234 lines
8.5 KiB
VHDL
234 lines
8.5 KiB
VHDL
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library ieee;
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use ieee.std_logic_1164.all;
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entity controller is
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port(
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clk : in std_logic;
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reset_n : in std_logic;
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-- instruction opcode
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op : in std_logic_vector(5 downto 0);
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opx : in std_logic_vector(5 downto 0);
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-- activates branch condition
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branch_op : out std_logic;
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-- immediate value sign extention
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imm_signed : out std_logic;
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-- instruction register enable
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ir_en : out std_logic;
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-- PC control signals
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pc_add_imm : out std_logic;
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pc_en : out std_logic;
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pc_sel_a : out std_logic;
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pc_sel_imm : out std_logic;
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-- register file enable
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rf_wren : out std_logic;
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-- multiplexers selections
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sel_addr : out std_logic;
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sel_b : out std_logic;
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sel_mem : out std_logic;
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sel_pc : out std_logic;
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sel_ra : out std_logic;
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sel_rC : out std_logic;
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-- write memory output
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read : out std_logic;
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write : out std_logic;
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-- alu op
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op_alu : out std_logic_vector(5 downto 0)
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);
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end controller;
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architecture synth of controller is
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type state is (FETCH1, FETCH2, DECODE, R_OP, STORE, BREAK, LOAD1, I_OP, LOAD2, BRANCH, CALL,CALLR, JMP, JMPI, UI_OP, RI_OP);
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signal s_cur : state;
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signal s_next : state;
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begin
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--FSM masuta controls
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fsm_ctrl : process(clk, reset_n) is
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begin
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if(reset_n = '0') then
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s_cur <= FETCH1;
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elsif(rising_edge(clk)) then
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s_cur <= s_next;
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end if;
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end process;
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--control states
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s_next <= FETCH2 when s_cur = FETCH1 else
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DECODE when s_cur = FETCH2 else
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BREAK when s_cur = BREAK else
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LOAD2 when s_cur = LOAD1 else
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FETCH1 when (s_cur = LOAD2 or s_cur = STORE or
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s_cur = R_OP or s_cur = I_OP or s_cur = RI_OP or s_cur = UI_OP or
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s_cur = BRANCH or s_cur = CALL or s_cur = CALLR or s_cur = JMP or s_cur = JMPI) else
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R_OP when (s_cur = DECODE and op = "111010" and (opx = "011011" or --srl
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opx = "110001" or --add
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opx = "111001" or --sub
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opx = "001000" or --cmple
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opx = "010000" or --cmpgt
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opx = "000110" or --nor
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opx = "001110" or --and
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opx = "010110" or --or
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opx = "011110" or --xnor
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opx = "010011" or --sll
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opx = "111011" or --sra
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opx = "011000" or --cmpne
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opx = "100000" or --cmpeq
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opx = "101000" or --cmpleu
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opx = "110000" or --cmpgtu
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opx = "000011" or --rol
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opx = "001011") --ror
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) else
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I_OP when (s_cur = DECODE and (op = "000100" or --addi
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op = "001000" or --cmplei
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op = "010000" or --cmpgti
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op = "011000" or --cmpnei
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op = "100000") --cmpeqi
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-- op = "001010") --????????????????????????????????????????
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) else
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UI_OP when (s_cur = DECODE and (op = "001100" or --andi
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op = "010100" or --ori
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op = "011100" or --xnori
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op = "101000" or --cmpleui
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op = "110000") --cmpgtui
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) else
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RI_OP when (s_cur = DECODE and op = "111010" and (opx = "010010" or --slli
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opx = "011010" or --srli
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opx = "111010" or --srai
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opx = "000010") --roli
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) else
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LOAD1 when (s_cur = DECODE and op = "010111") else --ldw
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STORE when (s_cur = DECODE and op = "010101") else --stw
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BRANCH when (s_cur = DECODE and (op = "000110" or --br
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op = "001110" or --ble
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op = "010110" or --bgt
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op = "011110" or --bne
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op = "100110" or --beq
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op = "101110" or --bleu
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op = "110110") --bgtu
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) else
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CALL when (s_cur = DECODE and op = "000000") else --call
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CALLR when (s_cur = DECODE and opx = "011101") else --callr
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JMP when (s_cur = DECODE and (opx = "001101" or --jmp
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opx = "000101") --ret
