modifying histograms module to avoid use of the double pixel frequency clock

includes/x393_simulation_parameters.vh

@@ -61,7 +61,7 @@
 
     parameter HISTOGRAM_LEFT =           0,   // 2;   // left   
     parameter HISTOGRAM_TOP =            8,   // 2,   // top
-    parameter HISTOGRAM_WIDTH =          6,   // width
+    parameter HISTOGRAM_WIDTH =         22,  // 6,  // width
     parameter HISTOGRAM_HEIGHT =         6,   // height
     parameter HISTOGRAM_START_PAGE =    20'h12345,
     parameter FRAME_WIDTH_ROUND_BITS =   9,  // multiple of 512 pixels (32 16-byte bursts) (11 - ful SDRAM page)

memctrl/mcntrl_linear_rw.v

@@ -390,7 +390,7 @@ module  mcntrl_linear_rw #(
         
         if (mrst) xfer_skipped <= 0;
         else      xfer_skipped <= start_not_partial && skip_run;
-        
+            
 //        if  (mrst || frame_start_delayed) frame_start_pending <= 0;
         if  (mrst) frame_start_pending <= 0;
 //        else       frame_start_pending <= {frame_start_pending[0], busy_r && (frame_start_pending[0] | frame_start)};

sensor/sens_histogram.v

@@ -35,7 +35,6 @@ module  sens_histogram #(
 `endif        
     
 )(
-//    input         rst,
     input         mrst,      // @posedge mclk, sync reset
     input         prst,      // @posedge pclk, sync reset
     input         pclk,   // global clock input, pixel rate (96MHz for MT9P006)
@@ -55,16 +54,12 @@ module  sens_histogram #(
     input   [7:0] cmd_ad,      // byte-serial command address/data (up to 6 bytes: AL-AH-D0-D1-D2-D3 
     input         cmd_stb,      // strobe (with first byte) for the command a/d
     input         monochrome    // tie to 0 to reduce hardware
-//    ,output debug_mclk
 `ifdef DEBUG_RING       
     ,output                       debug_do, // output to the debug ring
      input                        debug_sl, // 0 - idle, (1,0) - shift, (1,1) - load // SuppressThisWarning VEditor - not used
      input                        debug_di  // input from the debug ring
 `endif         
 );
-`ifdef DEBUG_RING
-//     assign  debug_do = debug_di;
-`endif        
 
     localparam PXD_2X_LATENCY = 2;
     reg         hist_bank_pclk;
@@ -140,11 +135,10 @@ module  sens_histogram #(
     reg           hist_xfer_busy; // @pclk, during histogram readout , immediately after woi (no gaps)
     reg           wait_readout;   // only used in NOBUF mode, in outher modes readout is expected to be always finished in time
     
-//    reg           debug_vert_woi_r;
-    
+`ifdef DEBUG_RING
     reg    [15:0] debug_line_cntr;
     reg    [15:0] debug_lines;
-    
+`endif    
     
     assign set_left_top_w =     pio_stb && (pio_addr == HISTOGRAM_LEFT_TOP );
     assign set_width_height_w = pio_stb && (pio_addr == HISTOGRAM_WIDTH_HEIGHT );
@@ -179,16 +173,14 @@ module  sens_histogram #(
     reg        monochrome_pclk;
     reg        monochrome_2x;
     
-//    assign debug_mclk = hist_done_mclk;
-//    assign debug_mclk = set_width_height_w;
-
+`ifdef DEBUG_RING
     always @ (posedge pclk) begin
         if      (sof)          debug_line_cntr <= 0;
         else if (line_start_w) debug_line_cntr <= debug_line_cntr + 1;
         
         if      (sof)          debug_lines <= debug_line_cntr;
     end
-    
+`endif    
     
     always @ (posedge pclk) begin
         if (!hact) pxd_wa <= 0;
@@ -215,7 +207,6 @@ module  sens_histogram #(
     end
     
     // process WOI
-//    wire  eol = !hact && hact_d[0];
     always @ (posedge pclk) begin
         hact_d <= {hact_d[0],hact};
         if      (!en)           pre_first_line <= 0;
@@ -229,9 +220,6 @@ module  sens_histogram #(
         if (!en ||(pre_first_line && !hact))  vert_woi <= 0;
         else if (vcntr_zero_w & line_start_w) vert_woi <= top_margin;
         
