Opinion ID: 4150049
Heading Depth: 2
Heading Rank: 2

Heading: The Magar Reference

Text: Magar is a 1985 patent assigned to Texas Instruments that discloses a basic microprocessor. The Magar chip contains a clock generator (CLOCK GEN) located on the same silicon substrate as the remainder of the processor. The inputs of CLOCK GEN are pins X1 and X2, which are connected to a crystal or some other external generator. CLOCK GEN uses the signal from the external crystal to generate four clocks, Q1–Q4, that drive the chip. CLOCK GEN also regulates the chip’s timing or synchronization with external components with the CLKOUT pin. This is illustrated in Figure 2a: J.A. 2044. During prosecution, the examiner rejected what would become claim 6 of the ’336 patent under 35 U.S.C. § 103 in light of Magar. The patentee responded that 8 TECH. PROPS. LTD. v. HUAWEI TECHS. CO., LTD. Magar did not disclose the “entire oscillator” limitation and sought to traverse the rejection. In doing so, it made several statements the district court found to be disclaiming. First, the district court found that the patentee “attempted to distinguish Magar by emphasizing that the clock disclosed in Magar was fixed by a crystal that was external to the microprocessor, unlike their on-chip variable speed clock.” J.A. 9 (citing the following statement from the prosecution history). [O]ne of ordinary skill in the art should readily recognize that the speed of the cpu [sic] and the clock do not vary together due to manufacturing variation, operating voltage and temperature of the [integrated circuit] in the Magar microprocessor, as taught in the above quotation from the ref- erence. This is simply because the Magar microprocessor clock is frequency controlled by a crystal which is also external to the microprocessor. Crystals are by design fixed-frequency devices whose oscillation speed is designed to be tightly controlled and to vary minimally due to variations in manufacturing, operating voltage and temperature. The Magar microprocessor in no way con- templates a variable speed clock as claimed. J.A. 2092–93. Next, the district court stated that “the applicants also argued that the Magar clock could not practice the claimed invention because of its reliance on a crystal, which by its nature cannot vary its oscillator frequency.” J.A. 9 (citing the following statement from the prosecution history). [C]rystal oscillators have never, to Applicant’s knowledge, been fabricated on a single silicon substrate with a CPU, for instance. Even if they were, as previously mentioned, crystals are by design fixed-frequency devices whose oscillation frequency is designed to be tightly controlled and to TECH. PROPS. LTD. v. HUAWEI TECHS. CO., LTD. 9 vary minimally due to variations in manufactur- ing, operating voltage and temperature. The os- cillation frequency of a crystal on the same substrate with the microprocessor would inherently not vary due to variations in manufacturing, operating voltage and temperature in the same way as the frequency capability of the micropro- cessor on the same underlying substrate, as claimed. J.A. 2093. Third, the district court held that “[t]he applicants also disclaimed the use of an external crystal to cause clock signal oscillation.” J.A. 10 (citing the following statement from the prosecution history). Magar’s clock generator relies on an external crystal connected to terminals X1 and X2 to oscillate, as is conventional in microprocessor designs. It is not an entire oscillator in itself. And with the crystal, the clock rate generated is also conven- tional in that it is at a fixed, not a variable, fre- quency. The Magar clock is comparable in operation to the conventional crystal clock 434 depicted in Fig. 17 of the present application for controlling the I/O interface at a fixed rate frequency, and not at all like the clock on which the claims are based, as has been previously stated. J.A. 2101. Based on these statements, the district court concluded that “the applicants surrendered any oscillator that like Magar’s is fixed by an off-chip crystal” and held that the construction of “entire oscillator” must include the limitation “whose frequency is not fixed by any external crystal.” J.A. 7, 15.