roblems with port configured as input

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cross mob
Anonymous
Not applicable

I am trying to do something with an Encore V MCU (7C64343). The problem I am facing has been described many times yet I have been unable to make it work for me at this stage:
On port 1 I have a few digital inputs and one output controlled by an interrupt function.
My problem is that I can never read the actual status of the inputs, they are always 0.
What I am doing is this:

   

The relevant bits P1.2, P1.3 and P1.4 are configured as StdCPUInput and drive Analog High Z in the PD

unsigned char P1;

and then in the interrupt function (executed around 100 times per second):

P1=PRT1DR; // supposedly reads the actual input states
P1^=0x20; // swinging the output pin
PRT1DR=P1; // update the output

Everywhere else in the code I only use P1 as read from the code above.
Where is my problem here?

Thanks!

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