Initial commit of OpenSPARC T2 design and verification files.

[OpenSPARC-T2-DV] / design / sys / iop / ccu / rtl / ccu_hm_dr_reset_gen.v

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// 
// OpenSPARC T2 Processor File: ccu_hm_dr_reset_gen.v
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module ccu_hm_dr_reset_gen (
	rst_out_n,
	clk,
	shift_amt,
	aligned,
    div_msb, 
	rst_n
);

output rst_out_n;
input clk;
input [4:0] shift_amt;
input aligned;
input div_msb; 
input rst_n;

wire rst_out_n;
wire clk;
wire [4:0] shift_amt;
wire aligned;
wire div_msb; 
wire [1:0] align_shift;
wire rst_n;

wire pulse_rst_n;
wire pulse_rst1_n;		// eco 1.1 - mh157021
wire pulse_rst2_n;		// eco 1.2 - mh157021
wire pulse_rst1_n_in;	// eco 1.3 - mh157021
wire rst;
reg  dr_rst_n;
wire dr_rst_n_q;



assign rst = ~rst_n;

assign rst_out_n = (div_msb) ? dr_rst_n : dr_rst_n_q ;

always @(posedge clk) begin  // later convert to async reset 
	if (!rst_n) 
		dr_rst_n <= 1'b0;
	else begin
		if (pulse_rst2_n) 	// eco 1.4 - mh157021 - wire change from pulse_rst_n
			dr_rst_n <= 1'b1;
		else 
			dr_rst_n <= dr_rst_n; 
	end
end	

my_msff_arst_4x	dr_rst_n_ff ( 
	.q(dr_rst_n_q), 
	.so(), 
	.d(dr_rst_n), 
	.l1clk(clk), 
	.si(1'b0), 
	.siclk(1'b0), 
	.soclk(1'b0), 
	.reset(rst) 
);


my_msff_arst_4x	pulse_wait ( // eco 1.5 - mh157021
	.q(pulse_rst1_n), 
	.so(), 
	.d(pulse_rst1_n_in), 
	.l1clk(clk), 
	.si(1'b0), 
	.siclk(1'b0), 
	.soclk(1'b0), 
	.reset(rst) 
);

assign pulse_rst1_n_in = pulse_rst1_n | pulse_rst_n;	// eco 1.6 - mh157021 - feedback
assign pulse_rst2_n    = pulse_rst1_n & pulse_rst_n;	// eco 1.7 - mh157021 - 2nd pulse goes thru 


// ***********************************************
// shift dr reset +4 cycle to reference edge 
// ***********************************************

ccu_hm_pulse_shift dr_reset_shift (
	.rst_n 		(rst_n),
	.clk 		(clk),
	.shift 		(shift_amt),	
 	.pulse_in 	(aligned),
	.pulse_out	(pulse_rst_n)
);

endmodule