| Line 68... |
Line 68... |
-- access control --
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-- access control --
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signal acc_en : std_ulogic; -- module access enable
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signal acc_en : std_ulogic; -- module access enable
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signal addr : std_ulogic_vector(31 downto 0); -- access address
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signal addr : std_ulogic_vector(31 downto 0); -- access address
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-- accessible regs --
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-- accessible regs --
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signal din : std_ulogic_vector(31 downto 0); -- r/w
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signal din : std_ulogic_vector(31 downto 0); -- r/-
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signal dout : std_ulogic_vector(31 downto 0); -- r/w
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signal dout : std_ulogic_vector(31 downto 0); -- r/w
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signal irq_en : std_ulogic_vector(31 downto 0); -- -/w, uses the same address as data_in
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-- misc --
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-- misc --
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signal in_buf : std_ulogic_vector(31 downto 0);
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signal in_buf : std_ulogic_vector(31 downto 0);
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begin
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begin
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| Line 90... |
Line 91... |
begin
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begin
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if rising_edge(clk_i) then
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if rising_edge(clk_i) then
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ack_o <= acc_en and (rden_i or wren_i);
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ack_o <= acc_en and (rden_i or wren_i);
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-- write access --
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-- write access --
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if ((acc_en and wren_i) = '1') then
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if ((acc_en and wren_i) = '1') then
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if (addr = gpio_out_addr_c) then
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if (addr = gpio_in_addr_c) then
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dout <= data_i;
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irq_en <= data_i; -- pin change IRQ enable
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else -- gpio_out_addr_c
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dout <= data_i; -- data output port
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end if;
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end if;
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end if;
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end if;
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-- read access --
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-- read access --
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data_o <= (others => '0');
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data_o <= (others => '0');
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if ((acc_en and rden_i) = '1') then
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if ((acc_en and rden_i) = '1') then
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if (addr = gpio_in_addr_c) then
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if (addr = gpio_in_addr_c) then
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data_o <= din;
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data_o <= din; -- data input port
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else -- gpio_out_addr_c
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else -- gpio_out_addr_c
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data_o <= dout;
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data_o <= dout; -- data output port
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end if;
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end if;
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end if;
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end if;
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end if;
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end if;
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end process rw_access;
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end process rw_access;
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| Line 119... |
Line 122... |
if rising_edge(clk_i) then
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if rising_edge(clk_i) then
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-- input synchronizer --
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-- input synchronizer --
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in_buf <= gpio_i;
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in_buf <= gpio_i;
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din <= in_buf;
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din <= in_buf;
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-- IRQ --
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-- IRQ --
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irq_o <= or_all_f(in_buf xor din); -- any transition triggers an interrupt
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irq_o <= or_all_f((in_buf xor din) and irq_en); -- any enabled pin transition triggers an interrupt
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end if;
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end if;
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end process irq_detector;
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end process irq_detector;
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end neorv32_gpio_rtl;
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end neorv32_gpio_rtl;
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