Ultra low current pulse generator (for BLE module interrupt)
You don't say which pin you mean when you say "EN pin", I assume it is simply one of the I/O pins. For the CC2541, you can determine in software whether any pin has a pull-up or not. By default they have pull-up, but you can remove that by setting the correct bit in the PxINP register.

The CC2541 also has plenty of internal timers that can be used to pull-up/down one of the I/O pins, so you don't need an external timer.