Rambus Inc.
STACKED DEVICE COMMUNICATION

Abstract:

An interconnected stack of one or more Dynamic Random Access Memory (DRAM) die has a base logic die and one or more custom logic or processor die. The processor logic die snoops commands sent to and through the stack. In particular, the processor logic die may snoop mode setting commands (e.g., mode register set--MRS commands). At least one mode setting command that is ignored by the DRAM in the stack is used to communicate a command to the processor logic die. In response the processor logic die may prevent commands, addresses, and data from reaching the DRAM die(s). This enables the processor logic die to send commands/addresses and communicate data with the DRAM die(s). While being able to send commands/addresses and communicate data with the DRAM die(s), the processor logic die may execute software using the DRAM die(s) for program and/or data storage and retrieval.