The Software IP Report

“Protocol Module” Deemed Indefinite for Lack of Structure

The District Court for the Northern District of California recently handed down a claim construction order in Microchip Technology Incorporated v. Nuvoton Technology that held the claim limitation “protocol module” was indefinite under 35 U.S.C. § 112, ¶2.  Both parties agreed that the term “protocol module” was subject to interpretation under 35 U.S.C. § 112, ¶6 (means-plus-function).  However, the defendant argued that the specification did not disclose any structure for performing the claimed function “providing configuration data for one of two or more serial communication protocols based on the protocol selection.” 

Claim 1, which was deemed representative, recited:

A system comprising:

an interface module including a buffer or register for storing a protocol selection;

a protocol module coupled to the interface module and configured for providing configuration data for one of two or more serial communication protocols based on the protocol selection;

a serial engine module coupled to the interface module and the protocol module, the serial engine module configured for:

          determining from the protocol selection that data or commands are to be transmitted and received on a serial communication bus using synchronous communication;

          determining that a port control module coupled to the serial communication bus is configured for asynchronous communication on the serial communication bus;

          reconfiguring the port control module from asynchronous serial communication to synchronous serial communication on the serial communication bus, including selecting one of an internal or an external clock signal for synchronous communication on the serial communication bus; and

          transmitting and receiving data or commands over the serial communication bus synchronously using the clock signal.

The Patent Owner proposed that the corresponding structure disclosed in the specification was “a lookup table of configuration settings.”  However, the court focused on whether the specification sufficiently disclosed how the “protocol module” could “provid[e] configuration data for one of two or more serial communication.”   As discussed in Williamson v. Citrix Online, LLC, 792 F.3d 1339 (Fed. Cir. 2015), “structure disclosed in the specification qualifies as ‘corresponding structure’ if the intrinsic evidence clearly links or associates that structure to the function recited in the claim.” 

The court agreed with the Patent Owner that the specification disclosed how the protocol module receives protocol settings and selects one of the protocol selection settings.  For example, the relevant portion of the specification (including Figure 2, which is reproduced below) stated that the “protocol module 220 may include one or more protocol configuration settings 224” and the “protocol module 220 may be coupled to the interface module 210 and may receive a protocol setting from the interface module.  Based on the received protocol setting, one of the protocol  configurations of the protocol module 220 may be selected.”

However, the court found the specification failed to link any structure disclosed in the specification to the functionality “providing configuration data for one of two or more serial communication protocols based on the protocol selection.” 

Lessons for Practice

Unfortunately, it does not appear that the specification included mention of a lookup table, which appears to be what the “protocol module” is (or at least one implementation of the protocol module).  For example, the specification also recites that “The protocol module 220 may include one or more protocol configuration settings 224. As an example, the protocol module 220 may include the configuration settings 224 for the I2C, SMBus, SPI, and USART serial communication protocols” as well as “Based on the received signal, a protocol is selected (320). As an example the protocol module 220 may receive the selected serial communication protocol from the control and status registers 212 and based on the received selection may select one of the protocol configuration settings 224.” 

If the specification included mention of a lookup table, the Patent Owner may have been able to argue that the specification included a link between the corresponding structure “lookup table” and the recited functionality “providing configuration data for one of two or more serial communication protocols based on the protocol selection.” 

Thus, patent practitioners may want to incorporate clear and unequivocal examples of potential structures within the specification if they want to use the terms “module” in the claims.