Redesigned core architecture, unified bank structure. All storage blocks now

have eight 4kbit entries and occupy one 36K BRAM tile.

1 files changed, 1225 insertions, 0 deletions

diff --git a/rtl/_modexpng_recombinator_block.v b/rtl/_modexpng_recombinator_block.v
new file mode 100644
index 0000000..61bf734
--- /dev/null
+++ b/rtl/_modexpng_recombinator_block.v
@@ -0,0 +1,1225 @@
+module modexpng_recombinator_block
+(
+    clk, rst,
+    ena, rdy,
+    mmm_fsm_state_next,
+    word_index_last,
+    dsp_xy_ce_p,
+    dsp_x_p, dsp_y_p,
+    col_index, col_index_last,
+    rd_narrow_xy_addr, rd_narrow_xy_bank,
+    rcmb_wide_xy_bank,   rcmb_wide_xy_addr,   rcmb_wide_x_dout,   rcmb_wide_y_dout,   rcmb_wide_xy_valid,
+    rcmb_narrow_xy_bank, rcmb_narrow_xy_addr, rcmb_narrow_x_dout, rcmb_narrow_y_dout, rcmb_narrow_xy_valid,
+    rdct_narrow_xy_bank, rdct_narrow_xy_addr, rdct_narrow_x_dout, rdct_narrow_y_dout, rdct_narrow_xy_valid
+);
+
+
+    //
+    // Headers
+    //
+    `include "../rtl/modexpng_parameters.vh"
+    `include "../rtl/modexpng_mmm_fsm.vh"
+
+
+    input                                         clk;
+    input                                         rst;
+    input                                         ena;
+    output                                        rdy;
+    input  [                MMM_FSM_STATE_W -1:0] mmm_fsm_state_next;
+    input  [                OP_ADDR_W       -1:0] word_index_last;
+    input                                         dsp_xy_ce_p;
+    input  [(NUM_MULTS+1) * MAC_W           -1:0] dsp_x_p;
+    input  [(NUM_MULTS+1) * MAC_W           -1:0] dsp_y_p;
+    input  [                COL_INDEX_W     -1:0] col_index;
+    input  [                COL_INDEX_W     -1:0] col_index_last;
+    
+    input  [                BANK_ADDR_W     -1:0] rd_narrow_xy_bank;
+    input  [                OP_ADDR_W       -1:0] rd_narrow_xy_addr;
+
+    output [                BANK_ADDR_W     -1:0] rcmb_wide_xy_bank;
+    output [                OP_ADDR_W       -1:0] rcmb_wide_xy_addr;
+    output [                WORD_EXT_W      -1:0] rcmb_wide_x_dout;
+    output [                WORD_EXT_W      -1:0] rcmb_wide_y_dout;
+    output                                        rcmb_wide_xy_valid;
+
+    output [                BANK_ADDR_W     -1:0] rcmb_narrow_xy_bank;
+    output [                OP_ADDR_W       -1:0] rcmb_narrow_xy_addr;
+    output [                WORD_EXT_W      -1:0] rcmb_narrow_x_dout;
+    output [                WORD_EXT_W      -1:0] rcmb_narrow_y_dout;
+    output                                        rcmb_narrow_xy_valid;
+
+    output [                BANK_ADDR_W     -1:0] rdct_narrow_xy_bank;
+    output [                OP_ADDR_W       -1:0] rdct_narrow_xy_addr;
+    output [                WORD_EXT_W      -1:0] rdct_narrow_x_dout;
+    output [                WORD_EXT_W      -1:0] rdct_narrow_y_dout;
+    output                                        rdct_narrow_xy_valid;
+
+
+    //
+    // Latches
+    //
+    reg [MAC_W-1:0] dsp_x_p_latch[0:NUM_MULTS];
+    reg [MAC_W-1:0] dsp_y_p_latch[0:NUM_MULTS];
+
+
+    //
+    // Mapping
+    //
+    wire [MAC_W-1:0] dsp_x_p_split[0:NUM_MULTS];
+    wire [MAC_W-1:0] dsp_y_p_split[0:NUM_MULTS];
+    
+    genvar z;
+    generate for (z=0; z<NUM_MULTS_AUX; z=z+1)
+        begin : gen_dsp_xy_p_split
+            assign dsp_x_p_split[z] = dsp_x_p[z*MAC_W +: MAC_W];
+            assign dsp_y_p_split[z] = dsp_y_p[z*MAC_W +: MAC_W];
+        end
+    endgenerate
+
+
+    //
+    // Delays
+    //
+    reg dsp_xy_ce_p_dly1 = 1'b0;
+
+    always @(posedge clk)
+        //
+        if (rst) dsp_xy_ce_p_dly1 <= 1'b0;
+        else     dsp_xy_ce_p_dly1 <= dsp_xy_ce_p;
+
+
+    //
+    // Registers
+    //
+    
+    // valid
+    reg       xy_valid_lsb = 1'b0;
+    reg       xy_aux_lsb   = 1'b0;
+    reg       xy_valid_msb = 1'b0;
+    
+    // bitmap
+    reg [NUM_MULTS-1:0] xy_bitmap_lsb = {NUM_MULTS{1'b0}};
+    reg [NUM_MULTS-1:0] xy_bitmap_msb = {NUM_MULTS{1'b0}};
+    
+    // index
+    reg [2:0] xy_index_lsb = 3'dX;
+    
+    // purge
+    reg       xy_purge_lsb = 1'b0;
+    reg       xy_purge_msb = 1'b0;
+    
+    // valid - latch
+    reg       xy_valid_latch_lsb = 1'b0;
+    
+    // aux - latch
+    reg       xy_aux_latch_lsb = 1'b0;
+    
+    // bitmap - latch
+    reg [NUM_MULTS-1:0] xy_bitmap_latch_lsb = MULT_BITMAP_ZEROES;
+    reg [NUM_MULTS-1:0] xy_bitmap_latch_msb = MULT_BITMAP_ZEROES;
+
+    // index - latch
+    reg [MAC_INDEX_W-1:0] xy_index_latch_lsb = MAC_INDEX_DONT_CARE;
+    
+    // purge - index
+    reg       xy_purge_latch_lsb = 1'b0;
+    reg       xy_purge_latch_msb = 1'b0;
+
+    // 
+    reg       xy_valid_lsb_adv[1:6];
+    reg       xy_valid_msb_adv[1:6];
+    reg       xy_aux_lsb_adv[1:6];
+    reg [NUM_MULTS-1:0] xy_bitmap_lsb_adv[1:6];
+    reg [NUM_MULTS-1:0] xy_bitmap_msb_adv[1:6];
+    reg [MAC_INDEX_W-1:0] xy_index_lsb_adv[1:6];
+    reg [MAC_INDEX_W-1:0] xy_index_msb_adv[1:6];
+    reg       xy_purge_lsb_adv[1:6];
+    reg       xy_purge_msb_adv[1:6];
+    
+    reg [1:0] rcmb_mode;
+       
+    always @(posedge clk)
+       //
+       if (ena)
+           //
+           case (mmm_fsm_state_next)
+               MMM_FSM_STATE_MULT_SQUARE_COL_0_BUSY:        rcmb_mode <= 2'd1;
+               MMM_FSM_STATE_MULT_TRIANGLE_COL_0_BUSY:      rcmb_mode <= 2'd2;
+               MMM_FSM_STATE_MULT_RECTANGLE_COL_0_BUSY:     rcmb_mode <= 2'd3;
