This can be done fairly easily and with a wide variety of resources. The PWM can be connected to output row 2 for example, then use two adjacent output interconnects 2 and 1. Use output row 1 interconnect and turn on all ouput drivers and select input B (row 2) use the output interconnect Row 2 and turn on all output drivers. You will now have 8 Global output columns with the same PWM signal. These can now be hooked up to 8 output pins using Ports 0 and 1 (four from each port).
Alternately you could use only four global output columns and use 2 pins from 4 ports to accomplish the same thing or by selecting only even numbered ports, you can get by with only using 4 global outputs. Here is an example of the last.
The LEDs can then be turned on and off by external signals from the other end of the LED or by software turning off the output driver.
