xilinx/xc7/tests/mmcm/mmcm_ext_basys3_bottom.v

`include "mmcme2_test.v"

`default_nettype none

// ============================================================================

module top
(
input  wire clk,

input  wire [7:0] sw,
output wire [7:0] led,

input  wire jc1, // unused
output wire jc2,
input  wire jc3, // unused
input  wire jc4
);

// ============================================================================
// Reset generator
wire CLK;
BUFG bufgctrl(.I(clk), .O(CLK));

reg [3:0] rst_sr;
initial rst_sr <= 4'hF;

always @(posedge CLK)
    if (sw[0])
        rst_sr <= 4'hF;
    else
        rst_sr <= rst_sr >> 1;

wire RST = rst_sr[0];

// ============================================================================
// The tester

mmcme2_test #
(
.FEEDBACK   ("EXTERNAL")
)
mmcme2_test
(
.CLK        (clk),
.RST        (RST),

.CLKFBOUT   (jc2),
.CLKFBIN    (jc4),

.I_PWRDWN   (sw[1]),
.I_CLKINSEL (sw[2]),

.O_LOCKED   (led[6]),
.O_CNT      (led[5:0])
);

assign led[7] = |sw[7:3];

endmodule