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[/] [avr_hp/] [trunk/] [rtl/] [rtl_orig/] [pm_fetch_dec.vhd] - Blame information for rev 2

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--************************************************************************************************
--  PM_FETCH_DEC(internal module) for AVR core
--      Version 2.6! (Special version for the JTAG OCD)
--  Designed by Ruslan Lepetenok 14.11.2001
--  Modified 31.05.06
--  Modification:
--  Registered ramre/ramwe outputs
--  cpu_busy logic modified(affects RCALL/ICALL/CALL instruction interract with interrupt)
--  SLEEP and CLRWDT instructions support was added
--  V-flag bug fixed (AND/ANDI/OR/ORI/EOR)
--  V-flag bug fixed (ADIW/SBIW)
--  Unused outputs(sreg_bit_num[2..0],idc_sbi_out,idc_cbi_out,idc_bld_out) were removed.
--  Output alu_data_d_in[7..0] was removed.
--  Gloabal clock enable(cp2en) was added  
--  cpu_busy(push/pop) + irq bug was fixed 14.07.05
--  BRXX+IRQ interaction was modified -> cpu_busy
--  LDS/STS now requires only two cycles for execution (13.01.06 -> last modificatioon)
--************************************************************************************************
 
library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.std_logic_unsigned.all;
 
use WORK.AVRuCPackage.all;
 
entity pm_fetch_dec is port(
                              -- Clock and reset
                              cp2              : in  std_logic;
                                                          cp2en            : in  std_logic;
                              ireset           : in  std_logic;
                                                          -- JTAG OCD support
                                                          valid_instr      : out  std_logic;
                                                      insert_nop       : in   std_logic;
                                                      block_irq        : in   std_logic;
                                                      change_flow      : out  std_logic;
                                                          -- Program memory
                              pc               : out std_logic_vector (15 downto 0);
                              inst             : in  std_logic_vector (15 downto 0);
                              -- I/O control
                              adr              : out std_logic_vector (5 downto 0);
                              iore             : out std_logic;
                              iowe             : out std_logic;
                              -- Data memory control
                              ramadr           : out std_logic_vector (15 downto 0);
                              ramre            : out std_logic;
                              ramwe            : out std_logic;
                              cpuwait          : in  std_logic;
                                                          -- Data paths
                              dbusin           : in  std_logic_vector (7 downto 0);
                              dbusout          : out std_logic_vector (7 downto 0);
                              dbusout_int_route : out std_logic_vector (7 downto 0);
                              -- Interrupt
                              irqlines         : in  std_logic_vector (22 downto 0);
                              irqack           : out std_logic;
                              irqackad         : out std_logic_vector(4 downto 0);
                                                      --Sleep 
                              sleepi           : out std_logic;
                              irqok                : out std_logic;
                              --Watchdog
                              wdri                 : out std_logic;
                                                          -- ALU interface(Data inputs)
                              alu_data_r_in    : out std_logic_vector(7 downto 0);
                                                          -- ALU interface(Instruction inputs)
                                                          idc_add_out      : out std_logic;
                              idc_adc_out      : out std_logic;
                              idc_adiw_out     : out std_logic;
                              idc_sub_out      : out std_logic;
                              idc_subi_out     : out std_logic;
                              idc_sbc_out      : out std_logic;
                              idc_sbci_out     : out std_logic;
                              idc_sbiw_out     : out std_logic;
 
                              adiw_st_out      : out std_logic;
                              sbiw_st_out      : out std_logic;
 
                              idc_and_out      : out std_logic;
                              idc_andi_out     : out std_logic;
                              idc_or_out       : out std_logic;
                              idc_ori_out      : out std_logic;
                              idc_eor_out      : out std_logic;
                              idc_com_out      : out std_logic;
                              idc_neg_out      : out std_logic;
 
                              idc_inc_out      : out std_logic;
                              idc_dec_out      : out std_logic;
 
                              idc_cp_out       : out std_logic;
                              idc_cpc_out      : out std_logic;
                              idc_cpi_out      : out std_logic;
                              idc_cpse_out     : out std_logic;
 
                              idc_lsr_out      : out std_logic;
                              idc_ror_out      : out std_logic;
                              idc_asr_out      : out std_logic;
                              idc_swap_out     : out std_logic;
 
                               -- ALU interface(Data output)
                               alu_data_out    : in std_logic_vector(7 downto 0);
 
                               -- ALU interface(Flag outputs)
                               alu_c_flag_out  : in std_logic;
                               alu_z_flag_out  : in std_logic;
                               alu_n_flag_out  : in std_logic;
                               alu_v_flag_out  : in std_logic;
                               alu_s_flag_out  : in std_logic;
                               alu_h_flag_out  : in std_logic;
 
                                                           -- General purpose register file interface
                               reg_rd_in       : out std_logic_vector  (7 downto 0);
                               reg_rd_out      : in  std_logic_vector  (7 downto 0);
                               reg_rd_out_int  : in std_logic_vector(7 downto 0);
                               reg_rd_adr      : out std_logic_vector  (4 downto 0);
                               reg_rd_adr_int      : out std_logic_vector  (4 downto 0);
                               reg_rr_out      : in  std_logic_vector  (7 downto 0);
                               reg_rr_adr      : out std_logic_vector  (4 downto 0);
                               reg_rd_wr       : out std_logic;
 
                               post_inc        : out std_logic;                       -- POST INCREMENT FOR LD/ST INSTRUCTIONS
                               pre_dec         : out std_logic;                        -- PRE DECREMENT FOR LD/ST INSTRUCTIONS
                               reg_h_wr        : out std_logic;
                               reg_h_out       : in  std_logic_vector (15 downto 0);
                               reg_h_adr       : out std_logic_vector (2 downto 0);    -- x,y,z
                                       reg_z_out       : in  std_logic_vector (15 downto 0);  -- OUTPUT OF R31:R30 FOR LPM/ELPM/IJMP INSTRUCTIONS
 
                               -- I/O register file interface
                               sreg_fl_in      : out std_logic_vector(7 downto 0);
                               globint         : in  std_logic; -- SREG I flag
 
                               sreg_fl_wr_en   : out std_logic_vector(7 downto 0);   --FLAGS WRITE ENABLE SIGNALS       
 
                               spl_out         : in  std_logic_vector(7 downto 0);
                               sph_out         : in  std_logic_vector(7 downto 0);
                               sp_ndown_up     : out std_logic; -- DIRECTION OF CHANGING OF STACK POINTER SPH:SPL 0->UP(+) 1->DOWN(-)
                               sp_en           : out std_logic; -- WRITE ENABLE(COUNT ENABLE) FOR SPH AND SPL REGISTERS
 
                               rampz_out       : in  std_logic_vector(7 downto 0);
 
                                                           -- Bit processor interface
                               bit_num_r_io    : out std_logic_vector (2 downto 0); -- BIT NUMBER FOR CBI/SBI/BLD/BST/SBRS/SBRC/SBIC/SBIS INSTRUCTIONS
                               bitpr_io_out    : in  std_logic_vector(7 downto 0);  -- SBI/CBI OUT        
                               branch          : out std_logic_vector (2 downto 0); -- NUMBER (0..7) OF BRANCH CONDITION FOR BRBS/BRBC INSTRUCTION
                               bit_pr_sreg_out : in  std_logic_vector(7 downto 0);  -- BCLR/BSET/BST(T-FLAG ONLY)             
                               bld_op_out      : in  std_logic_vector(7 downto 0);  -- BLD OUT (T FLAG)
                               bit_test_op_out : in  std_logic;                     -- OUTPUT OF SBIC/SBIS/SBRS/SBRC
 
                               sbi_st_out      : out std_logic;
                               cbi_st_out      : out std_logic;
 
                               idc_bst_out     : out std_logic;
                               idc_bset_out    : out std_logic;
                               idc_bclr_out    : out std_logic;
 
                               idc_sbic_out    : out std_logic;
                               idc_sbis_out    : out std_logic;
 
                               idc_sbrs_out    : out std_logic;
                               idc_sbrc_out    : out std_logic;
 
                               idc_brbs_out    : out std_logic;
                               idc_brbc_out    : out std_logic;
 
                               idc_reti_out    : out std_logic);
end pm_fetch_dec;
 
architecture RTL of pm_fetch_dec is
 
-- COPIES OF OUTPUTS
signal ramadr_reg_in  : std_logic_vector(15 downto 0); -- INPUT OF THE ADDRESS REGISTER
signal ramadr_reg_en  : std_logic;                     -- ADRESS REGISTER CLOCK ENABLE SIGNAL
 
signal irqack_int     : std_logic;
signal irqackad_int   : std_logic_vector(irqackad'range);
 
-- ####################################################
-- INTERNAL SIGNALS
-- ####################################################
 
-- NEW SIGNALS
signal   two_word_inst       : std_logic;                    -- CALL/JMP/STS/LDS INSTRUCTION INDICATOR
 
signal   ram_adr_int         : std_logic_vector (15 downto 0);
constant const_ram_to_reg    : std_logic_vector := "00000000000";  -- LD/LDS/LDD/ST/STS/STD ADDRESSING GENERAL PURPOSE REGISTER (R0-R31) 0x00..0x19
constant const_ram_to_io_a   : std_logic_vector := "00000000001";  -- LD/LDS/LDD/ST/STS/STD ADDRESSING GENERAL I/O PORT 0x20 0x3F 
constant const_ram_to_io_b   : std_logic_vector := "00000000010";  -- LD/LDS/LDD/ST/STS/STD ADDRESSING GENERAL I/O PORT 0x20 0x3F 
 