-//        debug_vert_woi_r <= vcntr_zero_w && vert_woi; // vert_woi;
-        
-//        hist_done <= vcntr_zero_w && vert_woi && line_start_w; // hist done never asserted, line_start_w - active
         hist_done <= vert_woi && (eof || (vcntr_zero_w && line_start_w)); // hist done never asserted, line_start_w - active
         
         if   (!en || hist_done)               frame_active <= 0;
@@ -253,8 +241,6 @@ module  sens_histogram #(
         else if (hcntr_zero_w && left_margin) hcntr <= width_m1;
         else if (left_margin || hor_woi)      hcntr <= hcntr - 1;
         
-//        if (hor_woi) hist_d <= hist_di;
-        
         if      (!en)                                          hist_bank_pclk <= 0;
         else if (hist_done && (HISTOGRAM_RAM_MODE != "NOBUF")) hist_bank_pclk <= !hist_bank_pclk;
         // hist_xfer_busy to extend en
@@ -279,13 +265,11 @@ module  sens_histogram #(
         else if (!hact)                   bayer_pclk[0] <= XOR_HIST_BAYER[0];
         else                              bayer_pclk[0] <= ~bayer_pclk[0]; 
 
-//line_start_w        
     end
 
     always @(posedge pclk2x) begin
         monochrome_2x <= monochrome;
         hist_en_pclk2x <= hist_en;
-//        hist_rst_pclk2x <= hist_rst;
         pxd_ra_start <= left[3:0];
         
         if (!hist_en_pclk2x || hlstart || !(hor_woi_2x || (|woi)))  pclk_sync <= 0;
@@ -306,8 +290,6 @@ module  sens_histogram #(
             hist_addr_d2 <= hist_addr_d;
             same_addr1 <= monochrome_2x && woi[0] && woi[1] && (hist_addr_d  == hist_addr); // reduce hardware if hard-wire to gnd
             same_addr2 <=                  woi[0] && woi[2] && (hist_addr_d2 == hist_addr);
-//            if (same_addr) to_inc <= inc_r;
-//            else           to_inc <= hist_new;
             if      (same_addr1) to_inc <= inc_r; // only used in monochrome mode
             else if (same_addr2) to_inc <= inc_sat;
             else                 to_inc <= hist_new;
@@ -317,7 +299,6 @@ module  sens_histogram #(
             else                                     inc_sat <= {14'b0,inc_r[17:0]};
         end
         hist_rwen <= (woi[0] & ~pclk_sync) || (woi[2] & pclk_sync);
-//        hist_regen <= {hist_regen[1:0], woi[0] & ~pclk_sync};
         hist_regen <= {hist_regen[0], woi[0] & ~pclk_sync};
         hist_we <= woi[2] & pclk_sync;
         
@@ -325,10 +306,6 @@ module  sens_histogram #(
         else if (woi[2] & pclk_sync) hist_rwaddr <= hist_addr_d2;
         
         inc_r <= to_inc + 1;
-
-//        if      (HISTOGRAM_RAM_MODE != "BUF18")  inc_r <= inc_w;
-//        else if (inc_w[18])                      inc_r <= 32'h3fff; // maximal value
-//        else                                     inc_r <= {14'b0,inc_w[17:0]};
         
     end
     // after hist_out was off, require inactive grant before sending rq
@@ -336,25 +313,19 @@ module  sens_histogram #(
     
     always @ (posedge mclk) begin
         en_mclk <= en;
-        monochrome_pclk <= monochrome;
+//        monochrome_pclk <= monochrome;
         if      (!en_mclk)       hist_out <= 0;
         else if (hist_done_mclk) hist_out <= 1;
         else if (&hist_raddr)    hist_out <= 0;
         
         hist_out_d <= hist_out;
         // reset address each time new transfer is started
-//        if      (!en_mclk || (hist_out && !hist_out_d)) hist_raddr <= 0;
         if      (!hist_out)  hist_raddr <= 0;
         else if (hist_re[0]) hist_raddr <= hist_raddr + 1;
         
