I have made a data acquisition cape for my BeagleBone that digitizes analog signals and receives 10 MHz and 1PPS timing inputs. The 1PPS input is wired to the TIMER4 pin and is intended to be captured by timer4 on the rising edge. I have enabled this pin to mode 2, Rx enabled, and enabled capture on rising edge. However, the pin is being driven as an output by the processor, so my input signal is not getting into the timer.
Section 20.2.1.4 of the AM3359 TRM has a semi-useful description of PORGPOCFG bit, but fails to say whether it should be 0 or 1 for capture input mode. It also implies that it's an output bit.
A schematic diagram of the timer I/O pin wiring with mode control bit values called out would be very helpful at this time. Short of that, what bits must be set to what values to get the TIMER4 pin's capture input to work?