Just a few days ago Judge Whyte issued his Markman ruling for the Ware patents U.S. Patent No. 6,496,897 and 6,493,789, which are the subject of yet another Rambus lawsuit against Hynix and DRAM gang. At first glance the order appears unequivocally in favor of Rambus, but there are a few wrinkles that will likely yield yet another barrage of paperwork in these patent holy wars.
First while he rejected the DRAM maker’s arguments, and was favorably disposed to Rambus’ logic, the Judge decided that there was not a whole lot of distinction between the write enable (WE) signals and the mask bit term as argued by Rambus:
To begin, Rambus's construction of "mask bit" is synonymous with the specification's definition of "WE bit" or "WE signal." Rambus argues that a mask bit is a "binary digit indicating whether to write data," while in the specification, Rambus noted that a WE signal "indicates whether an associated byte is to be written or not during a write operation." See, e.g., Claim Construction Hrg. Tr. 377:3-378:15 (Jun. 5, 2008) (Mr. Detre urging that a "mask bit" and "write enable signal" are synonymous).
Because of this fact he went on to rule:
Nonetheless, the court cannot adopt Rambus's construction as proposed because it remains ambiguous. By defining a "mask bit" as a "binary digit indicating whether to write data," the construction blurs two distinct concepts. On the one hand, a DRAM receives a bit of information indicating whether an operation will be a read or a write operation. See '789 patent, col. 2, ll. 4-6. The Ware specification refers to this signal as a "W/R signal." Id. On the other hand, a DRAM can also receive a bit of information during a write operation indicating whether a particular piece of data should be written or not. The court's understanding of the specification and the claims indicate that Rambus's claims embrace the latter, but not the former. Nonetheless, Rambus's proposed construction of "mask bit" – "a binary digit indicating whether to write data" – could be misconstrued in the context of these claims to cover a "W/R signal" as well as the specification's "WE signal." Accordingly, the court opts to modify slightly Rambus's proposed construction. A "mask bit" is simply a "binary digit indicating whether to mask data involved in a write operation." This construction clarifies that the "mask" in "mask bit" refers to the action of masking data, and not the structure of a mask of data. It may also prevent future confusion about the scope of Rambus's claims.
You have to love Judges who reject both parties’ arguments for a claim, and then go on to say that this should “…prevent confusion.” Speaking from experience, it is hard to imagine a more confusing scenario than the Judge picking a brand new interpretation that then requires a whole new set of claim contentions, infringement evidence, etc..
What is intriguing about his analysis is that is truer to the specification, but slightly changes the nuance of the term. In Rambus’ request, they wanted the bit to be a bit indicating whether to write data. In his order he now says the bit indicates whether to mask data. Semantically and operationally they may turn out to be the same, and I have not studied it enough to decide who should win. But given the nature of these lawsuits I suspect this twist has given more wiggle room to the memory makers and I predict we will see many more filings arguing about this new definition very shortly.
Second, the Judge decided there was not enough information presented by the parties to help him decide who should win on the language calling for a first mask bit to be received "during a first half of a clock cycle of the external clock signal" and a second mask bit "during a second half of a clock cycle of the external clock signal." In his discussion he seemed to be leaning towards the DRAM makers, but he has asked for supplemental briefing by August 10. The final resolution of this issue is also critical before there is any clear understanding of the infringement positions. If the MM win on this point, there is no infringement. If they lose, I suspect we will see the bulk of the fight on the new “mask bit” variant offered by the Judge.
Finally the Judge indicated he was going to issue his ruling on the DRAM maker’s invalidity arguments for written description. Given his determination for the “mask bit” language, I suspect he is going to shoot down this request.
In the end, even if Rambus wins on the new claim points as well I suspect the main result will be a reexamination of the Ware patents also in due course.