-- LD/LDD/ST/STD SIGNALS
signal adiw_sbiw_encoder_out : std_logic_vector (4 downto 0);
signal adiw_sbiw_encoder_mux_out : std_logic_vector (4 downto 0);
 
 
-- PROGRAM COUNTER SIGNALS
signal program_counter_tmp : std_logic_vector (15 downto 0); -- TO STORE PC DURING LPM/ELPM INSTRUCTIONS
signal program_counter     : std_logic_vector (15 downto 0);
signal program_counter_in  : std_logic_vector (15 downto 0);
signal program_counter_high_fr  : std_logic_vector (7 downto 0); -- TO STORE PC FOR CALL,IRQ,RCALL,ICALL
 
signal pc_low       : std_logic_vector (7 downto 0);
signal pc_high      : std_logic_vector (7 downto 0);
 
 
signal pc_low_en       : std_logic;
signal pc_high_en      : std_logic;
 
signal offset_brbx     : std_logic_vector (15 downto 0);    -- OFFSET FOR BRCS/BRCC   INSTRUCTION  !!CHECKED
signal offset_rxx      : std_logic_vector (15 downto 0);    -- OFFSET FOR RJMP/RCALL  INSTRUCTION  !!CHECKED
 
signal pa15_pm         : std_logic; -- ADDRESS LINE 15 FOR LPM/ELPM INSTRUCTIONS ('0' FOR LPM,RAMPZ(0) FOR ELPM) 
 
signal alu_reg_wr      : std_logic; -- ALU INSTRUCTIONS PRODUCING WRITE TO THE GENERAL PURPOSE REGISTER FILE    
 
-- DATA MEMORY,GENERAL PURPOSE REGISTERS AND I/O REGISTERS LOGIC
 
--! IMPORTANT NOTICE : OPERATIONS WHICH USE STACK POINTER (SPH:SPL) CAN NOT ACCCSESS GENERAL
-- PURPOSE REGISTER FILE AND INPUT/OUTPUT REGISTER FILE !
-- THESE OPERATIONS ARE : RCALL/ICALL/CALL/RET/RETI/PUSH/POP INSTRUCTIONS  AND INTERRUPT 
 
signal reg_file_adr_space  : std_logic; -- ACCSESS TO THE REGISTER FILE
signal io_file_adr_space   : std_logic; -- ACCSESS TO THE I/O FILE
 
-- STATE MACHINES SIGNALS
signal irq_start      : std_logic;
 
signal nirq_st0       : std_logic;
signal irq_st1        : std_logic;
signal irq_st2        : std_logic;
signal irq_st3        : std_logic;
 
signal ncall_st0      : std_logic;
signal call_st1       : std_logic;
signal call_st2       : std_logic;
signal call_st3       : std_logic;
 
signal nrcall_st0     : std_logic;
signal rcall_st1      : std_logic;
signal rcall_st2      : std_logic;
 
signal nicall_st0     : std_logic;
signal icall_st1      : std_logic;
signal icall_st2      : std_logic;
 
signal njmp_st0       : std_logic;
signal jmp_st1        : std_logic;
signal jmp_st2        : std_logic;
 
signal ijmp_st        : std_logic;
 
signal rjmp_st        : std_logic;
 
signal nret_st0       : std_logic;
signal ret_st1        : std_logic;
signal ret_st2        : std_logic;
signal ret_st3        : std_logic;
 
signal nreti_st0      : std_logic;
signal reti_st1       : std_logic;
signal reti_st2       : std_logic;
signal reti_st3       : std_logic;
 
signal brxx_st        : std_logic;  -- BRANCHES
 
signal adiw_st        : std_logic;
signal sbiw_st        : std_logic;
 
signal nskip_inst_st0 : std_logic;
signal skip_inst_st1  : std_logic;
signal skip_inst_st2  : std_logic;  -- ALL SKIP INSTRUCTIONS SBRS/SBRC/SBIS/SBIC/CPSE 
 
signal skip_inst_start  : std_logic;
 
signal nlpm_st0       : std_logic;
signal lpm_st1        : std_logic;
signal lpm_st2        : std_logic;
 
signal nelpm_st0      : std_logic;
signal elpm_st1       : std_logic;
signal elpm_st2       : std_logic;
 
--signal nsts_st0       : std_logic;
--signal sts_st1        : std_logic;
--signal sts_st2        : std_logic;
 
signal sts_st         : std_logic;
 
--signal nlds_st0       : std_logic;
--signal lds_st1        : std_logic;
--signal lds_st2        : std_logic;
 
signal lds_st           : std_logic;
 
signal st_st          : std_logic;
signal ld_st          : std_logic;
 
signal sbi_st         : std_logic;
signal cbi_st         : std_logic;
 
signal push_st        : std_logic;
signal pop_st         : std_logic;
 
-- INTERNAL STATE MACHINES
signal nop_insert_st  : std_logic;
signal cpu_busy       : std_logic;
 
-- INTERNAL COPIES OF OUTPUTS
signal pc_int              : std_logic_vector (15 downto 0);
signal adr_int             : std_logic_vector (5 downto 0);
signal iore_int                    : std_logic;
signal iowe_int            : std_logic;
signal ramadr_int          : std_logic_vector (15 downto 0);
signal ramre_int           : std_logic;
signal ramwe_int           : std_logic;
signal dbusout_int         : std_logic_vector (7 downto 0);
 
-- COMMAND REGISTER
signal instruction_reg      : std_logic_vector (15 downto 0); -- OUTPUT OF THE INSTRUCTION REGISTER
signal instruction_code_reg : std_logic_vector (15 downto 0); -- OUTPUT OF THE INSTRUCTION REGISTER WITH NOP INSERTION
signal instruction_reg_ena  : std_logic;                               -- CLOCK ENABLE
 
 
-- IRQ INTERNAL LOGIC
signal irq_int              : std_logic;
signal irq_vector_adr       : std_logic_vector(15 downto 0);
 
-- INTERRUPT RELATING REGISTERS
signal pc_for_interrupt : std_logic_vector(15 downto 0);
 
-- DATA EXTRACTOR SIGNALS
signal dex_dat8_immed  : std_logic_vector (7 downto 0);  -- IMMEDIATE CONSTANT (DATA) -> ANDI,ORI,SUBI,SBCI,CPI,LDI
signal dex_dat6_immed  : std_logic_vector (5 downto 0);  -- IMMEDIATE CONSTANT (DATA) -> ADIW,SBIW
signal dex_adr12mem_s  : std_logic_vector (11 downto 0); -- RELATIVE ADDRESS (SIGNED) -> RCALL,RJMP
signal dex_adr6port    : std_logic_vector (5 downto 0);  -- I/O PORT ADDRESS -> IN,OUT
signal dex_adr5port    : std_logic_vector (4 downto 0);  -- I/O PORT ADDRESS -> CBI,SBI,SBIC,SBIS
signal dex_adr_disp    : std_logic_vector (5 downto 0);  -- DISPLACEMENT FO ADDDRESS -> STD,LDD
signal dex_condition   : std_logic_vector (2 downto 0);  -- CONDITION -> BRBC,BRBS
signal dex_bitnum_sreg : std_logic_vector (2 downto 0);  -- NUMBER OF BIT IN SREG -> BCLR,BSET
signal dex_adrreg_r    : std_logic_vector (4 downto 0);  -- SOURCE REGISTER ADDRESS -> .......
signal dex_adrreg_d    : std_logic_vector (4 downto 0);  -- DESTINATION REGISTER ADDRESS -> ......
signal dex_bitop_bitnum : std_logic_vector(2 downto 0);  -- NUMBER OF BIT FOR BIT ORIENTEDE OPERATION -> BST/BLD+SBI/CBI+SBIC/SBIS+SBRC/SBRS !! CHECKED
signal dex_brxx_offset : std_logic_vector (6 downto 0);  -- RELATIVE ADDRESS (SIGNED) -> BRBC,BRBS !! CHECKED
signal dex_adiw_sbiw_reg_adr  : std_logic_vector (1 downto 0);  -- ADDRESS OF THE LOW REGISTER FOR ADIW/SBIW INSTRUCTIONS
 
signal dex_adrreg_d_latched : std_logic_vector (4 downto 0);   --  STORE ADDRESS OF DESTINATION REGISTER FOR LDS/STS/POP INSTRUCTIONS
signal gp_reg_tmp           : std_logic_vector (7 downto 0);   --  STORE DATA FROM THE REGISTERS FOR STS,ST INSTRUCTIONS
signal cbi_sbi_io_adr_tmp   : std_logic_vector (4 downto 0);   --  STORE ADDRESS OF I/O PORT FOR CBI/SBI INSTRUCTION
signal cbi_sbi_bit_num_tmp  : std_logic_vector (2 downto 0);   --  STORE ADDRESS OF I/O PORT FOR CBI/SBI INSTRUCTION
 
