Added more micro-operations, entire Montgomery exponentiation ladder works now.

1 files changed, 7 insertions, 3 deletions

diff --git a/rtl/modexpng_mmm_dual.v b/rtl/modexpng_mmm_dual.v
index 14f1b47..6e52a97 100644
--- a/rtl/modexpng_mmm_dual.v
+++ b/rtl/modexpng_mmm_dual.v
@@ -8,6 +8,7 @@ module modexpng_mmm_dual
     word_index_last,
     word_index_last_minus1,
     force_unity_b,
+    only_reduce,
     
     sel_wide_in, sel_narrow_in,
     
@@ -72,6 +73,7 @@ module modexpng_mmm_dual
     input [7:0] word_index_last;
     input [7:0] word_index_last_minus1;
     input       force_unity_b;
+    input only_reduce;
         
     input [BANK_ADDR_W-1:0] sel_wide_in;
     input [BANK_ADDR_W-1:0] sel_narrow_in;
@@ -120,7 +122,8 @@ module modexpng_mmm_dual
     //
     reg [FSM_STATE_WIDTH-1:0] fsm_state = FSM_STATE_IDLE;
     reg [FSM_STATE_WIDTH-1:0] fsm_state_next;
-    
+
+    wire [FSM_STATE_WIDTH-1:0] fsm_state_after_idle;    
     wire [FSM_STATE_WIDTH-1:0] fsm_state_after_mult_square;
     wire [FSM_STATE_WIDTH-1:0] fsm_state_after_mult_triangle;
     wire [FSM_STATE_WIDTH-1:0] fsm_state_after_mult_rectangle;
@@ -905,16 +908,17 @@ module modexpng_mmm_dual
     //
     // FSM Transition Logic
     //
+    assign fsm_state_after_idle = !only_reduce ? FSM_STATE_MULT_SQUARE_COL_0_INIT : FSM_STATE_MULT_TRIANGLE_COL_0_INIT;
     assign fsm_state_after_mult_square    = col_is_last ? FSM_STATE_MULT_SQUARE_HOLDOFF   : FSM_STATE_MULT_SQUARE_COL_N_INIT;
     assign fsm_state_after_mult_triangle  = col_is_last ? FSM_STATE_MULT_TRIANGLE_HOLDOFF : FSM_STATE_MULT_TRIANGLE_COL_N_INIT;
-    assign fsm_state_after_mult_rectangle = col_is_last ? FSM_STATE_MULT_RECTANGLE_HOLDOFF : FSM_STATE_MULT_RECTANGLE_COL_N_INIT;
+    assign fsm_state_after_mult_rectangle = col_is_last ? FSM_STATE_MULT_RECTANGLE_HOLDOFF : FSM_STATE_MULT_RECTANGLE_COL_N_INIT; 
 
     always @* begin
         //
         fsm_state_next = FSM_STATE_IDLE;
         //
         case (fsm_state)
-            FSM_STATE_IDLE:                   fsm_state_next = ena                   ? FSM_STATE_MULT_SQUARE_COL_0_INIT : FSM_STATE_IDLE;
+            FSM_STATE_IDLE:                   fsm_state_next = ena                   ? fsm_state_after_idle /*FSM_STATE_MULT_SQUARE_COL_0_INIT*/ : FSM_STATE_IDLE;
                         
             FSM_STATE_MULT_SQUARE_COL_0_INIT: fsm_state_next =                         FSM_STATE_MULT_SQUARE_COL_0_TRIG ;
             FSM_STATE_MULT_SQUARE_COL_0_TRIG: fsm_state_next =                         FSM_STATE_MULT_SQUARE_COL_0_BUSY ;