checking two input pin states in assembly

ionymous

I am coding in assembly.
I have two input pins I am interested in, lets say pin 5 and 6.
The other inputs are in unknown states... I have not tied them to ground, and many are for peripherals since I'm using a development board.

I'm using "and" to mask the inputs I care about, and then "xor" with "wz" to determine if the bits I care about are set.

Here's an example:

                        mov     temp1, ina              'Get the current inputs
                        and     temp1, bothInputs       'Mask the inputs I care about

                        xor     temp1, bothInputs wz,nr 'Check if both inputs are high
        if_z            jmp     #BothInputsAreHigh             

                        xor     temp1, justInput5 wz,nr 'Check if just input 5 is high
        if_z            jmp     #JustInput5IsHigh             

        
bothInputs long %110_0000
justInput5 long %010_0000
temp1 long 0

Is this a good way to do it, or is there a better way?
Thanks
Ion

Ariba

You can use TEST, this is the same as AND with NR:

                 test    bothInputs,ina    wz,wc   'Mask the inputs I care about
  if_z           jmp     #BothInputsAreLow             
  if_nz_and_nc   jmp     #BothInputsAreHigh        'Carry is cleared if an even number of bits is set           
  if_nz_and_c    jmp     #OneInputsIsHigh          'Carry is set if an odd number of bits is set   

                 test    justInput5,ina    wz      'Check if just input 5 is high
  if_nz          jmp     #JustInput5IsHigh             
  if_z           jmp     #Input5IsLow             

' for waiting until inputs are set:
                 waitpeq bothInputs,bothInputs     'Wait until both are set
                 waitpne bothInputs,bothInputs     'Wait until one or both are cleared

The test for both inputs by the Carry works only with 2 inputs, if you have more bits, then your methode with xor is the right one.
And be aware that:
test maskreg,ina is not the same as test ina,maskreg
the second does not work as expected, because the INA has to be the source register.

Andy