+               default:                                 rcmb_mode <= 2'd0;
+           endcase
+
+               
+    integer i;
+    initial for (i=1; i<6; i=i+1) begin
+        xy_valid_lsb_adv[i] = 1'b0;
+        xy_valid_msb_adv[i] = 1'b0;
+        xy_aux_lsb_adv[i] = 1'b0;
+        xy_bitmap_lsb_adv[i] = {8{1'b0}};
+        xy_bitmap_msb_adv[i] = {8{1'b0}};
+        xy_index_lsb_adv[i] = 3'dX;
+        xy_index_msb_adv[i] = 3'dX;
+        xy_purge_lsb_adv[i] = 1'b0;
+        xy_purge_msb_adv[i] = 1'b0;
+    end
+    
+    function        calc_square_triangle_valid_lsb;
+        //
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [  OP_ADDR_W-1:0] narrow_xy_addr_value;
+        begin
+            //
+            if (narrow_xy_addr_value[7:3] == col_index_value)
+                calc_square_triangle_valid_lsb = 1'b1;
+            else
+                calc_square_triangle_valid_lsb = 1'b0;
+            //
+        end
+    endfunction
+
+    function                    calc_square_valid_lsb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [  OP_ADDR_W-1:0] narrow_xy_addr_value;
+        begin
+            calc_square_valid_lsb = calc_square_triangle_valid_lsb(col_index_value, col_index_last_value, narrow_xy_bank_value, narrow_xy_addr_value);   
+        end
+    endfunction
+
+    function        calc_triangle_valid_lsb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        begin
+            calc_triangle_valid_lsb = calc_square_triangle_valid_lsb(col_index_value, col_index_last_value, narrow_xy_bank_value, narrow_xy_addr_value);   
+        end
+    endfunction
+    
+    function        calc_rectangle_valid_lsb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        begin
+            //
+            if (narrow_xy_addr_value[7:3] == col_index_value) 
+                calc_rectangle_valid_lsb = narrow_xy_bank_value != BANK_NARROW_EXT;
+            else
+                calc_rectangle_valid_lsb = 1'b0;
+            //
+        end
+    endfunction
+
+    function        calc_triangle_aux_lsb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        begin
+            //
+            if (narrow_xy_bank_value == BANK_NARROW_EXT)
+                calc_triangle_aux_lsb = 1'b1;
+            else
+                calc_triangle_aux_lsb = 1'b0;
+            //
+        end
+    endfunction
+    
+    function  [7:0] calc_square_triangle_bitmap_lsb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        begin
+            //
+            if (narrow_xy_addr_value[7:3] == col_index_value)
+                //
+                case (narrow_xy_addr_value[2:0])
+                    3'b000: calc_square_triangle_bitmap_lsb = 8'b00000001;
+                    3'b001: calc_square_triangle_bitmap_lsb = 8'b00000010;
+                    3'b010: calc_square_triangle_bitmap_lsb = 8'b00000100;
+                    3'b011: calc_square_triangle_bitmap_lsb = 8'b00001000;
+                    3'b100: calc_square_triangle_bitmap_lsb = 8'b00010000;
+                    3'b101: calc_square_triangle_bitmap_lsb = 8'b00100000;
+                    3'b110: calc_square_triangle_bitmap_lsb = 8'b01000000;
+                    3'b111: calc_square_triangle_bitmap_lsb = 8'b10000000;
+                endcase
+                //
+            else
+                calc_square_triangle_bitmap_lsb = {8{1'b0}};
+            //
+        end
+    endfunction
+
+    function  [7:0] calc_square_bitmap_lsb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        begin
+            calc_square_bitmap_lsb = calc_square_triangle_bitmap_lsb(col_index_value, col_index_last_value, narrow_xy_bank_value, narrow_xy_addr_value);
+        end
+    endfunction
+
+    function  [7:0] calc_triangle_bitmap_lsb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        begin
+            calc_triangle_bitmap_lsb = calc_square_triangle_bitmap_lsb(col_index_value, col_index_last_value, narrow_xy_bank_value, narrow_xy_addr_value);
+        end
+    endfunction
+
+    function  [7:0] calc_rectangle_bitmap_lsb;
+       input [COL_INDEX_W-1:0] col_index_value;
+       input [COL_INDEX_W-1:0] col_index_last_value;
+       input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+       input [7:0] narrow_xy_addr_value;
+       begin
+           //
+           if ((narrow_xy_addr_value[7:3] == col_index_value) && (narrow_xy_bank_value != BANK_NARROW_EXT))
+               //
+               case (narrow_xy_addr_value[2:0])
+                   3'b000: calc_rectangle_bitmap_lsb = 8'b00000001;
+                   3'b001: calc_rectangle_bitmap_lsb = 8'b00000010;
+                   3'b010: calc_rectangle_bitmap_lsb = 8'b00000100;
+                   3'b011: calc_rectangle_bitmap_lsb = 8'b00001000;
+                   3'b100: calc_rectangle_bitmap_lsb = 8'b00010000;
+                   3'b101: calc_rectangle_bitmap_lsb = 8'b00100000;
+                   3'b110: calc_rectangle_bitmap_lsb = 8'b01000000;
+                   3'b111: calc_rectangle_bitmap_lsb = 8'b10000000;
+               endcase
+               //
+           else
+               calc_rectangle_bitmap_lsb = {8{1'b0}};
+           //
+        end
+    endfunction
+       
+       /*
+        * These can be simplified (the difference between square/triangle and
+        * rectangle is that the bank is checked or not). A universal function would
+        * accept a parameter that tells it whether it should check the bank or not.
