The PMC and LPD MIOs have similar functionality. There are 52 routing channels in the PMC and 26 channels in the LPD. The control registers for the input and output multiplexers are in two separate register sets.
If an I/O signal from a peripheral is not selected by the MIO_PIN routing register, then it usually is available on the EMIO interface to the PL.
The multiplexing for outputs include several cascading levels. The level 3 multiplexing is used for low-speed signals. The level 0 multiplexing is used for high-speed signals and many of the clocks.
Note: The first routing decision for the LPD I/O signals is between the LPD and PMC multiplexers. This functionality is not shown in the following figure.
Figure 1. MIO Channel Diagram