-- INSTRUCTIONS DECODER SIGNALS
 
signal idc_adc     : std_logic; -- INSTRUCTION ADC
signal idc_add     : std_logic; -- INSTRUCTION ADD
signal idc_adiw    : std_logic; -- INSTRUCTION ADIW
signal idc_and     : std_logic; -- INSTRUCTION AND
signal idc_andi    : std_logic; -- INSTRUCTION ANDI
signal idc_asr     : std_logic; -- INSTRUCTION ASR
 
signal idc_bclr    : std_logic; -- INSTRUCTION BCLR
signal idc_bld     : std_logic; -- INSTRUCTION BLD
signal idc_brbc    : std_logic; -- INSTRUCTION BRBC
signal idc_brbs    : std_logic; -- INSTRUCTION BRBS
signal idc_bset    : std_logic; -- INSTRUCTION BSET
signal idc_bst     : std_logic; -- INSTRUCTION BST
 
signal idc_call    : std_logic; -- INSTRUCTION CALL
signal idc_cbi     : std_logic; -- INSTRUCTION CBI
signal idc_com     : std_logic; -- INSTRUCTION COM
signal idc_cp      : std_logic; -- INSTRUCTION CP
signal idc_cpc     : std_logic; -- INSTRUCTION CPC
signal idc_cpi     : std_logic; -- INSTRUCTION CPI
signal idc_cpse    : std_logic; -- INSTRUCTION CPSE
 
signal idc_dec     : std_logic; -- INSTRUCTION DEC
 
signal idc_elpm    : std_logic; -- INSTRUCTION ELPM
signal idc_eor     : std_logic; -- INSTRUCTION EOR
 
signal idc_icall   : std_logic; -- INSTRUCTION ICALL
signal idc_ijmp    : std_logic; -- INSTRUCTION IJMP
 
signal idc_in      : std_logic; -- INSTRUCTION IN
signal idc_inc     : std_logic; -- INSTRUCTION INC
 
signal idc_jmp     : std_logic; -- INSTRUCTION JMP
 
signal idc_ld_x    : std_logic; -- INSTRUCTION LD Rx,X ; LD Rx,X+ ;LD Rx,-X
signal idc_ld_y    : std_logic; -- INSTRUCTION LD Rx,Y ; LD Rx,Y+ ;LD Rx,-Y
signal idc_ldd_y   : std_logic; -- INSTRUCTION LDD Rx,Y+q
signal idc_ld_z    : std_logic; -- INSTRUCTION LD Rx,Z ; LD Rx,Z+ ;LD Rx,-Z
signal idc_ldd_z   : std_logic; -- INSTRUCTION LDD Rx,Z+q
 
signal idc_ldi     : std_logic; -- INSTRUCTION LDI
signal idc_lds     : std_logic; -- INSTRUCTION LDS
signal idc_lpm     : std_logic; -- INSTRUCTION LPM
signal idc_lsr     : std_logic; -- INSTRUCTION LSR
 
signal idc_mov     : std_logic; -- INSTRUCTION MOV
signal idc_mul     : std_logic; -- INSTRUCTION MUL
 
signal idc_neg     : std_logic; -- INSTRUCTION NEG
signal idc_nop     : std_logic; -- INSTRUCTION NOP
 
signal idc_or      : std_logic; -- INSTRUCTION OR
signal idc_ori     : std_logic; -- INSTRUCTION ORI
signal idc_out     : std_logic; -- INSTRUCTION OUT
 
signal idc_pop     : std_logic; -- INSTRUCTION POP
signal idc_push    : std_logic; -- INSTRUCTION PUSH
 
signal idc_rcall   : std_logic; -- INSTRUCTION RCALL
signal idc_ret     : std_logic; -- INSTRUCTION RET
signal idc_reti    : std_logic; -- INSTRUCTION RETI
signal idc_rjmp    : std_logic; -- INSTRUCTION RJMP
signal idc_ror     : std_logic; -- INSTRUCTION ROR
 
signal idc_sbc     : std_logic; -- INSTRUCTION SBC
signal idc_sbci    : std_logic; -- INSTRUCTION SBCI
signal idc_sbi     : std_logic; -- INSTRUCTION SBI
signal idc_sbic    : std_logic; -- INSTRUCTION SBIC
signal idc_sbis    : std_logic; -- INSTRUCTION SBIS
signal idc_sbiw    : std_logic; -- INSTRUCTION SBIW
signal idc_sbrc    : std_logic; -- INSTRUCTION SBRC
signal idc_sbrs    : std_logic; -- INSTRUCTION SBRS
signal idc_sleep   : std_logic; -- INSTRUCTION SLEEP
 
signal idc_st_x    : std_logic; -- INSTRUCTION LD X,Rx ; LD X+,Rx ;LD -X,Rx
signal idc_st_y    : std_logic; -- INSTRUCTION LD Y,Rx ; LD Y+,Rx ;LD -Y,Rx
signal idc_std_y   : std_logic; -- INSTRUCTION LDD Y+q,Rx
signal idc_st_z    : std_logic; -- INSTRUCTION LD Z,Rx ; LD Z+,Rx ;LD -Z,Rx
signal idc_std_z   : std_logic; -- INSTRUCTION LDD Z+q,Rx
 
signal idc_sts     : std_logic; -- INSTRUCTION STS
signal idc_sub     : std_logic; -- INSTRUCTION SUB
signal idc_subi    : std_logic; -- INSTRUCTION SUBI
signal idc_swap    : std_logic; -- INSTRUCTION SWAP
 
signal idc_wdr     : std_logic; -- INSTRUCTION WDR
 
-- ADDITIONAL SIGNALS
signal idc_psinc   :  std_logic; -- POST INCREMENT FLAG FOR LD,ST INSTRUCTIONS
signal idc_prdec   :  std_logic; -- PRE DECREMENT  FLAG FOR LD,ST INSTRUCTIONS
 
-- ##################################################
 
-- SREG FLAGS WRITE ENABLE SIGNALS
 
--alias sreg_c_wr_en  : std_logic is sreg_fl_wr_en(0);
--alias sreg_z_wr_en  : std_logic is sreg_fl_wr_en(1);
--alias sreg_n_wr_en  : std_logic is sreg_fl_wr_en(2);
--alias sreg_v_wr_en  : std_logic is sreg_fl_wr_en(3);
--alias sreg_s_wr_en  : std_logic is sreg_fl_wr_en(4);
--alias sreg_h_wr_en  : std_logic is sreg_fl_wr_en(5);
--alias sreg_t_wr_en  : std_logic is sreg_fl_wr_en(6);
--alias sreg_i_wr_en  : std_logic is sreg_fl_wr_en(7);
 
signal sreg_c_wr_en  : std_logic; --  is sreg_fl_wr_en(0);
signal sreg_z_wr_en  : std_logic; --  is sreg_fl_wr_en(1);
signal sreg_n_wr_en  : std_logic; --  is sreg_fl_wr_en(2);
signal sreg_v_wr_en  : std_logic; --  is sreg_fl_wr_en(3);
signal sreg_s_wr_en  : std_logic; --  is sreg_fl_wr_en(4);
signal sreg_h_wr_en  : std_logic; --  is sreg_fl_wr_en(5);
signal sreg_t_wr_en  : std_logic; --  is sreg_fl_wr_en(6);
signal sreg_i_wr_en  : std_logic; --  is sreg_fl_wr_en(7);
 
signal sreg_bop_wr_en : std_logic_vector (7 downto 0);
 
signal sreg_adr_eq  : std_logic;
-- &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
 
begin
 
sreg_fl_wr_en <= sreg_i_wr_en & sreg_t_wr_en & sreg_h_wr_en & sreg_s_wr_en & sreg_v_wr_en & sreg_n_wr_en & sreg_z_wr_en & sreg_c_wr_en;
 
 
-- INSTRUCTION FETCH
instruction_reg_ena <= '1'; -- FOR TEST
 
instruction_fetch:process(cp2,ireset)
begin
if ireset='0' then                              -- RESET
instruction_reg <= (others => '0');
elsif (cp2='1' and cp2'event) then            -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable
  if instruction_reg_ena='1' then
   instruction_reg <= inst;
  end if;
 end if;
end if;
end process;
 
-- TWO WORDS INSTRUCTION DETECTOR (CONNECTED DIRECTLY TO THE INSTRUCTION REGISTER)
two_word_inst <= '1' when
((instruction_reg(15 downto 9)&instruction_reg(3 downto 1)="1001010111") or    -- CALL
 (instruction_reg(15 downto 9)&instruction_reg(3 downto 1)="1001010110")) or   -- JMP
 (instruction_reg(15 downto 9)&instruction_reg(3 downto 0) = "10010000000") or -- LDS
 (instruction_reg(15 downto 9)&instruction_reg(3 downto 0) = "10010010000")    -- STS
   else '0';  -- TO DETECT CALL/JMP/LDS/STS INSTRUCTIONS FOR SBRS/SBRC/SBIS/SBIC/CPSE
 
 
 
-- DATA EXTRACTOR (CONNECTED DIRECTLY TO THE INSTRUCTION REGISTER)
dex_dat8_immed <= instruction_reg(11 downto 8) & instruction_reg(3 downto 0);
dex_dat6_immed <= instruction_reg(7 downto 6) & instruction_reg(3 downto 0);
dex_adr12mem_s <= instruction_reg(11 downto 0);
dex_adr6port <= instruction_reg(10 downto 9) & instruction_reg(3 downto 0);
dex_adr5port <= instruction_reg(7 downto 3);
dex_adr_disp <= instruction_reg(13) & instruction_reg(11 downto 10) & instruction_reg(2 downto 0);
dex_condition <= instruction_reg(2 downto 0);
dex_bitop_bitnum <= instruction_reg(2 downto 0);      -- NUMBER(POSITION) OF TESTING BIT IN SBRC/SBRS/SBIC/SBIS INSTRUCTION
dex_bitnum_sreg <= instruction_reg(6 downto 4);
dex_adrreg_r  <=  instruction_reg(9) & instruction_reg(3 downto 0);
dex_adrreg_d  <= instruction_reg(8 downto 4);
dex_brxx_offset <= instruction_reg(9 downto 3);       -- OFFSET FOR BRBC/BRBS     
dex_adiw_sbiw_reg_adr <= instruction_reg(5 downto 4); -- ADDRESS OF THE LOW REGISTER FOR ADIW/SBIW INSTRUCTIONS
--dex_adrindreg <= instruction_reg(3 downto 2);     
 