+        * Let's do it later, too early to optimize now, it seems.
+        *
+        *
+        */
+       
+    function  [2:0] calc_square_triangle_index_lsb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        begin
+            //
+            if (narrow_xy_addr_value[7:3] == col_index_value)
+                //
+                case (narrow_xy_addr_value[2:0])
+                    3'b000: calc_square_triangle_index_lsb = 3'd0;
+                    3'b001: calc_square_triangle_index_lsb = 3'd1;
+                    3'b010: calc_square_triangle_index_lsb = 3'd2;
+                    3'b011: calc_square_triangle_index_lsb = 3'd3;
+                    3'b100: calc_square_triangle_index_lsb = 3'd4;
+                    3'b101: calc_square_triangle_index_lsb = 3'd5;
+                    3'b110: calc_square_triangle_index_lsb = 3'd6;
+                    3'b111: calc_square_triangle_index_lsb = 3'd7;
+                endcase
+                //
+            else
+                calc_square_triangle_index_lsb = 3'dX;
+            //
+        end
+    endfunction
+
+    function  [2:0] calc_square_index_lsb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        begin
+            calc_square_index_lsb = calc_square_triangle_index_lsb(col_index_value, col_index_last_value, narrow_xy_bank_value, narrow_xy_addr_value);
+        end
+    endfunction
+
+    function  [2:0] calc_triangle_index_lsb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        begin
+            calc_triangle_index_lsb = calc_square_triangle_index_lsb(col_index_value, col_index_last_value, narrow_xy_bank_value, narrow_xy_addr_value);
+        end
+    endfunction
+
+    function  [2:0] calc_rectangle_index_lsb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] slim_bram_xy_bank_value;
+        input [7:0] slim_bram_xy_addr_value;
+        begin
+            //
+            if ((slim_bram_xy_addr_value[7:3] == col_index_value) && (slim_bram_xy_bank_value != BANK_NARROW_EXT))
+                //
+                case (slim_bram_xy_addr_value[2:0])
+                    3'b000: calc_rectangle_index_lsb = 3'd0;
+                    3'b001: calc_rectangle_index_lsb = 3'd1;
+                    3'b010: calc_rectangle_index_lsb = 3'd2;
+                    3'b011: calc_rectangle_index_lsb = 3'd3;
+                    3'b100: calc_rectangle_index_lsb = 3'd4;
+                    3'b101: calc_rectangle_index_lsb = 3'd5;
+                    3'b110: calc_rectangle_index_lsb = 3'd6;
+                    3'b111: calc_rectangle_index_lsb = 3'd7;
+                endcase
+                //
+            else
+                calc_rectangle_index_lsb = 3'dX;
+            //
+        end
+    endfunction
+    
+    function        calc_square_rectangle_purge_lsb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        begin
+            //
+            if (narrow_xy_addr_value[7:3] == col_index_value)
+                calc_square_rectangle_purge_lsb = narrow_xy_addr_value[7:3] == col_index_last_value;
+            else
+                calc_square_rectangle_purge_lsb = 1'b0;
+            //
+        end
+    endfunction
+
+    function        calc_square_purge_lsb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        begin
+            calc_square_purge_lsb = calc_square_rectangle_purge_lsb(col_index_value, col_index_last_value, narrow_xy_bank_value, narrow_xy_addr_value);
+        end
+    endfunction
+
+    function        calc_rectangle_purge_lsb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        begin
+            calc_rectangle_purge_lsb = calc_square_rectangle_purge_lsb(col_index_value, col_index_last_value, narrow_xy_bank_value, narrow_xy_addr_value);
+        end
+    endfunction
+
+    function        calc_square_valid_msb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        input [7:0] index_last_value;
+        begin
+            //
+            if (narrow_xy_addr_value == index_last_value)
+                calc_square_valid_msb = 1'b1;
+            else
+                calc_square_valid_msb = 1'b0;
+            //
+        end
+    endfunction
+
+    function        calc_rectangle_valid_msb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        input [7:0] index_last_value;
+        begin
+            //
+            if ((narrow_xy_addr_value == 8'd1) && (narrow_xy_bank_value == BANK_NARROW_EXT))
+                calc_rectangle_valid_msb = 1'b1;
+            else
+                calc_rectangle_valid_msb = 1'b0;
+            //
+        end
+    endfunction
+    
+    function  [7:0] calc_square_bitmap_msb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        input [7:0] index_last_value;
+        begin
+            //
+            if (narrow_xy_addr_value == index_last_value) begin
+                calc_square_bitmap_msb[7] = col_index_value != col_index_last_value;
+                calc_square_bitmap_msb[6:0] = 7'b1111111;
+            end else
+                calc_square_bitmap_msb[7:0] = 8'b00000000;
+            //
+        end
+    endfunction
+
+    function  [7:0] calc_rectangle_bitmap_msb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        input [7:0] index_last_value;
+        begin
+            //
+            if ((narrow_xy_addr_value == 8'd1) && (narrow_xy_bank_value == BANK_NARROW_EXT)) begin
