| Line 19... |
Line 19... |
-- along with this program. If not, see <http://www.gnu.org/licenses/>. --
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-- along with this program. If not, see <http://www.gnu.org/licenses/>. --
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-- --
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-- --
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------------------------------------------------------------------------------
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------------------------------------------------------------------------------
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------------------------------------------------------------------------------
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------------------------------------------------------------------------------
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-- 04.11.2019 TG insert RTE from TH
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-- 03.11.2019 TG insert TrapV from TH
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-- 03.11.2019 TG insert TrapV from TH
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-- 03.11.2019 TG bugfix MUL 64Bit
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-- 03.11.2019 TG bugfix MUL 64Bit
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-- 03.11.2019 TG rework barrel shifter - some other tweaks
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-- 03.11.2019 TG rework barrel shifter - some other tweaks
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-- 02.11.2019 TG bugfig N-Flag and Z-Flag for DIV
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-- 02.11.2019 TG bugfig N-Flag and Z-Flag for DIV
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-- 30.10.2019 TG bugfix RTR in 68020-mode
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-- 30.10.2019 TG bugfix RTR in 68020-mode
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| Line 694... |
Line 695... |
ELSIF setstate="10" AND write_back='1' THEN
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ELSIF setstate="10" AND write_back='1' THEN
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-- elsif setstate = "10" and write_back = '1' and next_micro_state = idle then --???
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-- elsif setstate = "10" and write_back = '1' and next_micro_state = idle then --???
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exec_write_back <= '1';
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exec_write_back <= '1';
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END IF;
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END IF;
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IF exec(save_OP2)='1' THEN
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IF exec(hold_OP2)='1' THEN
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use_direct_data <= '1';
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use_direct_data <= '1';
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END IF;
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END IF;
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IF set_direct_data='1' THEN
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IF set_direct_data='1' THEN
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direct_data <= '1';
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direct_data <= '1';
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use_direct_data <= '1';
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use_direct_data <= '1';
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| Line 1334... |
Line 1335... |
-- decode opcode
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-- decode opcode
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-----------------------------------------------------------------------------
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-----------------------------------------------------------------------------
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PROCESS (clk, cpu, OP1out, OP2out, opcode, exe_condition, nextpass, micro_state, decodeOPC, state, setexecOPC, Flags, FlagsSR, direct_data, build_logical,
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PROCESS (clk, cpu, OP1out, OP2out, opcode, exe_condition, nextpass, micro_state, decodeOPC, state, setexecOPC, Flags, FlagsSR, direct_data, build_logical,
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build_bcd, set_Z_error, trapd, movem_run, last_data_read, set, set_V_Flag, z_error, trap_trace, trap_interrupt,
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build_bcd, set_Z_error, trapd, movem_run, last_data_read, set, set_V_Flag, z_error, trap_trace, trap_interrupt,
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SVmode, preSVmode, stop, long_done, ea_only, setstate, execOPC, exec_write_back, exe_datatype,
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SVmode, preSVmode, stop, long_done, ea_only, setstate, execOPC, exec_write_back, exe_datatype,
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datatype, interrupt, c_out, trapmake, rot_cnt, brief, addr, trap_trapv,
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datatype, interrupt, c_out, trapmake, rot_cnt, brief, addr, trap_trapv, last_data_in,
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long_start, set_datatype, sndOPC, set_exec, exec, ea_build_now, reg_QA, reg_QB, make_berr, trap_berr)
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long_start, set_datatype, sndOPC, set_exec, exec, ea_build_now, reg_QA, reg_QB, make_berr, trap_berr)
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BEGIN
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BEGIN
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TG68_PC_brw <= '0';
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TG68_PC_brw <= '0';
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setstate <= "00";
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setstate <= "00";
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Regwrena_now <= '0';
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Regwrena_now <= '0';
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| Line 3181... |
Line 3182... |
setstate <= "11";
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setstate <= "11";
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datatype <= "01";
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datatype <= "01";
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writeSR <= '1';
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writeSR <= '1';
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next_micro_state <= trap3;
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next_micro_state <= trap3;
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-- return from exception - RTE
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-- fetch PC and status register from stack
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-- 010+ fetches another word containing
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-- the 12 bit vector offset and the
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-- frame format. If the frame format is
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-- 2 another two words have to be taken
