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rehayes |
////////////////////////////////////////////////////////////////////////////////
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//
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// WISHBONE revB.2 compliant Programable Interrupt Timer - Top-level
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//
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// Author: Bob Hayes
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// rehayes@opencores.org
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//
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// Downloaded from: http://www.opencores.org/projects/pit.....
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//
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////////////////////////////////////////////////////////////////////////////////
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// Copyright (c) 2011, Robert Hayes
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//
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// All rights reserved.
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are met:
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above copyright
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// notice, this list of conditions and the following disclaimer in the
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// documentation and/or other materials provided with the distribution.
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// * Neither the name of the nor the
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// names of its contributors may be used to endorse or promote products
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// derived from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY Robert Hayes ''AS IS'' AND ANY
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// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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// DISCLAIMED. IN NO EVENT SHALL Robert Hayes BE LIABLE FOR ANY
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// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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////////////////////////////////////////////////////////////////////////////////
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// 45678901234567890123456789012345678901234567890123456789012345678901234567890
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module pit_top #(parameter ARST_LVL = 1'b0, // asynchronous reset level
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parameter PRE_COUNT_SIZE = 15, // Prescale Counter size
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parameter COUNT_SIZE = 16, // Main counter size
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parameter DECADE_CNTR = 1'b1, // Prescale rollover decode
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parameter NO_PRESCALE = 1'b0, // Remove prescale function
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parameter SINGLE_CYCLE = 1'b0, // No bus wait state added
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parameter DWIDTH = 16) // Data bus width
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(
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// Wishbone Signals
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output [DWIDTH-1:0] wb_dat_o, // databus output
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output wb_ack_o, // bus cycle acknowledge output
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input wb_clk_i, // master clock input
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input wb_rst_i, // synchronous active high reset
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input arst_i, // asynchronous reset
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input [2:0] wb_adr_i, // lower address bits
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input [DWIDTH-1:0] wb_dat_i, // databus input
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input wb_we_i, // write enable input
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input wb_stb_i, // stobe/core select signal
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input wb_cyc_i, // valid bus cycle input
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input [1:0] wb_sel_i, // Select byte in word bus transaction
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// PIT IO Signals
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output pit_o, // PIT output pulse
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output pit_irq_o, // PIT interrupt request signal output
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output cnt_flag_o, // PIT Flag Out
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output cnt_sync_o, // PIT Master Enable for Slave PIT's
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input ext_sync_i // Counter enable from Master PIT
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);
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logic [COUNT_SIZE-1:0] mod_value; // Main Counter Modulo
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logic [COUNT_SIZE-1:0] cnt_n; // PIT Counter Value
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logic async_rst_b; // Asyncronous reset
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logic sync_reset; // Syncronous reset
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logic [ 3:0] write_regs; // Control register write strobes
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logic prescale_out; //
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logic pit_flg_clr; // Clear PIT Rollover Status Bit
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logic pit_slave; // PIT in Slave Mode, ext_sync_i selected
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logic [ 3:0] pit_pre_scl; // Prescaler modulo
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logic counter_sync; //
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// Wishbone Bus interface
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pit_wb_bus #(.ARST_LVL(ARST_LVL),
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.SINGLE_CYCLE(SINGLE_CYCLE),
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.DWIDTH(DWIDTH))
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wishbone(*,
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.irq_source ( cnt_flag_o ),
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.read_regs ( // in -- status register bits
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{ cnt_n,
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mod_value,
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{pit_slave, DECADE_CNTR, NO_PRESCALE, 1'b0, pit_pre_scl,
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5'b0, cnt_flag_o, pit_ien, cnt_sync_o}
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}
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)
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);
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// -----------------------------------------------------------------------------
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pit_regs #(.ARST_LVL(ARST_LVL),
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.COUNT_SIZE(COUNT_SIZE),
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.NO_PRESCALE(NO_PRESCALE),
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.DWIDTH(DWIDTH))
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regs(*,
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.bus_clk ( wb_clk_i ),
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.write_bus ( wb_dat_i )
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);
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// -----------------------------------------------------------------------------
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pit_prescale #(.COUNT_SIZE(PRE_COUNT_SIZE),
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.DECADE_CNTR(DECADE_CNTR),
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.NO_PRESCALE(NO_PRESCALE))
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prescale(*,
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.bus_clk ( wb_clk_i ),
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.divisor ( pit_pre_scl )
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);
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// -----------------------------------------------------------------------------
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pit_count #(.COUNT_SIZE(COUNT_SIZE))
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counter(*,
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.bus_clk ( wb_clk_i )
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);
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endmodule // pit_top
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