design/sys/iop/niu/rtl/niu_smx_regflag.v

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// OpenSPARC T2 Processor File: niu_smx_regflag.v
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module niu_smx_regflag(
/*AUTOARG*/
   // Outputs
   rdata, rdata_bus,
   // Inputs
   clk, reset_l, set, rst0, rst1, set_addr, rst_addr0, rst_addr1,
   rst_first, rd, raddr
   );

// synopsys template

parameter ADDR_WIDTH= 6;
parameter ENTRY_SIZE= 1<<ADDR_WIDTH;


input clk;
input reset_l;
input set;
input rst0;
input rst1;
input [ADDR_WIDTH-1:0]  set_addr;
input [ADDR_WIDTH-1:0]  rst_addr0;
input [ADDR_WIDTH-1:0]  rst_addr1;
input rst_first;

input rd;
input [ADDR_WIDTH-1:0]  raddr;
output rdata;

output [ENTRY_SIZE-1:0] rdata_bus;

reg [ENTRY_SIZE-1:0] data;
reg rdata;

wire [ENTRY_SIZE-1:0] rdata_bus= data;

wire [ENTRY_SIZE-1:0] decode_rst0_n;
wire [ENTRY_SIZE-1:0] decode_rst1_n;
wire [ENTRY_SIZE-1:0] decode_set_n;
wire [ENTRY_SIZE-1:0] rst0_en_n= (decode_rst0_n & {ENTRY_SIZE{rst0}});
wire [ENTRY_SIZE-1:0] rst1_en_n= (decode_rst1_n & {ENTRY_SIZE{rst1}});
wire [ENTRY_SIZE-1:0] set_en_n= (decode_set_n & {ENTRY_SIZE{set}});
wire [ENTRY_SIZE-1:0] rst_en_n= rst0_en_n | rst1_en_n;
wire [ENTRY_SIZE-1:0] data_rst_n= data & ~rst_en_n;
wire [ENTRY_SIZE-1:0] data_set_n= data | set_en_n;

                // reset override set at same addr
wire [ENTRY_SIZE-1:0] rf_data_n= data_set_n & ~rst_en_n;
                // set override reset at same addr
wire [ENTRY_SIZE-1:0] sf_data_n= data_rst_n | set_en_n;

integer i;

  always @(posedge clk) begin
    if(!reset_l) begin
      for(i=0; i<ENTRY_SIZE; i=i+1)
        data[i]<= `SMX_PD  1'b0;
    end
    else begin
      if(rst0 | rst1 | set)
        data<= `SMX_PD (rst_first)? rf_data_n : sf_data_n;
    end
  end

  always @(posedge clk) begin
    if(rd) begin
      rdata<= `SMX_PD  data[raddr];
    end
  end


niu_smx_decode #(ADDR_WIDTH, ENTRY_SIZE) decode_set(
        .in (set_addr[ADDR_WIDTH-1:0]),
        .out (decode_set_n[ENTRY_SIZE-1:0])
        );
niu_smx_decode #(ADDR_WIDTH, ENTRY_SIZE) decode_rst0(
        .in (rst_addr0[ADDR_WIDTH-1:0]),
        .out (decode_rst0_n[ENTRY_SIZE-1:0])
        );
niu_smx_decode #(ADDR_WIDTH, ENTRY_SIZE) decode_rst1(
        .in (rst_addr1[ADDR_WIDTH-1:0]),
        .out (decode_rst1_n[ENTRY_SIZE-1:0])
        );


endmodule