| Line 222... |
Line 222... |
-- from being set outside of an ISR. The
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-- from being set outside of an ISR. The
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-- Default_Int_Flag setting allows the I bit to
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-- Default_Int_Flag setting allows the I bit to
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-- start set so that initialization code can run,
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-- start set so that initialization code can run,
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-- but not be hijacked later to corrupt any memory
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-- but not be hijacked later to corrupt any memory
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-- write protection later.
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-- write protection later.
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-- Seth Henry 05/21/20 Supervisor_Mode now protects the interrupt mask
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-- and stack pointer as well.
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library ieee;
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library ieee;
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use ieee.std_logic_1164.all;
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use ieee.std_logic_1164.all;
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use ieee.std_logic_unsigned.all;
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use ieee.std_logic_unsigned.all;
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use ieee.std_logic_arith.all;
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use ieee.std_logic_arith.all;
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| Line 315... |
Line 317... |
signal DP_Ctrl : DATA_CTRL_TYPE;
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signal DP_Ctrl : DATA_CTRL_TYPE;
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signal INT_Ctrl : INT_CTRL_TYPE;
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signal INT_Ctrl : INT_CTRL_TYPE;
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signal Ack_D, Ack_Q, Ack_Q1: std_logic := '0';
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signal Ack_D, Ack_Q, Ack_Q1: std_logic := '0';
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signal Int_Req, Int_Ack : std_logic := '0';
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signal Int_Req, Int_Ack : std_logic := '0';
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signal Set_Mask : std_logic := '0';
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signal Int_Mask : DATA_TYPE := x"00";
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signal Int_Mask : DATA_TYPE := x"00";
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signal ISR_Addr : ADDRESS_TYPE := x"0000";
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signal ISR_Addr : ADDRESS_TYPE := x"0000";
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signal i_Ints : INTERRUPT_BUNDLE := x"00";
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signal i_Ints : INTERRUPT_BUNDLE := x"00";
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signal Pending : INTERRUPT_BUNDLE := x"00";
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signal Pending : INTERRUPT_BUNDLE := x"00";
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signal Wait_for_FSM : std_logic := '0';
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signal Wait_for_FSM : std_logic := '0';
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| Line 987... |
Line 990... |
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Int_Req <= '0';
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Int_Req <= '0';
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Pending <= x"00";
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Pending <= x"00";
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Wait_for_FSM <= '0';
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Wait_for_FSM <= '0';
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Wait_for_ISR <= '0';
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Wait_for_ISR <= '0';
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Set_Mask <= '0';
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if( Enable_NMI )then
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if( Enable_NMI )then
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Int_Mask <= Default_Interrupt_Mask(7 downto 1) & '1';
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Int_Mask <= Default_Interrupt_Mask(7 downto 1) & '1';
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else
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else
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Int_Mask <= Default_Interrupt_Mask;
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Int_Mask <= Default_Interrupt_Mask;
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end if;
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end if;
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| Line 1100... |
Line 1104... |
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when SP_CLR =>
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when SP_CLR =>
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Stack_Ptr <= Stack_Start_Addr;
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Stack_Ptr <= Stack_Start_Addr;
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when SP_SET =>
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when SP_SET =>
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if( Supervisor_Mode )then
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if( Flags(PSR_I) = '1' )then
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Stack_Ptr <= Regfile(1) & Regfile(0);
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Stack_Ptr <= Regfile(1) & Regfile(0);
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end if;
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else
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Stack_Ptr <= Regfile(1) & Regfile(0);
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end if;
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when SP_POP =>
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when SP_POP =>
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Stack_Ptr <= Stack_Ptr + 1;
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Stack_Ptr <= Stack_Ptr + 1;
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when SP_PUSH =>
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when SP_PUSH =>
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| Line 1116... |
Line 1126... |
end case;
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end case;
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-------------------------------------------------------------------------------
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-------------------------------------------------------------------------------
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-- Interrupt Controller
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-- Interrupt Controller
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-------------------------------------------------------------------------------
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-------------------------------------------------------------------------------
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-- If Supervisor_Mode is set, restrict the SMSK instruction such that it
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-- requires the I bit to be set.
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if( Supervisor_Mode )then
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Set_Mask <= INT_Ctrl.Mask_Set and Flags(PSR_I);
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else
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Set_Mask <= INT_Ctrl.Mask_Set;
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end if;
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-- The interrupt control mask is always sourced out of R0
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-- The interrupt control mask is always sourced out of R0
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if( INT_Ctrl.Mask_Set = '1' )then
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if( Set_Mask = '1' )then
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if( Enable_NMI )then
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if( Enable_NMI )then
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Int_Mask <= Regfile(conv_integer(ACCUM))(7 downto 1) & '1';
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Int_Mask <= Regfile(conv_integer(ACCUM))(7 downto 1) & '1';
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else
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else
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Int_Mask <= Regfile(conv_integer(ACCUM));
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Int_Mask <= Regfile(conv_integer(ACCUM));
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end if;
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end if;
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