Serial-bus interface for multi-die module
Circuits and methods for efficient interconnect layout of multiple circuit elements, including integrated circuits (ICs), within a circuit module, while enabling only a single control/status (C/S) connection per module. In a first embodiment, the C/S interfaces of multiple ICs are configured in parallel within a multi-IC module, and coupled through a single module serial bus to a system C/S serial bus. In a second embodiment, the C/S interface of a primary IC is coupled through a single module serial bus to a system C/S serial bus, while a secondary IC is internally serially coupled to a “pass through” interface of the primary IC. In a third embodiment, a dynamic address translation circuit translates device and register address information provided by a master device into corresponding internal addresses, and re-directs command messages from a system C/S serial bus to internal slave devices.
1. A circuit module for housing a plurality of integrated circuits (ICs) while presenting a single unique address to a system control/status serial bus, including:
(a) an internal module serial bus configured to be coupled to the system control/status serial bus;
(b) a primary IC having at least one addressable control register and a control/status interface coupled to the internal module serial bus; and
(c) at least one secondary IC, each having at least one addressable control register and a control/status interface coupled to the internal module serial bus in parallel with the control/status interface of the primary IC;
wherein the primary IC and each secondary IC respond to control commands received through the internal module serial bus from the system control/status serial bus that correspond to a unique addressable control register within the primary IC or the secondary IC, and wherein only the primary IC responds to status requests received through the internal module serial bus from the system control/status serial bus, and each secondary IC is configured to not respond to status requests.
2. The invention of claim 1 , wherein the primary IC includes a set of duplicate addressable control registers corresponding to addressable control registers in at least one secondary IC, and wherein the primary IC responds to status requests received through the internal module serial bus from the system control/status serial bus and directed to an addressable control register of at least one secondary IC.
3. A method for connecting a circuit module in a housing for a plurality of integrated circuits (ICs) while presenting a single unique address to a system control/status serial bus, including:
(a) providing an internal module serial bus configured to be coupled to the system control/status serial bus;
(b) coupling a primary IC having at least one addressable control register and a control/status interface to the internal module serial bus;
(c) coupling at least one secondary IC, each having at least one addressable control register and a control/status interface to the internal module serial bus in parallel with the control/status interface of the primary IC;
(d) within the primary IC and each secondary IC, responding to control commands received through the internal module serial bus from the system control/status serial bus that correspond to a unique addressable control register within the primary IC or the secondary IC;
(e) within only the primary IC, responding to status requests received through the internal module serial bus from the system control/status serial bus; and
(f) within each secondary IC, not responding to status requests.
4. The method of claim 3 , wherein the primary IC includes a set of duplicate addressable control registers corresponding to addressable control registers in at least one secondary IC, and further including, within the primary IC, responding to status requests received through the internal module serial bus from the system control/status serial bus and directed to an addressable control register of at least one secondary IC.