         Name: LATFIR2.ASM
         Type: Assembler Macro
      Version: 1.0
  Last Change:  8-Aug-86

  Description: Lattice FIR Filter Assembler Macro

 This macro implements a lattice fir filter using reflection coefficients.
 This implementation is similar to the filter LATFIR1 except that the
 modulo on the coefficients is equal to the filter order compared to
 LATFIR1 where the modulo is equal to the filter order plus one.

 It is possible to modify the LATFIR1 slightly  such  that the
 number   of   locations   needed  to  store  the  filter coefficients
 is equal to the  number  of  filter  coefficients (note in  the
 implementation of LATFIR1 there is an unused value).
 The filter macro is identical to the filter macro 'latfir1'
 except for the last instruction.  The pointers  R0
 and  R4  are both adjusted by using dummy loads.  The memory map is
 thus:

       R0                 R4
       |                  |
       v                  v
   x:  S1 S2 S3 Sx     y: k1 k2 k3

        M0=3 (mod 4)       M4=2 (mod 3)

 The modulo register for the coefficients is set equal  to  the
 number  of  filter coefficients minus one (the modulo register
 is set to the desired modulo minus one).  See the example
 'latfir2t' in the DSPLIB for an example of how to use this filter.