-//        if      (!en_mclk)             hist_rq_r <= 0;
-//        else if (hist_out && !hist_re) hist_rq_r <= 1;
-
-//        hist_rq_r <= en_mclk && hist_out && !(&hist_raddr);
 // prevent starting rq if grant is still on (back-to-back)
         if      (!hist_out)   en_rq_start <= 0;
         else if (!hist_grant) en_rq_start <= 1;
-//        hist_rq_r <= en_mclk && hist_out && !(&hist_raddr) && ((|hist_raddr[9:0]) || !hist_grant);
         hist_rq_r <= en_mclk && hist_out && !(&hist_raddr) && en_rq_start;
         
         if      (!hist_out || (&hist_raddr[7:0])) hist_re[0] <= 0;
@@ -372,6 +343,7 @@ module  sens_histogram #(
         else if ((HISTOGRAM_RAM_MODE == "NOBUF") && hist_done) wait_readout <= 1;
         else if (hist_xfer_done)                               wait_readout <= 0;
     
+        monochrome_pclk <= monochrome;
     end
 
 `ifdef DEBUG_RING
@@ -386,26 +358,11 @@ module  sens_histogram #(
         .debug_di   (debug_di), // input
         .debug_sl   (debug_sl), // input
         .debug_do   (debug_do), // output
-//        .rd_data   ({height_m1[15:0], vcntr[15:0], width_m1[15:0],  hcntr[15:0]}), // input[31:0] 
         .rd_data   ({debug_lines[15:0], debug_line_cntr[15:0], width_m1[15:0],  hcntr[15:0]}), // input[31:0] 
-//debug_lines <= debug_line_cntr        
         .wr_data    (), // output[31:0]  - not used
         .stb        () // output  - not used
     );
 `endif
-
-/*
-    pulse_cross_clock pulse_cross_clock_debug_mclk_i (
-        .rst         (prst), // input
-        .src_clk     (pclk), // input
-        .dst_clk     (mclk), // input
-//        .in_pulse    (vert_woi && !debug_vert_woi_r), // line_start_w), // input vcntr_zero_w
-//        .in_pulse    (vcntr_zero_w && !debug_vert_woi_r), // line_start_w), // input 
-        .in_pulse    (vcntr_zero_w && vert_woi && !debug_vert_woi_r), // line_start_w), // input 
-        .out_pulse   (debug_mclk),    // output
-        .busy() // output
-    );
-*/
     
     cmd_deser #(
         .ADDR        (HISTOGRAM_ADDR),
@@ -474,13 +431,6 @@ module  sens_histogram #(
         .out_pulse   (hist_xfer_done),    // output
         .busy() // output
     );
-/*   
-    clk_to_clk2x clk_to_clk2x_i (
-        .clk         (pclk), // input
-        .clk2x       (pclk2x), // input
-        .clk_sync    (pclk_sync) // output
-    );
-*/    
     //TODO:  make it double cycle in timing
 
     // select between 18-bit wide histogram data using a single BRAM or 2 BRAMs having full 32 bits    

sensor/sensor_channel.v

@@ -993,6 +993,40 @@ module  sensor_channel#(
         .bayer_out   (gamma_bayer)     // output [1:0]
     );
 
+// Debugging - adding a parallel to 0:0 module
+        wire        hist_rq_debug;
+        wire [31:0] hist_do_debug; 
+        wire        hist_dv_debug; 
+
+    sens_histogram_snglclk #(
+                .HISTOGRAM_RAM_MODE     ("BUF32"),
+//                .HISTOGRAM_RAM_MODE     (HISTOGRAM_RAM_MODE),
+                .HISTOGRAM_ADDR         (HISTOGRAM_ADDR0),
+                .HISTOGRAM_ADDR_MASK    (HISTOGRAM_ADDR_MASK),
+                .HISTOGRAM_LEFT_TOP     (HISTOGRAM_LEFT_TOP),
+                .HISTOGRAM_WIDTH_HEIGHT (HISTOGRAM_WIDTH_HEIGHT)
+`ifdef DEBUG_RING
+                ,.DEBUG_CMD_LATENCY     (DEBUG_CMD_LATENCY) 
+`endif        
+    ) sens_histogram_snglclk_chn0_0_i (
+                .mrst       (mrst), // input
+                .prst       (prsts), // input
+                .pclk       (pclk), // input
+                .sof        (gamma_sof_out), // input
+                .eof        (gamma_eof_out), // input
+                .hact       (gamma_hact_out), // input
+                .hist_di    (gamma_pxd_out), // input[7:0] 
+                .mclk       (mclk), // input
+                .hist_en    (hist_en[0]), // input
+                .hist_rst   (!hist_nrst[0]), // input
+                .hist_rq    (hist_rq_debug), // output
+                .hist_grant (hist_gr[0]), // input
+                .hist_do    (hist_do_debug), // output[31:0] 
+                .hist_dv    (hist_dv_debug), // output reg 
+                .cmd_ad     (cmd_ad), // input[7:0] 
+                .cmd_stb    (cmd_stb) // input
+    );
+
     // TODO: Use generate to generate 1-4 histogram modules
     generate
         if (HISTOGRAM_ADDR0 >=0)

