/*
 * Copyright 2020 The SkyWater PDK Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * SPDX-License-Identifier: Apache-2.0
*/

module sky130_fd_io__top_refgen (VINREF, VOUTREF, REFLEAK_BIAS,
                                 VCCD, VCCHIB, VDDA, VDDIO, VDDIO_Q, VSSD, VSSIO, VSSIO_Q,
                                 HLD_H_N, IBUF_SEL, OD_H, VOHREF, VREF_SEL, VREG_EN, VTRIP_SEL);
wire error_vsel;
output VINREF;
output VOUTREF;
inout REFLEAK_BIAS;
inout VCCD;
inout VCCHIB;
inout VDDA;
inout VDDIO;
inout VDDIO_Q;
inout VSSD;
inout VSSIO;
inout VSSIO_Q;
input HLD_H_N;
input IBUF_SEL;
input OD_H;
input VOHREF;
input VREF_SEL;
input VREG_EN;
input VTRIP_SEL;
reg [2:0] dm_final;
reg       slow_final, vtrip_sel_final, inp_dis_final, hld_ovr_final;
reg [2:0] dm;
reg       slow, inp_dis, hld_ovr;
reg [1:0] vsel;
wire  pwr_good_active_mode    = (VDDIO_Q===1) && (VDDIO===1)  && (VSSD===0)    && (VCCD===1);
wire  pwr_good_hold_mode      = (VDDIO_Q===1) && (VDDIO===1)  && (VSSD===0);
always @(*)
begin
    if (^OD_H===1'bx || !pwr_good_hold_mode || (OD_H===0 && ^HLD_H_N===1'bx))
    begin
        dm_final 	= 3'bxxx;
        slow_final 	= 1'bx;
        vtrip_sel_final	= 1'bx;
        inp_dis_final 	= 1'bx;
        hld_ovr_final 	= 1'bx;
    end
    else if (OD_H===1)
    begin
        dm_final 	= 3'b000;
        slow_final 	= 1'b0;
        vtrip_sel_final	= 1'b0;
        inp_dis_final 	= 1'b0;
        hld_ovr_final 	= 1'b0;
    end
    else if (HLD_H_N===1)
    begin
        dm_final 	= (^dm[2:0] === 1'bx	|| !pwr_good_active_mode) ? 3'bxxx : dm;
        slow_final 	= (^slow 	=== 1'bx	|| !pwr_good_active_mode) ? 1'bx   : slow;
        vtrip_sel_final	= (^VTRIP_SEL 	=== 1'bx	|| !pwr_good_active_mode) ? 1'bx   : VTRIP_SEL;
        inp_dis_final 	= (^inp_dis	=== 1'bx	|| !pwr_good_active_mode) ? 1'bx   : inp_dis;
        hld_ovr_final 	= (^hld_ovr 	=== 1'bx	|| !pwr_good_active_mode) ? 1'bx   : hld_ovr;
    end
end
reg dis_err_msgs;
initial
begin
    dis_err_msgs = 1'b1;
`ifdef SKY130_FD_IO_TOP_REFGEN_DIS_ERR_MSGS
`else
    #1;
    dis_err_msgs = 1'b0;
`endif
end
assign error_vsel = (vsel[1]===1 && vsel[0]===1);
always @(*)
begin
    if (!dis_err_msgs)
    begin
        if (error_vsel==1) $display(" ===ERROR=== sky130_fd_io__top_refgen : %m : Incorrect inputs on vsel[1:0] = 11",$stime);
    end
end
endmodule