-- LATCH Rd ADDDRESS FOR LDS/STS/POP INSTRUCTIONS
latcht_rd_adr:process(cp2,ireset)
begin
if ireset ='0' then
dex_adrreg_d_latched <= (others => '0');
elsif (cp2='1' and cp2'event) then
 if (cp2en='1') then                                                      -- Clock enable
  if ((idc_ld_x or idc_ld_y or idc_ldd_y or idc_ld_z or idc_ldd_z) or idc_sts or
          (idc_st_x  or idc_st_y or idc_std_y or idc_st_z or idc_std_z)or idc_lds or
           idc_pop)='1' then
   dex_adrreg_d_latched <= dex_adrreg_d;
  end if;
 end if;
end if;
end process;
-- +++++++++++++++++++++++++++++++++++++++++++++++++
 
 
-- R24:R25/R26:R27/R28:R29/R30:R31 ADIW/SBIW  ADDRESS CONTROL LOGIC
adiw_sbiw_encoder_out <= "11"&dex_adiw_sbiw_reg_adr&'0';
 
adiw_sbiw_high_reg_adr:process(cp2,ireset)
begin
if ireset ='0' then
adiw_sbiw_encoder_mux_out <= (others=>'0');
elsif(cp2='1' and cp2'event) then
 if (cp2en='1') then                                                      -- Clock enable
  adiw_sbiw_encoder_mux_out <= adiw_sbiw_encoder_out +1;
 end if;
end if;
end process;
 
-- ##########################
 
-- NOP INSERTION
 
--instruction_code_reg <= instruction_reg when nop_insert_st='0' else (others => '0');
instruction_code_reg <= (others => '0') when (nop_insert_st='1') else -- NOP
                        instruction_reg;                                                                                                -- Instruction 
 
 
nop_insert_st <= adiw_st or sbiw_st or cbi_st or sbi_st or rjmp_st or ijmp_st or pop_st or push_st or
              brxx_st or ld_st or st_st or ncall_st0 or nirq_st0 or nret_st0 or nreti_st0 or nlpm_st0 or njmp_st0 or
              nrcall_st0 or nicall_st0 or sts_st or lds_st or nskip_inst_st0;
 
 
-- INSTRUCTION DECODER (CONNECTED AFTER NOP INSERTION LOGIC)
 
idc_adc  <= '1' when instruction_code_reg(15 downto 10) = "000111" else '0'; -- 000111XXXXXXXXXX
idc_add  <= '1' when instruction_code_reg(15 downto 10) = "000011" else '0'; -- 000011XXXXXXXXXX
 
idc_adiw <= '1' when instruction_code_reg(15 downto 8) = "10010110" else '0'; -- 10010110XXXXXXXX
 
idc_and  <= '1' when instruction_code_reg(15 downto 10) = "001000" else '0'; -- 001000XXXXXXXXXX
idc_andi <= '1' when instruction_code_reg(15 downto 12) = "0111" else '0'; -- 0111XXXXXXXXXXXX
 
idc_asr  <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010100101" else '0'; -- 1001010XXXXX0101
 
idc_bclr <= '1' when instruction_code_reg(15 downto 7)&instruction_code_reg(3 downto 0) = "1001010011000" else '0'; -- 100101001XXX1000
 
idc_bld  <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3) = "11111000" else '0'; -- 1111100XXXXX0XXX
 
idc_brbc <= '1' when instruction_code_reg(15 downto 10) = "111101" else '0'; -- 111101XXXXXXXXXX
idc_brbs <= '1' when instruction_code_reg(15 downto 10) = "111100" else '0'; -- 111100XXXXXXXXXX
 
idc_bset <= '1' when instruction_code_reg(15 downto 7)&instruction_code_reg(3 downto 0) = "1001010001000" else '0'; -- 100101000XXX1000
 
idc_bst  <= '1' when instruction_code_reg(15 downto 9) = "1111101" else '0'; -- 1111101XXXXXXXXX
 
idc_call <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 1) = "1001010111" else '0'; -- 1001010XXXXX111X
 
idc_cbi  <= '1' when instruction_code_reg(15 downto 8) = "10011000" else '0'; -- 10011000XXXXXXXX
 
idc_com  <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010100000" else '0'; -- 1001010XXXXX0000
 
idc_cp   <= '1' when instruction_code_reg(15 downto 10) = "000101" else '0'; -- 000101XXXXXXXXXX
 
idc_cpc  <= '1' when instruction_code_reg(15 downto 10) = "000001" else '0'; -- 000001XXXXXXXXXX
 
idc_cpi  <= '1' when instruction_code_reg(15 downto 12) = "0011" else '0'; -- 0011XXXXXXXXXXXX
 
idc_cpse <= '1' when instruction_code_reg(15 downto 10) = "000100" else '0'; -- 000100XXXXXXXXXX
 
idc_dec  <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010101010" else '0'; -- 1001010XXXXX1010
 
idc_elpm <= '1' when instruction_code_reg = "1001010111011000" else '0'; -- 1001010111011000
 
idc_eor  <= '1' when instruction_code_reg(15 downto 10) = "001001" else '0'; -- 001001XXXXXXXXXX
 
idc_icall<= '1' when instruction_code_reg(15 downto 8)&instruction_code_reg(3 downto 0) = "100101011001" else '0'; -- 10010101XXXX1001
 
idc_ijmp <= '1' when instruction_code_reg(15 downto 8)&instruction_code_reg(3 downto 0) = "100101001001" else '0'; -- 10010100XXXX1001
 
idc_in   <= '1' when instruction_code_reg(15 downto 11) = "10110" else '0'; -- 10110XXXXXXXXXXX
 
idc_inc  <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010100011" else '0'; -- 1001010XXXXX0011
 
idc_jmp  <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 1) = "1001010110" else '0'; -- 1001010XXXXX110X
 
 
-- LD,LDD 
idc_ld_x <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010001100" or
                     instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010001101"  or
                                         instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010001110" else '0';
 
idc_ld_y <= '1' when (instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0)="10010001001" or
                                          instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0)="10010001010") else '0';
 
idc_ldd_y<= '1' when instruction_code_reg(15 downto 14)&instruction_code_reg(12)&instruction_code_reg(9)&instruction_code_reg(3) = "10001" else '0'; -- 10X0XX0XXXXX1XXX    
 
idc_ld_z <= '1' when (instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0)="10010000001" or
                                          instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0)="10010000010") else '0';
 
idc_ldd_z<= '1' when instruction_code_reg(15 downto 14)&instruction_code_reg(12)&instruction_code_reg(9)&instruction_code_reg(3) = "10000" else '0'; -- 10X0XX0XXXXX0XXX       
-- ######
 
 
idc_ldi <= '1' when instruction_code_reg(15 downto 12) = "1110" else '0'; -- 1110XXXXXXXXXXXX
 
idc_lds <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010000000" else '0'; -- 1001000XXXXX0000
 
idc_lpm <= '1' when instruction_code_reg = "1001010111001000" else '0'; -- 1001010111001000
 
idc_lsr <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010100110" else '0'; -- 1001010XXXXX0110
 
idc_mov <= '1' when instruction_code_reg(15 downto 10) = "001011" else '0'; -- 001011XXXXXXXXXX
 
idc_mul <= '1' when instruction_code_reg(15 downto 10) = "100111" else '0'; -- 100111XXXXXXXXXX
 
idc_neg <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010100001" else '0'; -- 1001010XXXXX0001
 
idc_nop <= '1' when instruction_code_reg = "0000000000000000" else '0'; -- 0000000000000000
 
idc_or  <= '1' when instruction_code_reg(15 downto 10) = "001010" else '0'; -- 001010XXXXXXXXXX
 
idc_ori <= '1' when instruction_code_reg(15 downto 12) = "0110" else '0'; -- 0110XXXXXXXXXXXX 
 
idc_out <= '1' when instruction_code_reg(15 downto 11) = "10111" else '0'; -- 10111XXXXXXXXXXX
 
idc_pop <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010001111" else '0'; -- 1001000XXXXX1111
 
idc_push<= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010011111" else '0'; -- 1001001XXXXX1111
 
idc_rcall<= '1' when instruction_code_reg(15 downto 12) = "1101" else '0'; -- 1101XXXXXXXXXXXX
 
idc_ret  <= '1' when instruction_code_reg(15 downto 7)&instruction_code_reg(4 downto 0) = "10010101001000" else '0'; -- 100101010XX01000
 
idc_reti <= '1' when instruction_code_reg(15 downto 7)&instruction_code_reg(4 downto 0) = "10010101011000" else '0'; -- 100101010XX11000
 
idc_rjmp <= '1' when instruction_code_reg(15 downto 12) = "1100" else '0'; -- 1100XXXXXXXXXXXX
 
idc_ror  <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010100111" else '0'; -- 1001010XXXXX0111
 
idc_sbc  <= '1' when instruction_code_reg(15 downto 10) = "000010" else '0'; -- 000010XXXXXXXXXX
 
idc_sbci <= '1' when instruction_code_reg(15 downto 12) = "0100" else '0'; -- 0100XXXXXXXXXXXX
 
idc_sbi  <= '1' when instruction_code_reg(15 downto 8) = "10011010" else '0'; -- 10011010XXXXXXXX
 
idc_sbic <= '1' when instruction_code_reg(15 downto 8) = "10011001" else '0'; -- 10011001XXXXXXXX
 
idc_sbis <= '1' when instruction_code_reg(15 downto 8) = "10011011" else '0'; -- 10011011XXXXXXXX
 
idc_sbiw <= '1' when instruction_code_reg(15 downto 8) = "10010111" else '0'; -- 10010111XXXXXXXX
 
idc_sbrc <= '1' when instruction_code_reg(15 downto 9) = "1111110" else '0'; -- 1111110XXXXXXXXX
 
idc_sbrs <= '1' when instruction_code_reg(15 downto 9) = "1111111" else '0'; -- 1111111XXXXXXXXX
 
idc_sleep<= '1' when instruction_code_reg(15 downto 5)&instruction_code_reg(3 downto 0) = "100101011001000" else '0'; -- 10010101100X1000
 
