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

A method comprising:

• receiving, by a command buffer coupled to one or more volatile memory devices, in-band register access commands from a host via a first interface;
• receiving, by the command buffer, side-band register access commands from the host via a second interface;
• arbitrating, by the command buffer, between the in-band register access commands and the side-band register access commands received via the first and second interfaces;
• and
• performing, by the command buffer on a command buffer register, register access operations corresponding to the in-band register access commands and the side-band register access commands.

A memory module comprising:

• one or more volatile memory devices;
• a command buffer coupled to the one or more volatile memory devices, the command buffer comprising:
• a first interface to receive in-band register access commands from a host;
• a second interface to receive side-band register access commands from the host;
• an arbitration circuit coupled to the first interface and to the second interface, wherein the arbitration circuit is to arbitrate between the in-band register access commands and the side-band register access commands received via the first and second interfaces;
• and
• 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 in-band register access commands and the side-band register access commands.