals. A plurality of feed-throughs are provided on the non-volatile memory die to provide communication paths from the processor die to package pads which are in the shadow of the non-volatile memory die relative to the processor die and thus prevent direct connection from the processor die to the package pad. In normal run mode, these pads are exclusively used as feed-through, providing a direct connection between a specific pad on the processor die and a specific pad on the package. In other modes of operation, however, the signals input from (or output to) the feed-through package pads are re-routed by transfer gates to the non-volatile memory die.