wrap/ram18t_var_w_var_r.v

+/*******************************************************************************
+ * Module: ram18t_var_w_var_r
+ * Date:2015-05-29  
+ * Author: Andrey Filippov     
+ * Description:  Dual port memory wrapper, with variable width write and variable
+ * width read,  using "TDP" mode of RAMB36E1. Same R/W widths in each port.
+ * Does not use parity bits to increase total data width, width down to 1 are valid.
+ *
+ * Copyright (c) 2015 Elphel, Inc.
+ * ram18t_var_w_var_r.v is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ *  ram18t_var_w_var_r.v is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/> .
+ *******************************************************************************/
+`timescale 1ns/1ps
+`include "system_defines.vh" 
+/*
+   Address/data widths
+   Connect unused data to 1b0, unused addresses - to 1'b1
+   
+   RAMB18E1 in True Dual Port (TDP) Mode - each port individually
+   +-----------+---------+---------+---------+
+   |Data Width | Address |   Data  | Parity  |
+   +-----------+---------+---------+---------+
+   |     1     | A[13:0] | D[0]    |  ---    |
+   |     2     | A[13:1] | D[1:0]  |  ---    |
+   |     4     | A[13:2] | D[3:0[  |  ---    |
+   |     9     | A[13:3] | D[7:0]  | DP[0]   |
+   |    18     | A[13:4] | D[15:0] | DP[1:0] |
+   +-----------+---------+---------+---------+
+
+   RAMB18E1 in Simple Dual Port (SDP) Mode
+   one of the ports (r or w) - 32/36 bits, other - variable 
+   +------------+---------+---------+---------+
+   |Data Widths | Address |   Data  | Parity  |
+   +------------+---------+---------+---------+
+   |   32/  1   | A[13:0] | D[0]    |  ---    |
+   |   32/  2   | A[13:1] | D[1:0]  |  ---    |
+   |   32/  4   | A[13:2] | D[3:0[  |  ---    |
+   |   36/  9   | A[13:3] | D[7:0]  | DP[0]   |
+   |   36/ 18   | A[13:4] | D[15:0] | DP[1:0] |
+   |   36/ 36   | A[13:5] | D[31:0] | DP[3:0] |
+   +------------+---------+---------+---------+
+   
+   RAMB36E1 in True Dual Port (TDP) Mode - each port individually
+   +-----------+---------+---------+---------+
+   |Data Width | Address |   Data  | Parity  |
+   +-----------+---------+---------+---------+
+   |     1     | A[14:0] | D[0]    |  ---    |
+   |     2     | A[14:1] | D[1:0]  |  ---    |
+   |     4     | A[14:2] | D[3:0[  |  ---    |
+   |     9     | A[14:3] | D[7:0]  | DP[0]   |
+   |    18     | A[14:4] | D[15:0] | DP[1:0] |
+   |    36     | A[14:5] | D[31:0] | DP[3:0] |
+   |1(Cascade) | A[15:0] | D[0]    |  ---    |
+   +-----------+---------+---------+---------+
+
+   RAMB36E1 in Simple Dual Port (SDP) Mode
+   one of the ports (r or w) - 64/72 bits, other - variable 
+   +------------+---------+---------+---------+
+   |Data Widths | Address |   Data  | Parity  |
+   +------------+---------+---------+---------+
+   |   64/  1   | A[14:0] | D[0]    |  ---    |
+   |   64/  2   | A[14:1] | D[1:0]  |  ---    |
+   |   64/  4   | A[14:2] | D[3:0[  |  ---    |
+   |   64/  9   | A[14:3] | D[7:0]  | DP[0]   |
+   |   64/ 18   | A[14:4] | D[15:0] | DP[1:0] |
+   |   64/ 36   | A[14:5] | D[31:0] | DP[3:0] |
+   |   64/ 72   | A[14:6] | D[63:0] | DP[7:0] |
+   +------------+---------+---------+---------+