+                calc_rectangle_bitmap_msb[7:0] = 8'b11111111;
+            end else
+                calc_rectangle_bitmap_msb[7:0] = 8'b00000000;
+            //
+        end
+    endfunction
+
+    function        calc_square_purge_msb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        input [7:0] index_last_value;
+        begin
+            //
+            if (narrow_xy_addr_value == index_last_value)
+                calc_square_purge_msb = col_index_value == col_index_last_value;
+            else
+                calc_square_purge_msb = 1'b0;
+            //
+        end
+    endfunction
+
+    function        calc_rectangle_purge_msb;
+        input [COL_INDEX_W-1:0] col_index_value;
+        input [COL_INDEX_W-1:0] col_index_last_value;
+        input [BANK_ADDR_W-1:0] narrow_xy_bank_value;
+        input [7:0] narrow_xy_addr_value;
+        input [7:0] index_last_value;
+        begin
+            //
+            if ((narrow_xy_addr_value == 8'd1) && (narrow_xy_bank_value == BANK_NARROW_EXT))
+                calc_rectangle_purge_msb = col_index_value == col_index_last_value;
+            else
+                calc_rectangle_purge_msb = 1'b0;
+            //
+        end
+    endfunction
+
+    
+    reg         rcmb_xy_lsb_ce = 1'b0;
+    reg         rcmb_xy_lsb_ce_aux;
+    reg  [ 2:0] rcmb_xy_lsb_ce_purge = 3'b000;
+    wire        rcmb_xy_lsb_ce_combined = rcmb_xy_lsb_ce | rcmb_xy_lsb_ce_aux | rcmb_xy_lsb_ce_purge[0];
+    reg         rcmb_xy_lsb_clr;
+
+    reg  [46:0] rcmb_x_lsb_din;
+    reg  [46:0] rcmb_y_lsb_din;
+    wire [15:0] rcmb_x_lsb_dout;
+    wire [15:0] rcmb_y_lsb_dout;
+
+    reg         rcmb_xy_msb_ce = 1'b0;
+    reg  [ 1:0] rcmb_xy_msb_ce_purge = 2'b00;
+    wire        rcmb_xy_msb_ce_combined = rcmb_xy_msb_ce | rcmb_xy_msb_ce_purge[0];
+    reg         rcmb_xy_msb_clr;
+    
+    reg  [46:0] rcmb_x_msb_din;
+    reg  [46:0] rcmb_y_msb_din;
+    wire [15:0] rcmb_x_msb_dout;
+    wire [15:0] rcmb_y_msb_dout;
+    
+    modexpng_recombinator_cell recomb_x_lsb
+    (
+        .clk    (clk),
+        .ce     (rcmb_xy_lsb_ce_combined),
+        .clr    (rcmb_xy_lsb_clr),
+        .din    (rcmb_x_lsb_din),
+        .dout   (rcmb_x_lsb_dout)
+    );
+    modexpng_recombinator_cell recomb_y_lsb
+    (
+        .clk    (clk),
+        .ce     (rcmb_xy_lsb_ce_combined),
+        .clr    (rcmb_xy_lsb_clr),
+        .din    (rcmb_y_lsb_din),
+        .dout   (rcmb_y_lsb_dout)
+    );
+
+    modexpng_recombinator_cell recomb_x_msb
+    (
+        .clk    (clk),
+        .ce     (rcmb_xy_msb_ce_combined),
+        .clr    (rcmb_xy_msb_clr),
+        .din    (rcmb_x_msb_din),
+        .dout   (rcmb_x_msb_dout)
+    );
+    
+    modexpng_recombinator_cell recomb_y_msb
+    (
+        .clk    (clk),
+        .ce     (rcmb_xy_msb_ce_combined),
+        .clr    (rcmb_xy_msb_clr),
+        .din    (rcmb_y_msb_din),
+        .dout   (rcmb_y_msb_dout)
+    );
+
+    always @(posedge clk) begin
+        //
+        rcmb_xy_lsb_ce <= xy_valid_latch_lsb;
+        rcmb_xy_lsb_ce_aux <= xy_aux_latch_lsb;
+        rcmb_xy_msb_ce <= xy_bitmap_latch_msb[0];
+        //
+        if (xy_purge_latch_lsb)
+            rcmb_xy_lsb_ce_purge <= 3'b111;
+        else
+            rcmb_xy_lsb_ce_purge <= {1'b0, rcmb_xy_lsb_ce_purge[2:1]};
+        //
+        if (xy_purge_latch_msb && xy_bitmap_latch_msb[0] && !xy_bitmap_latch_msb[1])
+            rcmb_xy_msb_ce_purge = 2'b11;
+        else
+            rcmb_xy_msb_ce_purge <= {1'b0, rcmb_xy_msb_ce_purge[1]};
+        //
+    end
+
+
+    always @(posedge clk)
+        //
+        if (ena) begin
+            rcmb_xy_lsb_clr <= 1'b1;
+            rcmb_xy_msb_clr <= 1'b1;
+        end else begin
+            if (rcmb_xy_lsb_ce) rcmb_xy_lsb_clr <= 1'b0;
+            if (rcmb_xy_msb_ce) rcmb_xy_msb_clr <= 1'b0;
+        end
+
+    always @(posedge clk)
+        //
+        if (xy_valid_latch_lsb) begin
+            rcmb_x_lsb_din <= dsp_x_p_latch[xy_index_latch_lsb];
+            rcmb_y_lsb_din <= dsp_y_p_latch[xy_index_latch_lsb];
+        end else if (xy_aux_latch_lsb) begin
+            rcmb_x_lsb_din <= dsp_x_p_latch[8];
+            rcmb_y_lsb_din <= dsp_y_p_latch[8];
+        end else begin
+            rcmb_x_lsb_din <= {47{1'b0}};
+            rcmb_y_lsb_din <= {47{1'b0}};
+        end
+
+    always @(posedge clk)
+        //
+        if (xy_bitmap_latch_msb[0]) begin
+            rcmb_x_msb_din <= dsp_x_p_latch[0];
+            rcmb_y_msb_din <= dsp_y_p_latch[0];
+        end else begin
+            rcmb_x_msb_din <= {47{1'b0}};
+            rcmb_y_msb_din <= {47{1'b0}};
+        end
+
+
+    always @(posedge clk)
+        //
+        case (mmm_fsm_state_next)
+            //
+            MMM_FSM_STATE_MULT_SQUARE_COL_0_TRIG,
+            MMM_FSM_STATE_MULT_SQUARE_COL_N_TRIG,
+            MMM_FSM_STATE_MULT_SQUARE_COL_0_BUSY,
+            MMM_FSM_STATE_MULT_SQUARE_COL_N_BUSY: begin
+                //
+                xy_valid_lsb_adv [6] <= calc_square_valid_lsb (col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr);
+                xy_aux_lsb_adv   [6] <= 1'b0;
+                xy_bitmap_lsb_adv[6] <= calc_square_bitmap_lsb(col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr);
+                xy_index_lsb_adv [6] <= calc_square_index_lsb (col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr);