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) else
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JMPI when (s_cur = DECODE and op = "000001") else --jmpi
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BREAK when (s_cur = DECODE and op = "111010" and opx = "110100"); --break
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--====== All state handlers =======--
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pc_add_imm <= '1' when (s_cur = BRANCH) else '0';
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pc_sel_a <= '1' when (s_cur = JMP or s_cur = CALLR) else'0';
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pc_sel_imm <= '1' when (s_cur = CALL or s_cur = JMPI) else '0';
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sel_pc <= '1' when s_cur = CALL or s_cur = CALLR else '0';
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branch_op <= '1' when s_cur = BRANCH else '0';
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pc_en <= '1' when (s_cur = FETCH1 or s_cur = CALL or s_cur = CALLR or s_cur = JMP or s_cur = JMPI) else '0';
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read <= '1' when (s_cur = FETCH1 or
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s_cur = LOAD1) else '0';
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write <= '1' when (s_cur = STORE) else '0';
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ir_en <= '1' when (s_cur = FETCH2) else '0';
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rf_wren <= '1' when (s_cur = R_OP or
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s_cur = RI_OP or
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s_cur = I_OP or
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s_cur = UI_OP or
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s_cur = CALL or
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s_cur = CALLR or
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s_cur = LOAD2) else '0';
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sel_rC <= '1' when (s_cur = R_OP or s_cur = RI_OP or s_cur = CALLR) else '0';
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sel_b <= '1' when (s_cur = R_OP or s_cur = BRANCH) else '0';
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sel_ra <= '1' when (s_cur = CALL or s_cur = CALLR) else '0';
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sel_addr <= '1' when (s_cur = LOAD1 or
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s_cur = STORE) else '0';
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sel_mem <= '1' when s_cur = LOAD2 else '0';
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imm_signed <= '1' when (s_cur = I_OP or
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s_cur = LOAD1 or
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s_cur = STORE) else '0';
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-- Alu state
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op_alu <= "000000" when (op = "000100" or --addi
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op = "010111" or --ldw
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op = "010101" --stw
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) else --rA + (signed)imm
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"000110" when (op = "111010" and opx = "110001" --add
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) else --rA + rB
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"001111" when (op = "111010" and opx = "111001" --sub
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) else --rA - rB
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"100001" when (op = "111010" and opx = "001110" --and
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) else --rA & rB
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"100001" when (op = "001100" --andi
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) else --rA & (unsigned)imm
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"100010" when (op = "111010" and opx = "010110" --or
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) else --rA | rB
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"101010" when (op = "010100" --ori
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) else --rA | (unsigned)imm
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"100011" when (op = "111010" and opx = "011110" --xnor
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) else --rA xnor rB
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"100011" when (op = "011100" --xnori
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) else --rA xnor (unsigned)imm
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"100000" when (op = "111010" and opx = "000110" --nor
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) else --rA nor rB
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"111011" when (op = "111010" and opx = "011010" --srli
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) else --(unsigned)rA >> imm
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"110011" when (op = "111010" and opx = "011011" --srl
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) else --(unsigned)rA >> rB
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"111010" when (op = "111010" and opx = "010010" --slli
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) else --(unsigned)rA << imm
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"110010" when (op = "111010" and opx = "010011" --sll
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) else --(unsigned)rA << rB
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"111111" when (op = "111010" and opx = "111010" --srai
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) else --(signed)rA >> imm
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"110111" when (op = "111010" and opx = "111011" --sra
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) else --(signed)rA >> rB
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"011001" when (op = "001110" or --ble
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op = "001000" or --cmplei
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(op = "111010" and opx = "001000") --cmple
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) else -- rA <= rB , rA <= (signed)imm
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"011010" when (op = "010110" or --bgt
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op = "010000" or --cmpgti
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(op = "111010" and opx = "010000") --cmpgt
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) else -- rA > rB , rA > (signed)imm
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"011011" when (op = "011110" or --bne
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op = "011000" or --cmpnei
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(op = "111010" and opx = "011000") --cmpne
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) else -- rA != rB , rA != (signed)imm
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"011100" when (op = "100110" or --beq
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op = "100000" or --cmpeqi
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(op = "111010" and opx = "100000") --cmpeq
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) else --rA = rB , rA = (signed)imm
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"011101" when (op = "101110" or --bleu
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op = "101000" or --cmpleui
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(op = "111010" and opx = "101000") --cmpleu
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) else --(unsigned)rA <= (unsigned)rB , (unsigned)rA <= (unsigned)imm
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"011110" when (op = "110110" or --bgtu
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op = "110000" or --cmpgtui
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(op = "111010" and opx = "110000") --cmpgtu
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) else --(unsigned)rA > (unsigned)rB , (unsigned)rA > (unsigned)imm
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"110000" when (op = "111010" and opx = "000011" --rol
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) else --rA rol rB
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"111000" when (op = "111010" and opx = "000010" --roli
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) else --rA rol imm
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"110001" when (op = "111010" and opx = "001011" --ror
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) else --rA ror rB
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"000000"; --DEFAULT
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end synth;
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