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-- from the stack
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WHEN rte1 => -- RTE
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WHEN rte1 => -- RTE
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datatype <= "10";
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datatype <= "10";
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setstate <= "10";
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setstate <= "10";
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set(postadd) <= '1';
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set(postadd) <= '1';
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setstackaddr <= '1';
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setstackaddr <= '1';
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| Line 3196... |
Line 3204... |
next_micro_state <= rte2;
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next_micro_state <= rte2;
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WHEN rte2 => -- RTE
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WHEN rte2 => -- RTE
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datatype <= "01";
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datatype <= "01";
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set(update_FC) <= '1';
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set(update_FC) <= '1';
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IF (VBR_Stackframe=1 OR (cpu(0)='1' AND VBR_Stackframe=2)) AND opcode(2)='0' THEN
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IF (VBR_Stackframe=1 OR (cpu(0)='1' AND VBR_Stackframe=2)) AND opcode(2)='0' THEN
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-- 010+ reads another word
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setstate <= "10";
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setstate <= "10";
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set(postadd) <= '1';
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set(postadd) <= '1';
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setstackaddr <= '1';
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setstackaddr <= '1';
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next_micro_state <= rte3;
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next_micro_state <= rte3;
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ELSE
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ELSE
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next_micro_state <= nop;
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next_micro_state <= nop;
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END IF;
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END IF;
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WHEN rte3 => -- RTE
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-- WHEN rte3 => -- RTE
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-- next_micro_state <= nop;
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---- set(update_FC) <= '1';
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-- paste and copy form TH ---------
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when rte3 => -- RTE
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setstate <= "01"; -- idle state to wait
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-- for input data to
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-- arrive
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next_micro_state <= rte4;
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WHEN rte4 => -- RTE
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-- check for stack frame format #2
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if last_data_in(15 downto 12)="0010" then
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-- read another 32 bits in this case
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setstate <= "10"; -- read
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datatype <= "10"; -- long word
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set(postadd) <= '1';
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setstackaddr <= '1';
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next_micro_state <= rte5;
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else
|
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datatype <= "01";
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next_micro_state <= nop;
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next_micro_state <= nop;
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-- set(update_FC) <= '1';
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end if;
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WHEN rte5 => -- RTE
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next_micro_state <= nop;
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-------------------------------------
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|
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WHEN rtd1 => -- RTD
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WHEN rtd1 => -- RTD
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next_micro_state <= rtd2;
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next_micro_state <= rtd2;
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WHEN rtd2 => -- RTD
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WHEN rtd2 => -- RTD
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setstackaddr <= '1';
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setstackaddr <= '1';
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| Line 3297... |
Line 3327... |
ELSE
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ELSE
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next_micro_state <= mul2;
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next_micro_state <= mul2;
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END IF;
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END IF;
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WHEN mul_end1 => -- mulu
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WHEN mul_end1 => -- mulu
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IF opcode(15)='0' THEN
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IF opcode(15)='0' THEN
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set(save_OP2) <= '1';
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set(hold_OP2) <= '1';
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END IF;
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END IF;
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datatype <= "10";
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datatype <= "10";
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set(opcMULU) <= '1';
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set(opcMULU) <= '1';
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IF opcode(15)='0' AND (MUL_Mode=1 OR MUL_Mode=2) THEN
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IF opcode(15)='0' AND (MUL_Mode=1 OR MUL_Mode=2) THEN
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dest_2ndHbits <= '1';
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dest_2ndHbits <= '1';
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