+                xy_purge_lsb_adv [6] <= calc_square_purge_lsb (col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr);
+                //
+                xy_valid_msb_adv [6] <= calc_square_valid_msb (col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr, word_index_last);
+                xy_bitmap_msb_adv[6] <= calc_square_bitmap_msb(col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr, word_index_last);
+                xy_purge_msb_adv [6] <= calc_square_purge_msb (col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr, word_index_last);
+                //
+            end
+            //
+            MMM_FSM_STATE_MULT_TRIANGLE_COL_0_TRIG,
+            MMM_FSM_STATE_MULT_TRIANGLE_COL_N_TRIG,
+            MMM_FSM_STATE_MULT_TRIANGLE_COL_0_BUSY,
+            MMM_FSM_STATE_MULT_TRIANGLE_COL_N_BUSY: begin
+                //
+                xy_valid_lsb_adv [6] <= calc_triangle_valid_lsb (col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr);
+                xy_aux_lsb_adv   [6] <= calc_triangle_aux_lsb   (col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr);
+                xy_bitmap_lsb_adv[6] <= calc_triangle_bitmap_lsb(col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr);
+                xy_index_lsb_adv [6] <= calc_triangle_index_lsb (col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr);
+                xy_purge_lsb_adv [6] <= 1'b0;
+                //
+                xy_valid_msb_adv [6] <= 1'b0;
+                xy_bitmap_msb_adv[6] <= {8{1'b0}};
+                xy_purge_msb_adv [6] <= 1'b0;
+                //
+            end
+            //
+            MMM_FSM_STATE_MULT_RECTANGLE_COL_0_TRIG,
+            MMM_FSM_STATE_MULT_RECTANGLE_COL_N_TRIG,
+            MMM_FSM_STATE_MULT_RECTANGLE_COL_0_BUSY,
+            MMM_FSM_STATE_MULT_RECTANGLE_COL_N_BUSY: begin
+                //
+                xy_valid_lsb_adv [6] <= calc_rectangle_valid_lsb (col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr);
+                xy_aux_lsb_adv   [6] <= 1'b0;
+                xy_bitmap_lsb_adv[6] <= calc_rectangle_bitmap_lsb(col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr);
+                xy_index_lsb_adv [6] <= calc_rectangle_index_lsb (col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr);
+                xy_purge_lsb_adv [6] <= calc_rectangle_purge_lsb (col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr);
+                //
+                xy_valid_msb_adv [6] <= calc_rectangle_valid_msb (col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr, word_index_last);
+                xy_bitmap_msb_adv[6] <= calc_rectangle_bitmap_msb(col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr, word_index_last);
+                xy_purge_msb_adv [6] <= calc_rectangle_purge_msb (col_index, col_index_last, rd_narrow_xy_bank, rd_narrow_xy_addr, word_index_last);
+                //
+            end
+            //
+            default: begin
+                //
+                xy_valid_lsb_adv [6] <= 1'b0;
+                xy_aux_lsb_adv   [6] <= 1'b0;
+                xy_bitmap_lsb_adv[6] <= {8{1'b0}};
+                xy_index_lsb_adv [6] <= 3'dX;
+                xy_purge_lsb_adv [6] <= 1'b0;
+                //
+                xy_valid_msb_adv [6] <= 1'b0;
+                xy_bitmap_msb_adv[6] <= {8{1'b0}};
+                xy_purge_msb_adv [6] <= 1'b0;
+                //
+            end
+            //
+        endcase
+
+
+    always @(posedge clk) begin
+        //
+        xy_valid_lsb  <= xy_valid_lsb_adv [1];
+        xy_aux_lsb    <= xy_aux_lsb_adv   [1];
+        xy_bitmap_lsb <= xy_bitmap_lsb_adv[1];
+        xy_index_lsb  <= xy_index_lsb_adv [1];
+        xy_purge_lsb  <= xy_purge_lsb_adv [1];
+        //
+        xy_valid_latch_lsb  <= xy_valid_lsb;
+        xy_aux_latch_lsb    <= xy_aux_lsb;
+        xy_bitmap_latch_lsb <= xy_bitmap_lsb;
+        xy_index_latch_lsb  <= xy_index_lsb;
+        xy_purge_latch_lsb  <= xy_purge_lsb;
+        //
+        xy_valid_msb  <= xy_valid_msb_adv[1];
+        xy_bitmap_msb <= xy_bitmap_msb_adv[1];
+        xy_purge_msb  <= xy_purge_msb_adv[1];
+        //
+        if (xy_valid_msb) begin
+            xy_bitmap_latch_msb <= xy_bitmap_msb;
+            xy_purge_latch_msb  <= xy_purge_msb;
+        end else begin
+            xy_bitmap_latch_msb <= {1'b0, xy_bitmap_latch_msb[7:1]};
+        end
+        //
+        //
+        for (i=1; i<6; i=i+1) begin
+            xy_valid_lsb_adv [i] <= xy_valid_lsb_adv [i+1];
+            xy_aux_lsb_adv   [i] <= xy_aux_lsb_adv   [i+1];
+            xy_bitmap_lsb_adv[i] <= xy_bitmap_lsb_adv[i+1];
+            xy_index_lsb_adv [i] <= xy_index_lsb_adv [i+1];
+            xy_purge_lsb_adv [i] <= xy_purge_lsb_adv [i+1];
+            //
+            xy_valid_msb_adv [i] <= xy_valid_msb_adv [i+1];
+            xy_bitmap_msb_adv[i] <= xy_bitmap_msb_adv[i+1];
+            xy_purge_msb_adv [i] <= xy_purge_msb_adv [i+1];
+        end
+        //
+    end
+
+    always @(posedge clk)
+        //
+        if (xy_bitmap_latch_msb[1])   // only shift 7 times
+            //
+            for (i=0; i<8; i=i+1)
+                //            
+                if (i < 7) begin
+                    dsp_x_p_latch[i] <= dsp_x_p_latch[i+1];
+                    dsp_y_p_latch[i] <= dsp_y_p_latch[i+1];