 
-- ST,STD
idc_st_x <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010011100" or
                     instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010011101" or
                     instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010011110" else '0';
 
idc_st_y <= '1' when (instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0)="10010011001" or
                                          instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0)="10010011010") else '0';
 
idc_std_y<= '1' when instruction_code_reg(15 downto 14)&instruction_code_reg(12)&instruction_code_reg(9)&instruction_code_reg(3) = "10011" else '0'; -- 10X0XX1XXXXX1XXX    
 
idc_st_z <= '1' when (instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0)="10010010001" or
                                          instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0)="10010010010") else '0';
 
idc_std_z<= '1' when instruction_code_reg(15 downto 14)&instruction_code_reg(12)&instruction_code_reg(9)&instruction_code_reg(3) = "10010" else '0'; -- 10X0XX1XXXXX0XXX 
-- ######
 
idc_sts  <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010010000" else '0'; -- 1001001XXXXX0000
 
idc_sub  <= '1' when instruction_code_reg(15 downto 10) = "000110" else '0'; -- 000110XXXXXXXXXX
 
idc_subi <= '1' when instruction_code_reg(15 downto 12) = "0101" else '0'; -- 0101XXXXXXXXXXXX
 
idc_swap <= '1' when instruction_code_reg(15 downto 9)&instruction_code_reg(3 downto 0) = "10010100010" else '0'; -- 1001010XXXXX0010
 
idc_wdr  <= '1' when instruction_code_reg(15 downto 5)&instruction_code_reg(3 downto 0) = "100101011011000" else '0'; -- 10010101101X1000
 
-- ADDITIONAL SIGNALS
idc_psinc <= '1' when (instruction_code_reg(1 downto 0) = "01" and
 (idc_st_x or idc_st_y or idc_st_z or idc_ld_x or idc_ld_y or idc_ld_z)='1') else '0';  -- POST INCREMENT FOR LD/ST INSTRUCTIONS
 
idc_prdec <= '1' when (instruction_code_reg(1 downto 0)  = "10" and
 (idc_st_x or idc_st_y or idc_st_z or idc_ld_x or idc_ld_y or idc_ld_z)='1') else '0';  -- PRE DECREMENT FOR LD/ST INSTRUCTIONS 
 
 
-- ##########################################################################################################
 
-- WRITE ENABLE SIGNALS FOR ramadr_reg
ramadr_reg_en <= idc_ld_x or idc_ld_y or idc_ldd_y or idc_ld_z or idc_ldd_z or idc_lds or    -- LD/LDD/LDS(two cycle execution) 
                 idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z or idc_sts or    -- ST/STS/STS(two cycle execution)
                                 idc_push or idc_pop or
                                 idc_rcall or (rcall_st1 and not cpuwait) or idc_icall or (icall_st1 and not cpuwait) or -- RCALL/ICALL
                                 call_st1 or  (call_st2 and not cpuwait) or irq_st1 or (irq_st2 and not cpuwait) or      -- CALL/IRQ
                                 idc_ret or (ret_st1 and not cpuwait ) or idc_reti or (reti_st1 and not cpuwait);                -- RET/RETI  -- ??
 
 
-- RAMADR MUX
ramadr_reg_in <= sph_out&spl_out when
  (idc_rcall or (rcall_st1 and not cpuwait)or idc_icall or (icall_st1 and not cpuwait)or  -- RCALL/ICALL
   call_st1  or (call_st2 and not cpuwait) or irq_st1   or (irq_st2 and not cpuwait)  or  -- CALL/IRQ
   idc_push )='1' else                                                                    -- PUSH
   (sph_out&spl_out)+1 when (idc_ret or (ret_st1 and not cpuwait)  or idc_reti  or (reti_st1 and not cpuwait) or idc_pop)='1' else  -- RET/RETI/POP
   inst when (idc_lds or idc_sts) ='1' else     -- LDS/STS (two cycle execution)        
   reg_h_out when (idc_ld_x or idc_ld_y or idc_ld_z or idc_st_x or idc_st_y or idc_st_z)='1' else  -- LD/ST       
   (reg_h_out + ("000000000"&dex_adr_disp));                                                       -- LDD/STD  
 
 
-- ADDRESS REGISTER                                                             
ramadr_reg:process(cp2,ireset)
begin
if ireset='0' then
ramadr_int <= (others => '0');
elsif(cp2='1' and cp2'event) then
 if (cp2en='1') then                                                      -- Clock enable
  if (ramadr_reg_en='1') then
   ramadr_int <= ramadr_reg_in;
  end if;
 end if;
end if;
end process;
 
ramadr <= ramadr_int;
 
-- GENERAL PURPOSE REGISTERS ADDRESSING FLAG FOR ST/STD/STS INSTRUCTIONS
gp_reg_adr:process(cp2,ireset)
begin
if ireset='0' then
reg_file_adr_space <='0';
elsif(cp2='1' and cp2'event) then
 if (cp2en='1') then                                                      -- Clock enable
  if (ramadr_reg_en='1') then
   if (ramadr_reg_in(15 downto 5)=const_ram_to_reg) then
    reg_file_adr_space <= '1';                             -- ADRESS RANGE 0x0000-0x001F -> REGISTERS (R0-R31)
   else
    reg_file_adr_space <= '0';
   end if;
  end if;
 end if;
end if;
end process;
 
-- I/O REGISTERS ADDRESSING FLAG FOR ST/STD/STS INSTRUCTIONS
io_reg_adr:process(cp2,ireset)
begin
if ireset='0' then io_file_adr_space<='0';
elsif(cp2='1' and cp2'event) then
 if (cp2en='1') then                                                      -- Clock enable
  if (ramadr_reg_en='1') then
   if (ramadr_reg_in(15 downto 5)=const_ram_to_io_a or ramadr_reg_in(15 downto 5)=const_ram_to_io_b) then
    io_file_adr_space <= '1';                             -- ADRESS RANGE 0x0020-0x005F -> I/O PORTS (0x00-0x3F)
   else
    io_file_adr_space <= '0';
   end if;
  end if;
 end if;
end if;
end process;
 
 
 
-- ##########################################################################################################
 
 
-- REGRE/REGWE LOGIC (5 BIT ADDSRESS BUS (INTERNAL ONLY) 32 LOCATIONS (R0-R31))
 
-- WRITE ENABLE FOR Rd REGISTERS 
alu_reg_wr <= idc_adc or idc_add or idc_adiw or adiw_st or idc_sub or idc_subi or idc_sbc or idc_sbci or
              idc_sbiw or  sbiw_st or idc_and or idc_andi or idc_or or idc_ori or idc_eor or idc_com or
                          idc_neg or idc_inc or idc_dec or idc_lsr or idc_ror or idc_asr or idc_swap;
 
 
reg_rd_wr <= idc_in or alu_reg_wr or idc_bld or             -- ALU INSTRUCTIONS + IN/BLD INSRTRUCTION                
 (pop_st or ld_st or lds_st)or                                      -- POP/LD/LDD/LDS INSTRUCTIONS
 ((st_st or sts_st) and reg_file_adr_space)or              -- ST/STD/STS INSTRUCTION          
  lpm_st2 or idc_ldi or idc_mov;                            -- LPM/LDI/MOV INSTRUCTION
 
 
  reg_rd_adr <= '1'&dex_adrreg_d(3 downto 0) when (idc_subi or idc_sbci or idc_andi or idc_ori or idc_cpi or idc_ldi)='1' else
                           "00000" when lpm_st2='1' else
               adiw_sbiw_encoder_out     when (idc_adiw or idc_sbiw)='1' else
               adiw_sbiw_encoder_mux_out when (adiw_st or sbiw_st)='1' else
                           dex_adrreg_d_latched      when (((st_st or sts_st) and not reg_file_adr_space) or ld_st or lds_st or pop_st)='1' else
               ramadr_int(4 downto 0)    when ((st_st or sts_st) and reg_file_adr_space)='1'else --!!??
                           dex_adrreg_d;
 
  reg_rd_adr_int <= '1'&dex_adrreg_d(3 downto 0) when (idc_subi or idc_sbci or idc_andi or idc_ori or idc_cpi or idc_ldi)='1' else
                           "00000" when lpm_st2='1' else
               adiw_sbiw_encoder_out     when (idc_adiw or idc_sbiw)='1' else
               adiw_sbiw_encoder_mux_out when (adiw_st or sbiw_st)='1' else
                           dex_adrreg_d_latched      when (((st_st or sts_st) and not reg_file_adr_space) or ld_st or lds_st or pop_st)='1' else
               ramadr_int(4 downto 0)    when ((st_st or sts_st) and reg_file_adr_space)='1'else --!!??
                           dex_adrreg_d;
 
reg_rr_adr <= ramadr_int(4 downto 0) when ((ld_st or lds_st) and reg_file_adr_space)='1'else --!!??
                  dex_adrreg_d_latched   when ((st_st or sts_st) and reg_file_adr_space)='1'else --!!??
                  dex_adrreg_r;
 