+*/
+
+module  ram18t_var_w_var_r
+#(
+  parameter integer REGISTERS_A = 0, // 1 - registered output
+  parameter integer REGISTERS_B = 0, // 1 - registered output
+  parameter integer LOG2WIDTH_A = 4,  // WIDTH= 9  << (LOG2WIDTH - 3)
+  parameter integer LOG2WIDTH_B = 4,  // WIDTH= 9  << (LOG2WIDTH - 3)
+  parameter WRITE_MODE_A =        "NO_CHANGE", //Valid: "WRITE_FIRST", "READ_FIRST", "NO_CHANGE"
+  parameter WRITE_MODE_B =        "NO_CHANGE"  //Valid: "WRITE_FIRST", "READ_FIRST", "NO_CHANGE"
+`ifdef PRELOAD_BRAMS
+    ,
+    `include "includes/ram36_declare_init.vh"
+`endif
+ )(
+      input                               clk_a,     // clock for port A
+      input            [13-LOG2WIDTH_A:0] addr_a,    // address port A
+      input                               en_a,      // enable port A (read and write)
+      input                               regen_a,   // output register enable port A
+      input                               we_a,      // write port enable port A
+      output     [(1 << LOG2WIDTH_A)-1:0] data_out_a,// data out port A
+      input      [(1 << LOG2WIDTH_A)-1:0] data_in_a, // data in port A
+      
+      input                               clk_b,     // clock for port BA
+      input            [13-LOG2WIDTH_B:0] addr_b,    // address port B
+      input                               en_b,      // read enable port B
+      input                               regen_b,   // output register enable port B
+      input                               we_b,      // write port enable port B
+      output     [(1 << LOG2WIDTH_B)-1:0] data_out_b,// data out port B
+      input      [(1 << LOG2WIDTH_B)-1:0] data_in_b  // data in port B
+);
+    localparam  PWIDTH_A = (LOG2WIDTH_A > 2)? (9 << (LOG2WIDTH_A - 3)): (1 << LOG2WIDTH_A);
+    localparam  PWIDTH_B = (LOG2WIDTH_B > 2)? (9 << (LOG2WIDTH_B - 3)): (1 << LOG2WIDTH_B);
+    localparam  WIDTH_A  = 1 << LOG2WIDTH_A;
+    localparam  WIDTH_B  = 1 << LOG2WIDTH_B;
+    
+    wire          [15:0] data_out16_a;
+    assign data_out_a=data_out16_a[WIDTH_A-1:0];
+
+    wire          [15:0] data_out16_b;
+    assign data_out_b=data_out16_b[WIDTH_B-1:0];
+
+
+    wire [WIDTH_A+15:0] data_in_ext_a =  {16'b0,data_in_a[WIDTH_A-1:0]};
+    wire         [15:0] data_in16_a =    data_in_ext_a[15:0];
+
+    wire [WIDTH_B+15:0] data_in_ext_b =  {16'b0,data_in_b[WIDTH_B-1:0]};
+    wire         [15:0] data_in16_b =    data_in_ext_b[15:0];
+
+    RAMB18E1
+    #(
+    .RSTREG_PRIORITY_A         ("RSTREG"),       // Valid: "RSTREG" or "REGCE"
+    .RSTREG_PRIORITY_B         ("RSTREG"),       // Valid: "RSTREG" or "REGCE"
+    .DOA_REG                   (REGISTERS_A),    // Valid: 0 (no output registers) and 1 - one output register (in SDP - to lower 18)
+    .DOB_REG                   (REGISTERS_B),    // Valid: 0 (no output registers) and 1 - one output register (in SDP - to lower 18)
+    .READ_WIDTH_A              (PWIDTH_A),       // Valid: 0,1,2,4,9,18 and in SDP mode - 36 (should be 0 if port is not used)
+    .READ_WIDTH_B              (PWIDTH_B),       // Valid: 0,1,2,4,9,18 and in SDP mode - 36 (should be 0 if port is not used)
+    .WRITE_WIDTH_A             (PWIDTH_A),       // Valid: 0,1,2,4,9,18 and in SDP mode - 36 (should be 0 if port is not used)
