I have been working with the GPIO as inputs for some time and have had some
success with this (GPIO 0,2,8-11,13-15 function as input). I would like to
use some of these pins as output and have not had success through either
manual configuration or using the CSL config functions. Most of the pins
sit high although a few are low (1,3). None alter state when using
pinWrite() or Write().
>Problem is now solved. It was that the HPI is multiplexed with the GPIO
>and at reset one specific pin (H14) must be pulled down via an external
From an old post I think that both the non-functioning inputs and no
outputs may be related to HPI multiplexing on the GPIO pins. I found some
suggestions that say there is a pin that must be tied low, although from
the documentation I found it seems Pin14 on the C6713 HPI Expansion
connector is HD2/AFSX1. I don't see any described as HPI enable as one
post suggested. I would appreciate it if someone has any suggestions or
could steer me towards a more detailed datasheet on the HPI/GPIO. I have
not found anything about HPI enabling in the ones with CCS (SPRU584,578).