-- MULTIPLEXER FOR REGISTER FILE Rd INPUT
reg_rd_in <= dbusin when (idc_in or ((lds_st or ld_st)and not reg_file_adr_space) or pop_st)='1' else -- FROM INPUT DATA BUS
                         reg_rr_out when ((lds_st or ld_st)  and reg_file_adr_space)='1' else
             gp_reg_tmp when ((st_st or sts_st)  and reg_file_adr_space)='1' else -- ST/STD/STS &  ADDRESS FROM 0 TO 31 (REGISTER FILE)
                         bld_op_out when (idc_bld='1')else                                     -- FROM BIT PROCESSOR BLD COMMAND
             reg_rr_out when (idc_mov='1')else                                     -- FOR MOV INSTRUCTION 
                         instruction_reg(15 downto 8) when (lpm_st2='1' and reg_z_out(0)='1') else -- LPM/ELPM
                         instruction_reg(7 downto 0) when  (lpm_st2='1' and reg_z_out(0)='0') else -- LPM/ELPM
             dex_dat8_immed when idc_ldi='1' else
                         alu_data_out;                                               -- FROM ALU DATA OUT
 
-- IORE/IOWE LOGIC (6 BIT ADDRESS adr[5..0] FOR I/O PORTS(64 LOCATIONS))
iore_int <= idc_in or idc_sbi or idc_cbi or idc_sbic or idc_sbis or ((ld_st or lds_st) and io_file_adr_space);   -- IN/SBI/CBI 
iowe_int <= '1' when ((idc_out or sbi_st or cbi_st) or
                     ((st_st or sts_st) and io_file_adr_space))='1' else '0'; -- OUT/SBI/CBI + !! ST/STS/STD
 
 
-- adr[5..0] BUS MULTIPLEXER
adr_int <= dex_adr6port when (idc_in or idc_out) = '1' else                          -- IN/OUT INSTRUCTIONS  
           '0'&dex_adr5port when (idc_cbi or idc_sbi or idc_sbic or idc_sbis) ='1'    else  -- CBI/SBI (READ PHASE) + SBIS/SBIC
                   '0'&cbi_sbi_io_adr_tmp when (cbi_st or sbi_st)='1' else       -- CBI/SBI (WRITE PHASE)
                    ramadr_int(6)&ramadr_int(4 downto 0);                                                   -- LD/LDS/LDD/ST/STS/STD
 
-- ramre LOGIC (16 BIT ADDRESS ramadr[15..0] FOR DATA RAM (64*1024-64-32 LOCATIONS))
--ramre_int <= not(reg_file_adr_space or io_file_adr_space) and 
--            (ld_st or lds_st2 or pop_st or                    -- LD/LDD/LDS/POP/
--             ret_st1 or ret_st2 or reti_st1 or reti_st2);     -- RET/RETI
 
DataMemoryRead:process(cp2,ireset)
begin
if ireset='0' then -- Reset
 ramre_int <= '0';
elsif (cp2='1' and cp2'event) then -- Clock
 if (cp2en='1') then                                                      -- Clock enable       
  case ramre_int is
   when '0' =>
    if(ramadr_reg_in(15 downto 5)/=const_ram_to_io_a and
           ramadr_reg_in(15 downto 5)/=const_ram_to_io_b and
       ramadr_reg_in(15 downto 5)/=const_ram_to_reg  and
      (idc_ld_x or idc_ld_y or idc_ldd_y or idc_ld_z or idc_ldd_z or  -- LD/LDD instruction     
           idc_lds or                                                     -- LDS instruction(two cycle execution)
           idc_pop or                                                     -- POP instruction
       idc_ret or                                                       -- RET instruction 
           idc_reti)='1')                                                                                                   -- RETI instruction 
           then ramre_int <='1';
    end if;
   when '1' =>
    if ((ld_st or lds_st or pop_st or ret_st2 or reti_st2)and not cpuwait)='1' then
     ramre_int <='0';
    end if;
   when others  =>      null;
  end case;
 end if;
end if;
end process;
 
-- ramwe LOGIC (16 BIT ADDRESS ramadr[15..0] FOR DATA RAM (64*1024-64-32 LOCATIONS))
--ramwe_int <= not(reg_file_adr_space or io_file_adr_space) and 
--            (st_st or sts_st2 or push_st or rcall_st1 or rcall_st2 or -- ST/STD/STS/PUSH/RCALL
--                                                      icall_st1 or icall_st2 or -- ICALL
--                                                      call_st2 or call_st3 or   -- CALL
--                                                                                      irq_st2 or irq_st3);      -- INTERRUPT
 
DataMemoryWrite:process(cp2,ireset)
begin
if ireset='0' then -- Reset
 ramwe_int <= '0';
elsif (cp2='1' and cp2'event) then -- Clock
 if (cp2en='1') then                                                      -- Clock enable
  case ramwe_int is
   when '0' =>
    if(ramadr_reg_in(15 downto 5)/=const_ram_to_io_a and
           ramadr_reg_in(15 downto 5)/=const_ram_to_io_b and
       ramadr_reg_in(15 downto 5)/=const_ram_to_reg  and
      (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z or  -- ST/STD instruction     
           idc_sts or                                                     -- STS instruction (two cycle execution)      
           idc_push or                                                    -- PUSH instruction
           idc_rcall or                                                                                                   -- RCALL instruction
           idc_icall or                                                                                                   -- ICALL instruction
           call_st1 or                                                    -- CALL instruction
           irq_st1)='1')                                                  -- Interrupt  
          then ramwe_int <='1';
    end if;
   when '1' =>
    if ((st_st or sts_st or push_st or rcall_st2 or
             icall_st2 or call_st3 or irq_st3)and not cpuwait)='1' then ramwe_int <='0';
    end if;
   when others  =>      null;
  end case;
end if;
end if;
end process;
 
-- DBUSOUT MULTIPLEXER
--dbusout_mux_logic: for i in dbusout_int'range generate
--dbusout_int(i)<= (reg_rd_out(i) and (idc_push or idc_sts or
--                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
--                               (gp_reg_tmp(i) and (st_st or sts_st))or                            -- NEW
--                               (bitpr_io_out(i) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
--                 (program_counter(i)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC                 (program_counter_high_fr(i) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
--                 (pc_for_interrupt(i) and irq_st1) or
--                               (pc_for_interrupt(8) and irq_st2) or
--                               (reg_rd_out(i) and  idc_out); -- OUT
--end generate;
 
dbusout_int(0)<= (reg_rd_out(0) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(0) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(0) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(0)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(0) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(0) and irq_st1) or
                                 (pc_for_interrupt(8) and irq_st2) or
                                 (reg_rd_out(0) and  idc_out); -- OUT
 
dbusout_int(1)<= (reg_rd_out(1) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(1) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(1) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(1)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(1) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(1) and irq_st1) or
                                 (pc_for_interrupt(9) and irq_st2) or
                                 (reg_rd_out(1) and  idc_out); -- OUT
 
dbusout_int(2)<= (reg_rd_out(2) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(2) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(2) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(2)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(2) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(2) and irq_st1) or
                                 (pc_for_interrupt(10) and irq_st2) or
                                 (reg_rd_out(2) and  idc_out); -- OUT
 
dbusout_int(3)<= (reg_rd_out(3) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(3) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(3) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(3)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(3) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(3) and irq_st1) or
                                 (pc_for_interrupt(11) and irq_st2) or
                                 (reg_rd_out(3) and  idc_out); -- OUT
 
dbusout_int(4)<= (reg_rd_out(4) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(4) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(4) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(4)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(4) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(4) and irq_st1) or
                                 (pc_for_interrupt(12) and irq_st2) or
                                 (reg_rd_out(4) and  idc_out); -- OUT
 
dbusout_int(5)<= (reg_rd_out(5) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(5) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(5) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(5)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(5) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(5) and irq_st1) or
                                 (pc_for_interrupt(13) and irq_st2) or
                                 (reg_rd_out(5) and  idc_out); -- OUT
 
dbusout_int(6)<= (reg_rd_out(6) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(6) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(6) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(6)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(6) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(6) and irq_st1) or
                                 (pc_for_interrupt(14) and irq_st2) or
                                 (reg_rd_out(6) and  idc_out); -- OUT
 
dbusout_int(7)<= (reg_rd_out(7) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(7) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(7) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(7)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(7) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(7) and irq_st1) or
                                 (pc_for_interrupt(15) and irq_st2) or
                                 (reg_rd_out(7) and  idc_out); -- OUT
 
dbusout_int_route <= dbusout_int;
 
dbusout(0)<= (reg_rd_out_int(0) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(0) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(0) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(0)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(0) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(0) and irq_st1) or
                                 (pc_for_interrupt(8) and irq_st2) or
                                 (reg_rd_out_int(0) and  idc_out); -- OUT
 
