Subversion Repositories xulalx25soc

///////////////////////////////////////////////////////////////////////////

//

// Filename:    ioslave

//

// Project:     XuLA2 board

//

// Purpose:     This handles a bunch of small, simple I/O registers.  To be

//              included here, the I/O register must take exactly a single

//      clock to access and never stall.

//

//      Particular peripherals include:

//              - the interrupt controller

//              - Realtime Clock

//              - Realtime clock Date

//              - A bus error register--records the address of the last

//                      bus error.  Cannot be written to, save by a bus error.

//      Other peripherals have been removed due to a lack of bus address space.

//

//

// Creator:     Dan Gisselquist, Ph.D.

//              Gisselquist Technology, LLC

//

///////////////////////////////////////////////////////////////////////////

//

// Copyright (C) 2015, Gisselquist Technology, LLC

//

// This program is free software (firmware): you can redistribute it and/or

// modify it under the terms of  the GNU General Public License as published

// by the Free Software Foundation, either version 3 of the License, or (at

// your option) any later version.

//

// This program is distributed in the hope that it will be useful, but WITHOUT

// ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or

// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

// for more details.

//

// License:     GPL, v3, as defined and found on www.gnu.org,

//              http://www.gnu.org/licenses/gpl.html

//

//

///////////////////////////////////////////////////////////////////////////

//

//

`include "builddate.v"

module  ioslave(i_clk,

                // Wishbone control

                i_wb_cyc, i_wb_stb, i_wb_we, i_wb_addr, i_wb_data,

                        o_wb_ack, o_wb_stall, o_wb_data,

                // GPIO wires

                i_gpio,

                o_gpio,

                // Other registers

                i_bus_err_addr,

                brd_interrupts, o_ints_to_zip_cpu, o_interrupt);

        parameter       NGPO=15, NGPI=15;

        input                   i_clk;

        // Wishbone control

        //      inputs...

        input                   i_wb_cyc, i_wb_stb, i_wb_we;

        input           [4:0]    i_wb_addr;

        input           [31:0]   i_wb_data;

        //      outputs...

        output  reg             o_wb_ack;

        output  wire            o_wb_stall;

        output  wire    [31:0]   o_wb_data;

        // GPIO

        input   [(NGPI-1):0]     i_gpio;

        output wire [(NGPO-1):0] o_gpio;

        // Other registers

        input           [31:0]   i_bus_err_addr;

        input           [5:0]    brd_interrupts;

        output  wire    [7:0]    o_ints_to_zip_cpu;

        output  wire            o_interrupt;

        wire    i_uart_rx_int, i_uart_tx_int, i_scop_int, i_flash_int,i_pwm_int;

        assign  i_uart_tx_int = brd_interrupts[5];

        assign  i_uart_rx_int = brd_interrupts[4];

        assign  i_pwm_int     = brd_interrupts[3];

        assign  i_scop_int    = brd_interrupts[2];

        assign  i_flash_int   = brd_interrupts[1];

        // reg          [31:0]  pwrcount;

        // reg          [31:0]  rtccount;

        wire            [31:0]   ictrl_data, gpio_data, date_data;

        reg     [31:0]   r_wb_data;

        reg             r_wb_addr;

        always @(posedge i_clk)

        begin

                r_wb_addr <= i_wb_addr[4];

                // if ((i_wb_cyc)&&(i_wb_stb)&&(i_wb_we)&&(~i_wb_addr[4]))

                // begin

                        // casez(i_wb_addr[3:0])

                        // // 4'h0: begin end // Reset register

                        // // 4'h1: begin end // Status/Control register

                        // // 4'h2: begin end // Reset register

                        // // 4'h3: begin end // Interrupt Control register

                        // // 4'h4: // R/O Power count

                        // // 4'h5: // RTC count

                        // default: begin end

                        // endcase

                // end else

                if ((i_wb_cyc)&&(i_wb_stb)&&(~i_wb_we))

                begin

                        casez(i_wb_addr[3:0])

                        4'h02: r_wb_data <= `DATESTAMP;

                        4'h03: r_wb_data <= ictrl_data;

                        4'h04: r_wb_data <= i_bus_err_addr;

                        4'h05: r_wb_data <= date_data;

                        4'h06: r_wb_data <= gpio_data;

                        default: r_wb_data <= 32'h0000;

                        endcase

                end

        end

        // The interrupt controller

        wire            ck_int;

        wire    [7:0]    interrupt_vector;

        assign  interrupt_vector = {

                        i_uart_tx_int, i_uart_rx_int, i_pwm_int, gpio_int,

                        i_scop_int, i_flash_int, ck_int, brd_interrupts[0] };

        icontrol #(8)   intcontroller(i_clk, 1'b0,

                                ((i_wb_cyc)&&(i_wb_stb)&&(i_wb_we)

                                        &&(i_wb_addr==5'h3)), i_wb_data,

                                ictrl_data, interrupt_vector,

                                o_interrupt);

        /*

        // The ticks since power up register

        initial pwrcount = 32'h00;

        always @(posedge i_clk)

                if (~ (&pwrcount))

                        pwrcount <= pwrcount+1;

        // The time since power up register

        reg     [15:0]  subrtc;

        reg             subpps;

        initial rtccount = 32'h00;

        initial subrtc = 16'h00;

        always @(posedge i_clk)

                { subpps, subrtc } <= subrtc + 16'd43;

        always @(posedge i_clk)

                rtccount <= rtccount + ((subpps)? 32'h1 : 32'h0);

        */

        //

        // GPIO controller

        //

        wire    gpio_int;

        wbgpio  #(NGPI, NGPO)

                gpiodev(i_clk, i_wb_cyc, (i_wb_stb)&&(i_wb_addr[4:0]==5'h6),

                        i_wb_we, i_wb_data, gpio_data, i_gpio, o_gpio,gpio_int);

        //

        // 4'b1xxx

        // BUS access to a real time clock (not calendar, just clock)

        //

        //

        wire    [31:0]   ck_data;

        wire            ck_ppd;

        rtclight #(32'h35afe5)

                theclock(i_clk, i_wb_cyc, (i_wb_stb)&&(i_wb_addr[4]),

                                i_wb_we, i_wb_addr[2:0], i_wb_data,

                        ck_data, ck_int, ck_ppd);

        wire            date_ack, date_stall;

        rtcdate thedate(i_clk, ck_ppd,

                        i_wb_cyc, (i_wb_stb)&&(i_wb_addr[3:0]==4'h5),

                                i_wb_we, i_wb_data,

                        date_ack, date_stall, date_data);

        always @(posedge i_clk)

                o_wb_ack <= (i_wb_stb)&&(i_wb_cyc);

        assign  o_wb_stall = 1'b0;

        assign  o_wb_data = (r_wb_addr)? ck_data : r_wb_data;

        //

        //

        assign  o_ints_to_zip_cpu = { i_uart_tx_int, i_uart_rx_int,

                        i_pwm_int, gpio_int, i_scop_int, i_flash_int,

                        ck_int, o_interrupt };

endmodule