As I understand it, which could be totally wrong. ARM intervened in the case mainly because of the 584. When the claim against the J”s was dropped from the case ARM was more or less disqualified as an intervener.

 "The 'instruction groups' elements of the accused claim of US Patent 5,784,584 (US '584) is deemed non-infringed for the purpose of this trial, based on the Court's claim interpretation, thereby allowing appeal from this claim interpretation ruling to be initiated immediately, rather than waiting until the end of trial. All accused ARM core families (ARM7, ARM9, ARM9E, ARM10E, ARM11), as well as the ARM Cortex microprocessor core family, are deemed non-infringed under the Court's claim interpretation of 'instruction groups,' thereby removing ARM as an intervener in the Texas Court trial."

This allowed TPL to apply pressure on the J’s and move towards trial with the 336 and the 148 without ARM’s assistance. So we were in a law suit with ARM by proxy. This may have been something TPL had not planned on. The point is each and every time the 548 patent comes up at trial as it pertains to ARM cores (and it will) ARM will intervene. WHY?

ARM's license agreements with its licensees often include provisions
which, subject to the satisfaction of certain conditions, require ARM to
indemnify its licensees if the licensed technology infringes the intellectual
property rights of a third party. The following proceedings, in which products
incorporating ARM's processor designs have been accused of patent infringement,
are subject to such indemnification provisions.

I have to agree we should not go after ARM just yet. A slow bleed by going after their customers first. Since ARM is the big guy on the block a license for them should cost a small fortune. Maybe after a couple of years ARM will be ripe for a hostile takeover. It was probably beneficial for them to intervene in the case; I think that next time TPL will be better prepared to defend the 548. I would like to hear an expert opinion of our situation with ARM. It’s hard to believe that we can expect such things out of our little company

  STMicroelectronics Inc. accused Motorola, Inc. (STMicroelectronics, Inc
v Motorola, Inc. United States District Court, Eastern District of Texas,
Sherman Division, Civil Action No. 4:03CV276) of infringing several of its
patents. Motorola counterclaimed with allegations that STMicroelectronics, Inc.
and STMicroelectronics N.V. infringe several Motorola patents, including
Motorola's U.S. Patent No. 5,084,814 (the "814 Patent"). Motorola alleges that
products based on ARM's processor designs infringe the 814 Patent. The Markman
hearing has taken place and the ruling of the District Court is awaited. ARM has been closely
involved in the defense of this litigation to the extent that it concerns the
814 Patent and is confident that the subject technology does not infringe the
814 patent. There is a limitation on ARM's liability under the indemnity
provision relating to this litigation of US$3,000,000, which has been provided
for in full.

Matsushita Electric Industrial Co., Ltd., accused Samsung Semiconductor,
Inc. (Matsushita Electric Industrial Co., Ltd v Samsung Electronics Co., Ltd et
al (Civil Action No. 02-CV-336) of infringing several of its patents. Samsung
counterclaimed with allegations that Matsushita infringes several Samsung
patents, including Samsung's U.S. Patent No. 5,781,750 (the "750 Patent") and
U.S. Patent No. 6,076,155 (the "155 Patent"). Samsung alleges that products
based on ARM's processor designs infringe the 750 Patent and the 155 Patent. The
litigation is currently in discovery. ARM is confident that the subject
technology does not infringe the 750 Patent or the 155 Patent. There is a
limitation on ARM's liability under the indemnity provision relating to this
litigation of US$1,500,000.