+                end else begin
+                    dsp_x_p_latch[i] <= {47{1'bX}};
+                    dsp_y_p_latch[i] <= {47{1'bX}};
+                end
+            //
+        else if (dsp_xy_ce_p_dly1) begin
+            //
+            for (i=0; i<8; i=i+1)
+                //
+                if (xy_bitmap_lsb[i]) begin
+                    dsp_x_p_latch[i] <= dsp_x_p_split[i];
+                    dsp_y_p_latch[i] <= dsp_y_p_split[i];
+                end else if (xy_valid_msb && xy_bitmap_msb[i]) begin
+                    dsp_x_p_latch[i] <= dsp_x_p_split[i];
+                    dsp_y_p_latch[i] <= dsp_y_p_split[i];
+                end
+            //
+            if (xy_aux_lsb) begin
+                dsp_x_p_latch[8] <= dsp_x_p_split[8];
+                dsp_y_p_latch[8] <= dsp_y_p_split[8];
+            end
+            //
+        end
+
+    reg rcmb_xy_lsb_valid = 1'b0;
+    reg rcmb_xy_msb_valid = 1'b0;
+
+    always @(posedge clk)
+        //
+        if (rst) begin
+            rcmb_xy_lsb_valid <= 1'b0;
+            rcmb_xy_msb_valid <= 1'b0;        
+        end else begin
+            rcmb_xy_lsb_valid <= rcmb_xy_lsb_ce_combined;
+            rcmb_xy_msb_valid <= rcmb_xy_msb_ce_combined;
+        end        
+
+
+    reg [BANK_ADDR_W-1:0] wide_xy_bank;
+    reg [ 7:0] wide_xy_addr;
+    reg [17:0] wide_x_dout;
+    reg [17:0] wide_y_dout;
+    reg        wide_xy_valid = 1'b0;
+
+    reg [BANK_ADDR_W-1:0] narrow_xy_bank;
+    reg [ 7:0] narrow_xy_addr;
+    reg [17:0] narrow_x_dout;
+    reg [17:0] narrow_y_dout;
+    reg        narrow_xy_valid = 1'b0;
+
+    reg [BANK_ADDR_W-1:0] rdct_xy_bank;
+    reg [ 7:0] rdct_xy_addr;
+    reg [17:0] rdct_x_dout;
+    reg [17:0] rdct_y_dout;
+    reg        rdct_xy_valid = 1'b0;
+
+    reg [ 7:0] cnt_lsb;
+    reg [ 7:0] cnt_msb;
+    
+    reg        cnt_lsb_wrapped;
+    reg        cnt_msb_wrapped;
+
+    reg [31:0] rcmb_xy_msb_carry_0;
+    reg [31:0] rcmb_xy_msb_carry_1;
+    
+    reg [31:0] rcmb_xy_msb_delay_0;
+    reg [31:0] rcmb_xy_msb_delay_1;
+    reg [31:0] rcmb_xy_msb_delay_2;
+    
+    reg [ 7:0] rcmb_msb_cnt_delay_0 = 8'd0;
+    reg [ 7:0] rcmb_msb_cnt_delay_1 = 8'd0;
+    reg [ 7:0] rcmb_msb_cnt_delay_2 = 8'd0;
+
+    reg        rcmb_msb_flag_delay_0;
+    reg        rcmb_msb_flag_delay_1;
+    reg        rcmb_msb_flag_delay_2;
+    
+    assign rcmb_wide_xy_bank  = wide_xy_bank;
+    assign rcmb_wide_xy_addr  = wide_xy_addr;
+    assign rcmb_wide_x_dout   = wide_x_dout;
+    assign rcmb_wide_y_dout   = wide_y_dout;
+    assign rcmb_wide_xy_valid = wide_xy_valid;
+
+    assign rcmb_narrow_xy_bank  = narrow_xy_bank;
+    assign rcmb_narrow_xy_addr  = narrow_xy_addr;
+    assign rcmb_narrow_x_dout   = narrow_x_dout;
+    assign rcmb_narrow_y_dout   = narrow_y_dout;
+    assign rcmb_narrow_xy_valid = narrow_xy_valid;
+
+    assign rdct_narrow_xy_bank  = rdct_xy_bank;
+    assign rdct_narrow_xy_addr  = rdct_xy_addr;
+    assign rdct_narrow_x_dout   = rdct_x_dout;
+    assign rdct_narrow_y_dout   = rdct_y_dout;
+    assign rdct_narrow_xy_valid = rdct_xy_valid;
+    
+    reg rdy_reg = 1'b1;
+    reg rdy_adv = 1'b1;
+    
+    assign rdy = rdy_reg;
+    
+    
+    always @(posedge clk)
+        //
+        if (ena) rdy_reg <= 1'b0;
+        else     rdy_reg <= rdy_adv;
+            
+    task advance_rcmb_msb_delay;
+        input [15:0] dout_x;
+        input [15:0] dout_y;
+        input [ 7:0] cnt;
+        input        flag;
+        begin
+            //
+            rcmb_xy_msb_delay_0 <= {dout_y, dout_x};
+            rcmb_xy_msb_delay_1 <= rcmb_xy_msb_delay_0;
+            rcmb_xy_msb_delay_2 <= rcmb_xy_msb_delay_1;
+            //
+            rcmb_msb_cnt_delay_0 <= cnt;
+            rcmb_msb_cnt_delay_1 <= rcmb_msb_cnt_delay_0;
+            rcmb_msb_cnt_delay_2 <= rcmb_msb_cnt_delay_1;
+            //
+            rcmb_msb_flag_delay_0 <= flag;
+            rcmb_msb_flag_delay_1 <= rcmb_msb_flag_delay_0;
+            rcmb_msb_flag_delay_2 <= rcmb_msb_flag_delay_1;
+            //
+        end
+    endtask
+         
+    task shift_rcmb_msb_carry;
+        input [15:0] dout_x;
+        input [15:0] dout_y;
+        begin
+            rcmb_xy_msb_carry_0 <= {dout_y, dout_x};
+            rcmb_xy_msb_carry_1 <= rcmb_xy_msb_carry_0;
+        end
+    endtask
+    
+    task _update_wide;
+        input [BANK_ADDR_W-1:0] bank;
+        input [ 7:0] addr;
+        input [17:0] dout_x;
+        input [17:0] dout_y;
+        input        valid;
+        begin
+            wide_xy_bank       <= bank;
+            wide_xy_addr       <= addr;
+            wide_x_dout        <= dout_x;
+            wide_y_dout        <= dout_y;
+            wide_xy_valid <= valid;
+        end
+    endtask
+    
+    task _update_narrow;
+        input [BANK_ADDR_W-1:0] bank;
+        input [ 7:0] addr;
+        input [17:0] dout_x;
+        input [17:0] dout_y;
+        input        valid;
+        begin
+            narrow_xy_bank       <= bank;
+            narrow_xy_addr       <= addr;
+            narrow_x_dout        <= dout_x;
+            narrow_y_dout        <= dout_y;
+            narrow_xy_valid <= valid;
+        end
+    endtask
+
+    task _update_rdct;
+        input [BANK_ADDR_W-1:0] bank;
+        input [ 7:0] addr;
+        input [17:0] dout_x;
