verilog/rtl/scan_wrapper_341174480471589458.v

`default_nettype none
/*
`ifdef COCOTB
`define UNIT_DELAY #1
`define FUNCTIONAL
`define USE_POWER_PINS
`include "libs.ref/sky130_fd_sc_hd/verilog/primitives.v"
`include "libs.ref/sky130_fd_sc_hd/verilog/sky130_fd_sc_hd.v"
`endif
*/

module scan_wrapper_341174480471589458 (
    input wire clk_in,
    input wire data_in,
    input wire scan_select_in,
    input wire latch_enable_in,
    output wire clk_out,
    output wire data_out,
    output wire scan_select_out,
    output wire latch_enable_out
    );

    assign scan_select_out = scan_select_in;
    assign latch_enable_out = latch_enable_in;
    assign clk_out = clk_in;
    wire clk = clk_in;

    /*
    `ifdef COCOTB
    initial begin
        $dumpfile ("scan_wrapper.vcd");
        $dumpvars (0, scan_wrapper_lesson_1);
        #1;
    end
    `endif
    */

    parameter NUM_IOS = 8;

    // wires needed
    wire [NUM_IOS-1:0] scan_data_out;   // output of the each scan chain flop
    wire [NUM_IOS-1:0] scan_data_in;    // input of each scan chain flop
    wire               module_latch_in; // buffered version of latch_enable_in
    wire [NUM_IOS-1:0] module_data_in;  // the data that enters the user module
    wire [NUM_IOS-1:0] module_data_out; // the data from the user module

    // scan chain - link all the flops, with data coming from data_in
    assign scan_data_in = {scan_data_out[NUM_IOS-2:0], data_in};

    // end of the chain is a negedge FF to increase hold margin between blocks
    sky130_fd_sc_hd__dfrtn_1 out_flop (
`ifdef WITH_POWER
        .VPWR       (1'b1),
        .VGND       (1'b0),
`endif
        .RESET_B    (1'b1),
        .CLK_N      (clk),
        .D          (scan_data_out[NUM_IOS-1]),
        .Q          (data_out)
    );

    // scan flops have a mux on their inputs to choose either data from the user module or the previous flop's output
    // https://antmicro-skywater-pdk-docs.readthedocs.io/en/test-submodules-in-rtd/contents/libraries/sky130_fd_sc_ls/cells/sdfxtp/README.html
    `ifndef FORMAL
    `ifndef FORMAL_COMPAT
    sky130_fd_sc_hd__sdfxtp_1 scan_flop [NUM_IOS-1:0] (
`ifdef WITH_POWER
        .VPWR       (1'b1),
        .VGND       (1'b0),
`endif
        .CLK        (clk),
        .D          (scan_data_in),
        .SCD        (module_data_out),
        .SCE        (scan_select_in),
        .Q          (scan_data_out)
    );
    `endif
    `endif

    // Send output of scan chain directly
    assign module_data_in = scan_data_out;

    // Buffer latch signal
    sky130_fd_sc_hd__buf_2 latch_buf (
`ifdef WITH_POWER
        .VPWR       (1'b1),
        .VGND       (1'b0),
`endif
        .A          (latch_enable_in),
        .X          (module_latch_in)
    );

    // instantiate the wokwi module
    user_module_341174480471589458 user_module(
        .latch_in  (module_latch_in),
        .io_in     (module_data_in),
        .io_out    (module_data_out)
    );

endmodule