In the Rev1 version of the T1040 Reference manual, the GPIO block got a new register - The "GPIO Input Buffer Enable Register (GPIOx_GPIBE)". This was not in the older RevE manual. The manual says this:
The GPIO Input Buffer Enable register is used to control the input enable of each
individual GPIO port. When an individual GPIO port’s direction is set to input
(GPIO_GPDIR[DRn=0]), the associated input enable must be set (GPIOxGPIE[IEn]=1)
to propagate the port value to the GPIO Data Register. When a port’s input enable is
disabled, the port value does not propagate to the GPIO Data Register.
What CPU version was this implemented in? And what happens if I don't set them. The documentation says that a value of zero makes the port disabled, and the reset value for the register is all zero's, meaning all inputs are disabled.
We are building a new CPU board that uses the T1042 cpu, and I'm confused about what happens here. I am working off the T1040RDB, but it doesn't actually use any GPIO so it doesn't help me.
The latest UBoot software does not have this register in their register mapping headers.