+        input [17:0] dout_y;
+        input        valid;
+        begin
+            rdct_xy_bank       <= bank;
+            rdct_xy_addr       <= addr;
+            rdct_x_dout        <= dout_x;
+            rdct_y_dout        <= dout_y;
+            rdct_xy_valid <= valid;
+        end
+    endtask
+            
+    task set_wide;
+        input [BANK_ADDR_W-1:0] bank;
+        input [ 7:0] addr;
+        input [17:0] dout_x;
+        input [17:0] dout_y;
+        begin
+            _update_wide(bank, addr, dout_x, dout_y, 1'b1);
+        end
+    endtask
+    
+    task set_narrow;
+        input [BANK_ADDR_W-1:0] bank;
+        input [ 7:0] addr;
+        input [17:0] dout_x;
+        input [17:0] dout_y;
+        begin
+            _update_narrow(bank, addr, dout_x, dout_y, 1'b1);
+        end
+    endtask
+    
+    task set_rdct;
+        input [BANK_ADDR_W-1:0] bank;
+        input [ 7:0] addr;
+        input [17:0] dout_x;
+        input [17:0] dout_y;
+        begin
+            _update_rdct(bank, addr, dout_x, dout_y, 1'b1);
+        end
+    endtask
+    
+    task clear_wide;
+        begin
+            _update_wide(BANK_DONT_CARE, 8'hXX, {18{1'bX}}, {18{1'bX}}, 1'b0);
+        end
+    endtask
+
+    task clear_narrow;
+        begin
+            _update_narrow(BANK_DONT_CARE, 8'hXX, {18{1'bX}}, {18{1'bX}}, 1'b0);
+        end
+    endtask
+
+    task clear_rdct;
+        begin
+            _update_rdct(BANK_DONT_CARE, 8'hXX, {18{1'bX}}, {18{1'bX}}, 1'b0);
+        end
+    endtask
+    
+    task _set_cnt_lsb;
+        input [7:0] cnt;
+        input       wrapped;
+        begin
+            cnt_lsb <= cnt;
+            cnt_lsb_wrapped <= wrapped;
+        end
+    endtask
+    
+    task _set_cnt_msb;
+        input [7:0] cnt;
+        input       wrapped;
+        begin
+            cnt_msb <= cnt;
+            cnt_msb_wrapped <= wrapped;
+        end
+    endtask    
+
+    task inc_cnt_lsb;
+        begin
+            if (cnt_lsb == word_index_last)
+                _set_cnt_lsb(8'd0, 1'b1);
+            else
+                _set_cnt_lsb(cnt_lsb + 1'b1, cnt_lsb_wrapped);
+        end
+    endtask
+    
+    task inc_cnt_both;
+        begin
+            inc_cnt_lsb;
+            inc_cnt_msb;
+        end
+    endtask
+    
+    task inc_cnt_msb;
+        begin
+            if (cnt_msb == word_index_last)
+                _set_cnt_msb(8'd0, 1'b1);
+            else
+                _set_cnt_msb(cnt_msb + 1'b1, cnt_msb_wrapped);
+        end
+    endtask
+    
+    task clr_cnt_lsb;
+        begin
+            _set_cnt_lsb(8'd0, 1'b0);
+        end
+    endtask
+    
+    task clr_cnt_msb;
+        begin
+            _set_cnt_msb(8'd0, 1'b0);
+        end
+    endtask
+    
+   
+
+    wire [1:0] rcmb_xy_valid = {rcmb_xy_msb_valid, rcmb_xy_lsb_valid}; 
+    
+    always @(posedge clk)
+        //
+        if (ena) begin
+            clr_cnt_lsb();
+            clr_cnt_msb();
+        end else if (!rdy)
+            //
+            case (rcmb_mode)
+                2'd1: recombine_square();
+                2'd2: recombine_triangle();
+                2'd3: recombine_rectangle();
+            endcase
+           
+    wire [17:0] rcmb_x_lsb_dout_pad = {2'b00, rcmb_x_lsb_dout};
+    wire [17:0] rcmb_y_lsb_dout_pad = {2'b00, rcmb_y_lsb_dout};
+
+    wire [17:0] rcmb_x_msb_dout_pad = {2'b00, rcmb_x_msb_dout};
+    wire [17:0] rcmb_y_msb_dout_pad = {2'b00, rcmb_y_msb_dout};
+    
+    wire [17:0] rcmb_x_msb_delay_2_pad = {2'b00, rcmb_xy_msb_delay_2[15: 0]};
+    wire [17:0] rcmb_y_msb_delay_2_pad = {2'b00, rcmb_xy_msb_delay_2[31:16]};
+
+    wire [17:0] rcmb_x_lsb_msb_carry_1_pad = {1'b0, {1'b0, rcmb_x_lsb_dout} + {1'b0, rcmb_xy_msb_carry_1[15: 0]}};
+    wire [17:0] rcmb_y_lsb_msb_carry_1_pad = {1'b0, {1'b0, rcmb_y_lsb_dout} + {1'b0, rcmb_xy_msb_carry_1[31:16]}};
+           
+           
+    task recombine_square;
+        //
+        begin
+            //
+            case (rcmb_xy_valid)
+                //
+                2'b01: inc_cnt_lsb; 
+                2'b10: inc_cnt_msb;
+                2'b11: inc_cnt_both;
+                //
+            endcase            
+            //
+            case (rcmb_xy_valid)
+                //
+                2'b00: if (rcmb_msb_flag_delay_2) set_wide(BANK_WIDE_H, rcmb_msb_cnt_delay_2, rcmb_x_msb_delay_2_pad, rcmb_y_msb_delay_2_pad);
+                       else                       clear_wide;
+                //
+                2'b01:                            set_wide(BANK_WIDE_L, cnt_lsb, rcmb_x_lsb_dout_pad, rcmb_y_lsb_dout_pad);
+                //
+                2'b10: if (cnt_msb < 8'd2)        clear_wide;                        
+                       else                       set_wide(BANK_WIDE_H, cnt_msb, rcmb_x_msb_dout_pad, rcmb_y_msb_dout_pad);
+                //
+                2'b11: if (cnt_lsb_wrapped)       set_wide(BANK_WIDE_H, cnt_lsb, rcmb_x_lsb_msb_carry_1_pad, rcmb_y_lsb_msb_carry_1_pad); 
+                       else                       set_wide(BANK_WIDE_L, cnt_lsb, rcmb_x_lsb_dout_pad,        rcmb_y_lsb_dout_pad);
+                //
+            endcase            
+            //
+            case (rcmb_xy_valid)
+                //
+                2'b00: if (rcmb_msb_flag_delay_2) advance_rcmb_msb_delay(16'hXXXX, 16'hXXXX, 8'd0, 1'b0);
