Column 17 lines 11-37 from 5809336 addresses the fundamental philosphy of two independent clocks.

"Most microprocessors derive all system timing from a single clock. The disadvantage is that different parts of the system can slow all operations. The microprocessor 50 provides a dual-clock scheme as shown in FIG. 17, with the 15 CPU 70 operating a synchronously to I/O interface 432 forming part of memory controller 118 (FIG. 2) and the I/O interface 432 operating synchronously with the external world of memory and I/O devices. The CPU 70 executes at the fastest speed possible using the adaptive ring counter 20 clock 430. Speed may vary by a factor of four depending upon temperature, voltage, and process. The external world must be synchronized to the microprocessor 50 for operations such as video display updating and disc drive reading and writing. This synchronization is performed by the I/O 25 interface 432, speed of which is controlled by a conventional crystal clock 434. The interface 432 processes requests for memory accesses from the microprocessor 50 and acknowledges the presence of I/O data. The microprocessor 50 fetches up to four instructions in a single memory cycle and 30 can perform much useful work before requiring another memory access. By decoupling the variable speed of the CPU 70 from the fixed speed of the I/O interface 432, optimum performance can be achieved by each. Recoupling between the CPU 70 and the interface 432 is accomplished 35 with handshake signals on lines 436, with data/addresses passing on bus 90, 136."

Why the examiner thinks that a variable speed clock and a fixed speed clock are obvious from the two clocks in the Kato design which are dependent on each other and therefore cannot be variable and fixed at the same time, is beyond me. The patent clearly states that one clock is variable and the other is fixed and therefore the term "independent" means more than being physically located in two separate locations. The 336 is clearly not obvious from kato/ledzius. The question now is what can be done to make the claims valid again and how long will it take. If the aproach taken for the 584 is succesful then I can only imagine that the wording on the claims will change further.