Then we have do divide 1 usec /11 and generate output on the base of 64MHz clock.Could you predict what the accuracy should be for 11 MHz output.
you could work it out

@64 mHz the pic executes 1 instruction every 62.5 nano seconds
to toggle a pin @11 mHz thats twice every 91 nano seconds , you don't have even 1 inst period to work with

accuracy approx 0%

i can't work it out in my head but CCP is unlikely to get there either,

your going to need a bigger boat