+                2'b10: if (cnt_msb < 8'd2)        shift_rcmb_msb_carry(rcmb_x_msb_dout, rcmb_y_msb_dout);
+                //
+                2'b11: begin                      advance_rcmb_msb_delay(rcmb_x_msb_dout, rcmb_y_msb_dout, cnt_msb, 1'b1);
+                       if (cnt_lsb_wrapped)       shift_rcmb_msb_carry({16{1'bX}}, {16{1'bX}});
+                       end
+                //
+            endcase
+            //        
+        end
+        //
+    endtask
+    
+    
+    task recombine_triangle;
+        //
+        begin
+            //
+            case (rcmb_xy_valid)
+                //
+                2'b01: inc_cnt_lsb(); 
+               //
+            endcase            
+            //
+            case (rcmb_xy_valid)
+                //
+                2'b00:                        clear_narrow;
+                2'b01:  if (!cnt_lsb_wrapped) set_narrow(BANK_NARROW_Q,   cnt_lsb, rcmb_x_lsb_dout_pad, rcmb_y_lsb_dout_pad); 
+                        else                  set_narrow(BANK_NARROW_EXT, 8'd1,    rcmb_x_lsb_dout_pad, rcmb_y_lsb_dout_pad);
+                2'b10:                        clear_narrow;
+                2'b11:                        clear_narrow;
+                //
+            endcase
+            //        
+        end
+        //
+    endtask
+
+
+    task recombine_rectangle;
+        //
+        begin
+            //
+            case (rcmb_xy_valid)
+                //
+                2'b01:  inc_cnt_lsb; 
+                2'b10:  inc_cnt_msb;
+                2'b11:  inc_cnt_both;
+                //
+            endcase
+//            //
+            case (rcmb_xy_valid)
+//                //
+                2'b00:  if (rcmb_msb_flag_delay_2)  set_rdct(BANK_RCMB_MH, rcmb_msb_cnt_delay_2, rcmb_x_msb_delay_2_pad, rcmb_y_msb_delay_2_pad);
+                        else                        clear_rdct;
+                2'b01:                              set_rdct(BANK_RCMB_ML, cnt_lsb, rcmb_x_lsb_dout_pad, rcmb_y_lsb_dout_pad); 
+                2'b10:  if (!cnt_msb_wrapped) begin 
+                            if (cnt_msb < 8'd2)     clear_rdct;                        
+                            else                    set_rdct(BANK_RCMB_MH, cnt_msb, rcmb_x_msb_dout_pad, rcmb_y_msb_dout_pad);
+                        end else                    set_rdct(BANK_RCMB_EXT, 8'd0, rcmb_x_msb_dout_pad, rcmb_y_msb_dout_pad);
+                            
+                2'b11:  set_rdct(BANK_RCMB_MH, cnt_lsb, rcmb_x_lsb_msb_carry_1_pad, rcmb_y_lsb_msb_carry_1_pad); 
+//                //
+            endcase            
+//            //
+            case (rcmb_xy_valid)
+//                //
+                2'b00:  if (rcmb_msb_flag_delay_2)  advance_rcmb_msb_delay(16'hXXXX, 16'hXXXX, 8'd0, 1'b0);
+                2'b10:  begin 
+                            if ((cnt_msb < 8'd2) && !cnt_msb_wrapped) shift_rcmb_msb_carry(rcmb_x_msb_dout, rcmb_y_msb_dout);
+                            if (cnt_msb_wrapped) advance_rcmb_msb_delay(16'hXXXX, 16'hXXXX, 8'd0, 1'b0);
+                        end
+//                //
+                2'b11:  begin  advance_rcmb_msb_delay(rcmb_x_msb_dout, rcmb_y_msb_dout, cnt_msb, 1'b1);
+                                   shift_rcmb_msb_carry({16{1'bX}}, {16{1'bX}});
+                        end
+//                //
+            endcase
+            //
+        end
+        //
+    endtask
+    
+    
+    always @(posedge clk)
+        //
+        if (ena) begin
+            rdy_adv <= 1'b0;
+        end else if (!rdy_reg) begin
+            //
+            case (rcmb_mode)
+                //
+                2'd1:   case (rcmb_xy_valid)
+                            //
+                            2'b00: begin
+                                //
+                                if (rcmb_msb_flag_delay_2) begin
+                                    //
+                                    rdy_adv <= ~rcmb_msb_flag_delay_1;
+                                    //
+                                end
+                                //
+                            end
+                            //
+                        endcase
+                //
+                2'd2:   case (rcmb_xy_valid)
+                            //
+                            2'b01: rdy_adv <= cnt_lsb_wrapped;                                //
+                            //
+                        endcase
+                //
+                2'd3: case (rcmb_xy_valid)
+                                            //
+                                            2'b00: begin
+                                                //
+                                                if (rcmb_msb_flag_delay_2) begin
+                                                    //
+                                                    rdy_adv <= ~rcmb_msb_flag_delay_1;
+                                                    //
+                                                end
+                                                //
+                                            end
+                                            //
+                                        endcase
+                //
+            endcase
+            //        
+        end
+
+
+    
+        // add ready for mode=3
+endmodule