| Line 1... |
Line 1... |
--##############################################################################
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--##############################################################################
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-- ION MIPS-compatible CPU demo on Terasic DE-1 Cyclone-II starter board
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-- ION MIPS-compatible CPU demo on Terasic DE-1 Cyclone-II starter board
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--##############################################################################
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--##############################################################################
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-- This module is little more than a wrapper around the SoC.
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-- This module is little more than a wrapper around the SoC.
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-- Synthesize with 'speed' optimization for best results.
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--------------------------------------------------------------------------------
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-- Switch 9 (leftmost) is used as reset.
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--------------------------------------------------------------------------------
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--------------------------------------------------------------------------------
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-- NOTE: See note at bottom of file about optional use of PLL.
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-- NOTE: See note at bottom of file about optional use of PLL.
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--##############################################################################
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--##############################################################################
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-- Copyright (C) 2011 Jose A. Ruiz
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-- Copyright (C) 2011 Jose A. Ruiz
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--
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--
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| Line 133... |
Line 134... |
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-- Synchronization FF chain for asynchronous reset input
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-- Synchronization FF chain for asynchronous reset input
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signal reset_sync : std_logic_vector(3 downto 0);
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signal reset_sync : std_logic_vector(3 downto 0);
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|
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-- Reset pushbutton debouncing logic
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-- Reset pushbutton debouncing logic
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subtype t_debouncer is integer range 0 to CLOCK_FREQ;
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subtype t_debouncer is integer range 0 to CLOCK_FREQ*4;
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constant DEBOUNCING_DELAY : t_debouncer := 500;
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constant DEBOUNCING_DELAY : t_debouncer := 1500;
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signal debouncing_counter : t_debouncer := (CLOCK_FREQ/1000) * DEBOUNCING_DELAY;
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signal debouncing_counter : t_debouncer := (CLOCK_FREQ/1000) * DEBOUNCING_DELAY;
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|
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-- Quad 7-segment display (non multiplexed) & LEDS
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-- Quad 7-segment display (non multiplexed) & LEDS
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signal display_data : std_logic_vector(15 downto 0);
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signal display_data : std_logic_vector(15 downto 0);
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signal reg_gleds : std_logic_vector(7 downto 0);
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signal reg_gleds : std_logic_vector(7 downto 0);
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| Line 223... |
Line 224... |
|
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begin
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begin
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|
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mpu: entity work.mips_soc
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mpu: entity work.mips_soc
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generic map (
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generic map (
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OBJ_CODE => obj_code,
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OBJECT_CODE => obj_code,
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BOOT_BRAM_SIZE => work.obj_code_pkg.BRAM_SIZE,
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CLOCK_FREQ => CLOCK_FREQ,
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CLOCK_FREQ => CLOCK_FREQ,
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SRAM_ADDR_SIZE => SRAM_ADDR_SIZE
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SRAM_ADDR_SIZE => SRAM_ADDR_SIZE
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)
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)
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port map (
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port map (
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interrupt => "00000000",
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interrupt => "00000000",
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| Line 361... |
Line 363... |
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--##############################################################################
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--##############################################################################
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-- RESET, CLOCK
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-- RESET, CLOCK
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--##############################################################################
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--##############################################################################
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|
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-- Use button 3 as reset
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-- This FF chain only prevents metastability trouble, it does not help with
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-- This FF chain only prevents metastability trouble, it does not help with
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-- switching bounces.
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-- switching bounces.
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-- (NOTE: the anti-metastability logic is probably not needed when we include
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-- (NOTE: the anti-metastability logic is probably not needed when we include
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-- the debouncing logic)
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-- the debouncing logic)
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reset_synchronization:
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reset_synchronization:
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process(clk)
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process(clk)
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begin
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begin
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if clk'event and clk='1' then
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if clk'event and clk='1' then
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reset_sync(3) <= not buttons(2);
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reset_sync(3) <= not switches(9);
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reset_sync(2) <= reset_sync(3);
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reset_sync(2) <= reset_sync(3);
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reset_sync(1) <= reset_sync(2);
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reset_sync(1) <= reset_sync(2);
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reset_sync(0) <= reset_sync(1);
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reset_sync(0) <= reset_sync(1);
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end if;
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end if;
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end process reset_synchronization;
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end process reset_synchronization;
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