-----Original Message----- From: Andrew Warren To: PICLIST@MITVMA.MIT.EDU Date: Wednesday, 12 November 1997 16:07 Subject: Re: Microchip sues Scenix and parallax Tjaart van der Walt wrote: > You should see the patents that Mchip hold. Brownout, Power-up timer > etc. I think this is probably what Mchip is sueing for. You're correct, Tjaart... The six patents referenced in the suit are: 5473758: System having input output pins shifting between programming mode and normal mode to program memory without dedicating input output pins for programming mode AFAIK, Motorola 68705's do this. 5606511: Microcontroller with brownout detection 5454114: Microcontroller power-up delay 5033025: On-chip register setting and clearing 5469557: Code protection in microcontroller with EEPROM fuses Is this unique? What does the fuse material matter? (other than being the same as the main code memory) 5446864: System and method for protecting contents of microcontroller memory by providing scrambled data in response to an unauthorized read access without alteration of the memory contents > I just hope that whatever Scenix did to get 100Mips out of a flash > chip, is protected by the same patent system that prevents Scenix > from using on-chip brownout protection. A search of IBM's patent server (whose database is current as of 4 November 1997) shows NO patents EVER assigned to Scenix Semiconductor, Inc. They could be using non-patentable methods, and prefer trade secrets stuff to cover them. MikeS