+    .WRITE_WIDTH_B             (PWIDTH_B),       // Valid: 0,1,2,4,9,18 and in SDP mode - 36 (should be 0 if port is not used)
+    .RAM_MODE                  ("TDP"),          // Valid "TDP" (true dual-port) and "SDP" - simple dual-port
+    .WRITE_MODE_A              (WRITE_MODE_A),   // Valid: "WRITE_FIRST", "READ_FIRST", "NO_CHANGE"
+    .WRITE_MODE_B              (WRITE_MODE_B),   // Valid: "WRITE_FIRST", "READ_FIRST", "NO_CHANGE"
+    .RDADDR_COLLISION_HWCONFIG ("DELAYED_WRITE"),// Valid: "DELAYED_WRITE","PERFORMANCE" (no access to the same page)
+    .SIM_COLLISION_CHECK       ("ALL"),          // Valid: "ALL", "GENERATE_X_ONLY", "NONE", and "WARNING_ONLY"
+    .INIT_FILE                 ("NONE"),         // "NONE" or filename with initialization data
+    .SIM_DEVICE                ("7SERIES")      // Simulation device family - "VIRTEX6", "VIRTEX5" and "7_SERIES" // "7SERIES"
+`ifdef PRELOAD_BRAMS
+    `include "includes/ram18_pass_init.vh"
+`endif
+    
+    ) RAMB18E1_i
+    (
+        // Port A (Read port in SDP mode):
+        .DOADO           (data_out16_a),    // Port A data/LSB data[15:0], output
+        .DOPADOP         (),                // Port A parity/LSB parity[1:0], output
+        .DIADI           (data_in16_a),     // Port A data/LSB data[15:0], input
+        .DIPADIP         (2'b0),            // Port A parity/LSB parity[1:0], input
+        .ADDRARDADDR     ({addr_a,{LOG2WIDTH_A{1'b1}}}),  // Port A (read port in SDP) address [13:0], unused should be high, input
+        .CLKARDCLK       (clk_a),           // Port A (read port in SDP) clock, input
+        .ENARDEN         (en_a),            // Port A (read port in SDP) Enable, input
+        .REGCEAREGCE     (regen_a),         // Port A (read port in SDP) register enable, input
+        .RSTRAMARSTRAM   (1'b0),            // Port A (read port in SDP) set/reset, input
+        .RSTREGARSTREG   (1'b0),            // Port A (read port in SDP) register set/reset, input
+        .WEA             ({2{we_a}}),       // Port A (read port in SDP) Write Enable[1:0], input
+        // Port B
+        .DOBDO           (data_out16_b),    // Port B data/MSB data[31:0], output
+        .DOPBDOP         (),                // Port B parity/MSB parity[3:0], output
+        .DIBDI           (data_in16_b),     // Port B data/MSB data[31:0], input
+        .DIPBDIP         (2'b0),            // Port B parity/MSB parity[3:0], input
+        .ADDRBWRADDR     ({addr_b,{LOG2WIDTH_B{1'b1}}}), // Port B (read port in SDP) address [13:0], unused should be high, input
+        .CLKBWRCLK       (clk_b),           // Port B (write port in SDP) clock, input
+        .ENBWREN         (en_b),            // Port B (write port in SDP) Enable, input
+        .REGCEB          (regen_b),         // Port B (write port in SDP) register enable, input
+        .RSTRAMB         (1'b0),            // Port B (write port in SDP) set/reset, input
+        .RSTREGB         (1'b0),            // Port B (write port in SDP) register set/reset, input
+        .WEBWE           ({4{we_b}})        // Port B (write port in SDP) Write Enable[3:0], input
+    );
+
+endmodule
+