Asynchronous arbitration across clock domains for register writes in an integrated circuit chip

Abstract

A buffer chip includes a first interface to receive in-band register access commands from a host and a second interface to receive side-band register access commands from the host. The buffer chip further includes an arbitration circuit coupled to the first interface and to the second interface, wherein the arbitration circuit is to receive control signals from the first interface indicating a first pending register access command for the first interface, and wherein the arbitration circuit is to select the first pending register access command from concurrent pending register access commands from the first interface and the second interface using the control signals. In addition, the buffer chip includes a command buffer register coupled to the arbitration circuit, wherein the arbitration circuit to perform, on the command buffer register, a register access operation corresponding to the first pending register access command.