Simplified index calculation and accumulator clearing logic.

Better debug printout of accumulators.

1 files changed, 16 insertions, 13 deletions

diff --git a/modexpng_fpga_model.py b/modexpng_fpga_model.py
index d3b7841..844cc86 100644
--- a/modexpng_fpga_model.py
+++ b/modexpng_fpga_model.py
@@ -353,13 +353,22 @@ class ModExpNG_WordMultiplier():
 
         for col in range(num_cols):
 
-            self._clear_all_macs()
-            self._preset_indices(col)
+            for t in range(ab_num_words):
 
-            if dump and DUMP_MACS_CLEARING:
-                print("t= 0, col=%2d > clear > all" % (col))
+                if t == 0: self._preset_indices(col)    
+                else:      self._rotate_indices(ab_num_words)
+
+                if t == 0:
+                    self._clear_all_macs()
+                    if dump and DUMP_MACS_CLEARING:
+                        print("t= 0, col=%2d > clear > all" % (col))
+                else:
+                    t1 = t - 1
+                    if (t1 // 8) == col:
+                        self._clear_one_mac(t1 % NUM_MULTS)
+                        if dump and DUMP_MACS_CLEARING:
+                            print("t=%2d, col=%2d > clear > x=%d:" % (t, col, t1 % NUM_MULTS))
 
-            for t in range(ab_num_words):
 
                 if dump and DUMP_INDICES:
                     print("t=%2d, col=%2d > indices:" % (t, col), end='')
@@ -377,18 +386,14 @@ class ModExpNG_WordMultiplier():
 
                     if t == (col * NUM_MULTS + x):
                         parts[t] = self._macs[x]
-                        self._clear_one_mac(x)
-                        if dump and DUMP_MACS_CLEARING:
-                            print("t=%2d, col=%2d > clear > x=%d:" % (t, col, x))
 
                 if dump and DUMP_MACS_ACCUMULATION:
+                    print("t=%2d, col=%2d > "% (t, col), end='')
                     for i in range(NUM_MULTS):
                         if i > 0: print(" | ", end='')
-                        print("[%d]: 0x%012x" % (i, self._macs[i]), end='')
+                        print("mac[%d]: 0x%012x" % (i, self._macs[i]), end='')
                     print("")
 
-
-
                 # save the uppers part of product at end of column,
                 # for the last column don't save the very last part
                 if t == (ab_num_words - 1):
@@ -396,8 +401,6 @@ class ModExpNG_WordMultiplier():
                         if not (col == (num_cols - 1) and x == (NUM_MULTS - 1)):
                             parts[ab_num_words + col * NUM_MULTS + x] = self._macs[x]
 
-                self._rotate_indices(ab_num_words)
-
         return parts
 
     def multiply_triangle(self, a_wide, b_narrow, ab_num_words):