dbusout(1)<= (reg_rd_out_int(1) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(1) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(1) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(1)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(1) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(1) and irq_st1) or
                                 (pc_for_interrupt(9) and irq_st2) or
                                 (reg_rd_out_int(1) and  idc_out); -- OUT
 
dbusout(2)<= (reg_rd_out_int(2) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(2) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(2) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(2)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(2) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(2) and irq_st1) or
                                 (pc_for_interrupt(10) and irq_st2) or
                                 (reg_rd_out_int(2) and  idc_out); -- OUT
 
dbusout(3)<= (reg_rd_out_int(3) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(3) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(3) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(3)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(3) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(3) and irq_st1) or
                                 (pc_for_interrupt(11) and irq_st2) or
                                 (reg_rd_out_int(3) and  idc_out); -- OUT
 
dbusout(4)<= (reg_rd_out_int(4) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(4) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(4) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(4)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(4) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(4) and irq_st1) or
                                 (pc_for_interrupt(12) and irq_st2) or
                                 (reg_rd_out_int(4) and  idc_out); -- OUT
 
dbusout(5)<= (reg_rd_out_int(5) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(5) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(5) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(5)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(5) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(5) and irq_st1) or
                                 (pc_for_interrupt(13) and irq_st2) or
                                 (reg_rd_out_int(5) and  idc_out); -- OUT
 
dbusout(6)<= (reg_rd_out_int(6) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(6) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(6) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(6)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(6) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(6) and irq_st1) or
                                 (pc_for_interrupt(14) and irq_st2) or
                                 (reg_rd_out_int(6) and  idc_out); -- OUT
 
dbusout(7)<= (reg_rd_out_int(7) and (idc_push or idc_sts or
                 (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)))or      -- PUSH/ST/STD/STS INSTRUCTIONS
                                 (gp_reg_tmp(7) and (st_st or sts_st))or                            -- NEW
                                 (bitpr_io_out(7) and (cbi_st or sbi_st))or                          -- CBI/SBI  INSTRUCTIONS
                 (program_counter(7)         and (idc_rcall or idc_icall or call_st1))or                        -- LOW  PART OF PC
                 (program_counter_high_fr(7) and (rcall_st1 or icall_st1 or call_st2))or                        -- HIGH PART OF PC
                 (pc_for_interrupt(7) and irq_st1) or
                                 (pc_for_interrupt(15) and irq_st2) or
                                 (reg_rd_out_int(7) and  idc_out); -- OUT
 
 
-- ALU CONNECTION
 
-- ALU Rr INPUT MUX
alu_data_r_in <= dex_dat8_immed       when (idc_subi or idc_sbci or idc_andi or idc_ori or idc_cpi)='1' else
                 "00"&dex_dat6_immed  when (idc_adiw or idc_sbiw) ='1' else
                 "00000000"           when (adiw_st or sbiw_st) ='1' else
                 reg_rr_out;
 
 
-- gp_reg_tmp STORES TEMPREOARY THE VALUE OF SOURCE REGISTER DURING ST/STD/STS INSTRUCTION
gp_registers_trig:process(cp2,ireset)
begin
if (ireset='0') then
gp_reg_tmp <= (others=>'0');
elsif (cp2='1' and cp2'event) then
 if (cp2en='1') then                                                      -- Clock enable
  -- if ((idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z) or sts_st1)='1' then  -- CLOCK ENABLE
  if ((idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z) or idc_sts)='1' then  -- CLOCK ENABLE
     gp_reg_tmp <= reg_rd_out;
  end if;
 end if;
end if;
end process;
 
-- **********************************************************************************************************
 
-- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-- +++++++++++++++++++++++++++++++++++++++ PROGRAM COUNTER ++++++++++++++++++++++++++++++++++++++++++++++++++
-- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
program_counter_high_store:process(cp2,ireset)
begin
if ireset='0' then                         -- RESET
program_counter_high_fr <=(others => '0');
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable
  if (idc_rcall or idc_icall or call_st1 or irq_st1) ='1' then
   program_counter_high_fr <= program_counter(15 downto 8);       -- STORE HIGH BYTE OF THE PROGRAMM COUNTER FOR RCALL/ICALL/CALL INSTRUCTIONS AND INTERRUPTS   
  end if;
 end if;
end if;
end process;
 
 
program_counter_for_lpm_elpm:process(cp2,ireset)
begin
if ireset='0' then                         -- RESET
program_counter_tmp<=(others => '0');
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable
  if (idc_lpm or idc_elpm) ='1' then
   program_counter_tmp <= program_counter;
  end if;
 end if;
end if;
end process;
 
pa15_pm <= rampz_out(0) and idc_elpm; -- '0' WHEN LPM INSTRUCTIONS  RAMPZ(0) WHEN ELPM INSTRUCTION
 
-- OFFSET FOR BRBC/BRBS INSTRUCTIONS +63/-64
offset_brbx <= "0000000000"&dex_brxx_offset(5 downto 0) when (dex_brxx_offset(6)='0') else -- +
               "1111111111"&dex_brxx_offset(5 downto 0);                                   -- - 
 
-- OFFSET FOR RJMP/RCALL INSTRUCTIONS +2047/-2048
offset_rxx <= "00000"&dex_adr12mem_s(10 downto 0) when (dex_adr12mem_s(11)='0') else       -- +
              "11111"&dex_adr12mem_s(10 downto 0);                                          -- -
 
program_counter <= pc_high&pc_low;
 
program_counter_in <= program_counter + offset_brbx when ((idc_brbc or idc_brbs) and  bit_test_op_out) ='1'else  -- BRBC/BRBS                  
                      program_counter + offset_rxx when (idc_rjmp or idc_rcall)='1'else     -- RJMP/RCALL
                      reg_z_out when (idc_ijmp or idc_icall)='1'else                        -- IJMP/ICALL
                      pa15_pm&reg_z_out(15 downto 1) when (idc_lpm or idc_elpm) ='1'else    -- LPM/ELPM
                      instruction_reg  when (jmp_st1 or call_st1)='1'else                    -- JMP/CALL
                      "0000000000"&irqackad_int&'0' when irq_st1 ='1' else                 -- INTERRUPT      
                      dbusin&"00000000"  when (ret_st1 or reti_st1)='1' else                 -- RET/RETI -> PC HIGH BYTE                  
                      "00000000"&dbusin  when (ret_st2 or reti_st2)='1' else                 -- RET/RETI -> PC LOW BYTE                       
                      program_counter_tmp when (lpm_st1)='1'                                 -- AFTER LPM/ELPM INSTRUCTION   
                      else program_counter+1;      -- THE MOST USUAL CASE
 
 
 
pc_low_en  <= not (idc_ld_x or idc_ld_y or idc_ld_z or idc_ldd_y or idc_ldd_z or
                       idc_st_x or idc_st_y or idc_st_z or idc_std_y or idc_std_z or
                                   ((sts_st or lds_st) and cpuwait)or
                                   idc_adiw or idc_sbiw or
                                   idc_push or idc_pop or
                                   idc_cbi or idc_sbi or
                                   rcall_st1 or icall_st1 or call_st2 or irq_st2 or cpuwait or
                                   ret_st1 or reti_st1);
 
 
pc_high_en <= not (idc_ld_x or idc_ld_y or idc_ld_z or idc_ldd_y or idc_ldd_z or
                       idc_st_x or idc_st_y or idc_st_z or idc_std_y or idc_std_z or
                                   ((sts_st or lds_st) and cpuwait) or
                                   idc_adiw or idc_sbiw or
                                   idc_push or idc_pop or
                                   idc_cbi or idc_sbi or
                                   rcall_st1 or icall_st1 or call_st2 or irq_st2 or cpuwait or
                                   ret_st2 or reti_st2);
 
program_counter_low:process(cp2,ireset)
begin
if ireset='0' then                              -- RESET
pc_low<=(others => '0');
elsif (cp2='1' and cp2'event) then              -- CLOCK
 if (cp2en='1') then                                                    -- Clock enable
  if pc_low_en ='1' then
   pc_low <= program_counter_in(7 downto 0);
  end if;
 end if;
end if;
end process;
 
program_counter_high:process(cp2,ireset)
begin
if ireset='0' then                               -- RESET
pc_high<=(others => '0');
elsif (cp2='1' and cp2'event) then               -- CLOCK
 if (cp2en='1') then                                                     -- Clock enable
  if pc_high_en ='1' then
   pc_high <= program_counter_in(15 downto 8);
  end if;
 end if;
end if;
end process;
 
pc <= program_counter;
 
 
program_counter_for_interrupt:process(cp2,ireset)
begin
if ireset='0' then                                 -- RESET
pc_for_interrupt <=(others => '0');
elsif (cp2='1' and cp2'event) then               -- CLOCK
 if (cp2en='1') then                                                     -- Clock enable
  if irq_start ='1' then
   pc_for_interrupt <= program_counter;
  end if;
 end if;
end if;
end process;
 
-- END OF PROGRAM COUNTER 
 
-- STATE MACHINES
 
skip_inst_start <= ((idc_sbrc or idc_sbrs or idc_sbic or idc_sbis) and bit_test_op_out)or
                   (idc_cpse and alu_z_flag_out);
 
skip_instruction_sm:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
nskip_inst_st0 <= '0';
skip_inst_st1  <= '0';
skip_inst_st2  <= '0';
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                 -- Clock enable
  nskip_inst_st0 <= (not nskip_inst_st0 and skip_inst_start) or
                    (nskip_inst_st0 and not((skip_inst_st1 and not two_word_inst) or skip_inst_st2));
  skip_inst_st1  <= (not skip_inst_st1 and not nskip_inst_st0 and skip_inst_start);
  skip_inst_st2  <=  not skip_inst_st2 and skip_inst_st1 and two_word_inst;
 end if;
end if;
end process;
 
