RSHIFT on Nano-10 +r73

[garysdickinson]

Is it a know problem with Nano-10 +r73 that the RSHIFT command does not function as documented on actual hardware?

If I initialize DM[] as follows:
DM[1] = &H8000
DM[2] = &H8000
DM[3] = &H8000
DM[4] = &H8000

Then issue:
RSHIFT DM[1],4       ' shift one bit right DM[1..4]

This is what I see:

DM[1] = &HC000
DM[2] = &HC000
DM[3] = &HC000
DM[4] = &HC000

This is what I expected:
DM[1] = &H4000
DM[2] = &H4000
DM[3] = &H4000
DM[4] = &H4000


I am not seeing the least significant bit being shifted into the most significant bit of the lower numbered variable.

What I am seeing is a shift within each 16 bit register that is mostly a propagation of the signed bit.  

For RSHIFT to be useful it CAN NOT be a 16-bit unsigned shift.

In the simulator the RSHIFT command executes as documented.

If I purchase a new Nano-10 is this problem resolved?

Gary D

[support]

Firmware version >= r78 corrected a bug in the RSHIFT command and that the new firmware should work as expected. In fact r78 now supports RSHIFT and LSHIFT of 32 bit variables (including DM[32]) across boundary so you can RSHIFT DM32[1],2  and it will shift correctly as it treats DM[1] & DM[2] as DM32[1] and DM[3] & DM[4] as DM32[2].

[garysdickinson]

Thanks,

I am using a work-around for the firmware problem:
 

   ' This code is a work-around for the firmware problem.
   '
   ' The following code is equivalent to this statement:
   '   RSHIFT DM[1],4
   '
   for j = 1 to 3             ' worry about carry in for first 3 registers
      RSHIFT DM[j],1      
      if testbit(DM[j+1],0)
         setbit DM[j],15      ' Carry-in will be a 1
      else
         clrbit DM[j],15      ' Carry-in will be a 0
      endif
   next
   RSHIFT DM[j],1            ' No carry into most significant register

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This will keep me working until I get new hardware,

Gary D.