The PEL Interface

• call dmm( maskno )

  Return RC_OK if any bit in that mask is on. For example:-

    call dmm(2)
    call anl
  

  If any bit on the DARN bank 2 mask is set, proceed to ANL otherwise quit event.

• call dmm( maskno, bitmask )

  Return RC_OK if any of bits set in bitmask is set for the mask For example:-

    call dmm(0,7)
    if_ok quit_event
  

  If any of bits 0, 1 or 2 of the DAMN bank 0 is set quit event. (Recall in PEL the default action after failure of a processor is to quit, but this action is suppressed if the next command is a conditional as it is in this case).

• call dmm( maskno, bitmask, mode )

  Perform the operation defined by mode on mask maskno using the bits selected in bitmask.

    mode   = action*100 + value
  
    action =  0 OR  test of selected bits against value
           =  1 AND test of selected bits against value
           =  2 SET selected bits to value
  
    value  =  0 0 (false)
           =  1 1 (true)
           =  2   (undefined)
           = 10 not 0 (not allowed for SET)
           = 11 not 1 ( "    "      "   " )
           = 12 not 2 ( "    "      "   " )
  
  Examples:-
  
    call dmm(0,12,111) Return RC_OK if bits 2 and 3 of DAMN bank 0 
                       are both not 1 (either 0 or undefined).
    call dmm(3,5,201)  Set bits 0 and 2 of DARN 3 mask to 1.
  

  When DMM is used to set bits it always returns RC_OK. In principle tests of arbitrary complexity can be built up with multiple DMM calls although it is better to deal with these be defining a filter, see below.