 
 
alu_state_machines:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
adiw_st <= '0';
sbiw_st <= '0';
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                     -- Clock enable
  adiw_st <= not adiw_st and idc_adiw;
  sbiw_st <= not sbiw_st and idc_sbiw;
 end if;
end if;
end process;
 
 
lpm_state_machine:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
nlpm_st0 <= '0';
lpm_st1 <= '0';
lpm_st2 <= '0';
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable
  nlpm_st0 <= (not nlpm_st0 and (idc_lpm or idc_elpm)) or (nlpm_st0 and not lpm_st2);
  lpm_st1  <= (not lpm_st1 and not nlpm_st0 and (idc_lpm or idc_elpm)); -- ?? 
  lpm_st2  <=  not lpm_st2 and lpm_st1;
 end if;
end if;
end process;
 
 
lds_state_machine:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
 lds_st <= '0';
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable       
  lds_st  <= (not lds_st and idc_lds) or (lds_st and cpuwait);
 end if;
end if;
end process;
 
 
sts_state_machine:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
 sts_st <= '0';
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable
  sts_st  <= (not sts_st and idc_sts) or (sts_st and cpuwait);
 end if;
end if;
end process;
 
jmp_state_machine:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
njmp_st0 <= '0';
jmp_st1 <= '0';
jmp_st2 <= '0';
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable
  njmp_st0 <= (not njmp_st0 and idc_jmp) or (njmp_st0 and not jmp_st2);
  jmp_st1  <= not jmp_st1 and not njmp_st0 and idc_jmp; -- ?? 
  jmp_st2  <= not jmp_st2 and jmp_st1;
 end if;
end if;
end process;
 
rcall_state_machine:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
nrcall_st0 <= '0';
rcall_st1 <= '0';
rcall_st2 <= '0';
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable       
  nrcall_st0 <= (not nrcall_st0 and idc_rcall) or (nrcall_st0 and not (rcall_st2 and not cpuwait));
  rcall_st1  <= (not rcall_st1 and not nrcall_st0 and idc_rcall) or (rcall_st1 and cpuwait);
  rcall_st2  <= (not rcall_st2 and rcall_st1 and not cpuwait) or (rcall_st2 and cpuwait);
 end if;
end if;
end process;
 
icall_state_machine:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
nicall_st0 <= '0';
icall_st1 <= '0';
icall_st2 <= '0';
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable       
  nicall_st0 <= (not nicall_st0 and idc_icall) or (nicall_st0 and not (icall_st2 and not cpuwait));
  icall_st1  <= (not icall_st1 and not nicall_st0 and idc_icall) or (icall_st1 and cpuwait);
  icall_st2  <= (not icall_st2 and icall_st1 and not cpuwait) or (icall_st2 and cpuwait);
 end if;
end if;
end process;
 
call_state_machine:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
ncall_st0 <= '0';
call_st1 <= '0';
call_st2 <= '0';
call_st3  <= '0';
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable
  ncall_st0 <= (not ncall_st0 and idc_call) or (ncall_st0 and not( call_st3 and not cpuwait));
  call_st1  <= not call_st1 and not ncall_st0 and idc_call;
  call_st2  <= (not call_st2 and call_st1) or (call_st2 and cpuwait);
  call_st3  <= (not call_st3 and call_st2 and not cpuwait) or (call_st3 and cpuwait);
 end if;
end if;
end process;
 
ret_state_machine:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
nret_st0 <= '0';
ret_st1 <= '0';
ret_st2 <= '0';
ret_st3  <= '0';
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable
  nret_st0 <= (not nret_st0 and idc_ret) or (nret_st0 and not ret_st3);
  ret_st1  <= (not ret_st1 and not nret_st0 and idc_ret) or (ret_st1 and cpuwait);
  ret_st2  <= (not ret_st2 and ret_st1 and not cpuwait) or (ret_st2 and cpuwait) ;
  ret_st3  <= not ret_st3 and ret_st2 and not cpuwait;
 end if;
end if;
end process;
 
reti_state_machine:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
nreti_st0 <= '0';
reti_st1 <= '0';
reti_st2 <= '0';
reti_st3  <= '0';
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable
  nreti_st0 <= (not nreti_st0 and idc_reti) or (nreti_st0 and not reti_st3);
  reti_st1  <= (not reti_st1 and not nreti_st0 and idc_reti) or (reti_st1 and cpuwait);
  reti_st2  <= (not reti_st2 and reti_st1 and not cpuwait) or (reti_st2 and cpuwait) ;
  reti_st3  <= not reti_st3 and reti_st2 and not cpuwait;
 end if;
end if;
end process;
 
 
-- INTERRUPT LOGIC AND STATE MACHINE 
 
irq_int <= '0' when      irqlines="00000000000000000000000" else '1';
 
irq_vector_adr(15 downto 6)<=(others => '0');
irq_vector_adr(0) <= '0';
-- PRIORITY ENCODER
irq_vector_adr(5 downto 1) <= "00001" when irqlines(0)='1'  else -- 0x0002
                              "00010" when irqlines(1)='1'  else -- 0x0004  
                              "00011" when irqlines(2)='1'  else -- 0x0006  
                              "00100" when irqlines(3)='1'  else -- 0x0008  
                              "00101" when irqlines(4)='1'  else -- 0x000A  
                              "00110" when irqlines(5)='1'  else -- 0x000C  
                              "00111" when irqlines(6)='1'  else -- 0x000E  
                              "01000" when irqlines(7)='1'  else -- 0x0010  
                              "01001" when irqlines(8)='1'  else -- 0x0012  
                              "01010" when irqlines(9)='1'  else -- 0x0014
                              "01011" when irqlines(10)='1' else -- 0x0016
                              "01100" when irqlines(11)='1' else -- 0x0018
                              "01101" when irqlines(12)='1' else -- 0x001A
                              "01110" when irqlines(13)='1' else -- 0x001C
                              "01111" when irqlines(14)='1' else -- 0x001E
                              "10000" when irqlines(15)='1' else -- 0x0020
                              "10001" when irqlines(16)='1' else -- 0x0022
                              "10010" when irqlines(17)='1' else -- 0x0024
                              "10011" when irqlines(18)='1' else -- 0x0026
                              "10100" when irqlines(19)='1' else -- 0x0028
                              "10101" when irqlines(20)='1' else -- 0x002A
                              "10110" when irqlines(21)='1' else -- 0x002C
                              "10111" when irqlines(22)='1' else -- 0x002E                                                                
                                                          "00000";
 
-- MULTI CYCLE INSTRUCTION FLAG FOR IRQ
cpu_busy <= idc_adiw or idc_sbiw or idc_cbi or idc_sbi or
            idc_rjmp or idc_ijmp or
                        idc_jmp or jmp_st1 or
--                      idc_brbs or idc_brbc or -- Old variant
            ((idc_brbc or idc_brbs) and  bit_test_op_out) or
                        idc_lpm or lpm_st1 or
                        skip_inst_start or (skip_inst_st1 and two_word_inst) or
                        idc_ld_x or idc_ld_y or idc_ldd_y or idc_ld_z or idc_ldd_z or (ld_st and cpuwait) or
                        idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z or (st_st and cpuwait) or
                        idc_lds or (lds_st and cpuwait) or
                        idc_sts or (sts_st and cpuwait) or
                        idc_rcall or rcall_st1 or (rcall_st2 and cpuwait) or           -- RCALL
                        idc_icall or icall_st1 or (icall_st2 and cpuwait) or               -- ICALL
                        idc_call or call_st1 or call_st2 or (call_st3 and cpuwait) or  -- CALL
                        idc_push or (push_st and cpuwait) or                           -- PUSH (added 14.07.05)
                        idc_pop or (pop_st and cpuwait) or                             -- POP  (added 14.07.05)
                    (idc_bclr and sreg_bop_wr_en(7)) or                 -- ??? CLI
                    (iowe_int and sreg_adr_eq and not dbusout_int(7))or -- ??? Writing '0' to I flag (OUT/STD/ST/STD)
                        nirq_st0 or
--                      idc_ret  or nret_st0 or                             -- Old variant 
                        idc_ret or ret_st1 or ret_st2 or
--                      idc_reti or nreti_st0;                              -- At least one instruction must be executed after RETI and before the new interrupt.
                        idc_reti or reti_st1 or reti_st2;
 
sreg_adr_eq <= '1' when adr_int=SREG_Address else '0';
 
--irq_start <= irq_int and not cpu_busy and globint;
irq_start <= irq_int and not cpu_busy and globint;
 
irq_state_machine:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
nirq_st0 <= '0';
irq_st1 <= '0';
irq_st2 <= '0';
irq_st3 <= '0';
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable       
  nirq_st0 <= (not nirq_st0 and irq_start) or (nirq_st0 and not (irq_st3 and not cpuwait));
  irq_st1  <= (not irq_st1 and not nirq_st0 and irq_start);
  irq_st2  <= (not irq_st2 and irq_st1) or (irq_st2 and cpuwait);
  irq_st3  <= (not irq_st3 and irq_st2 and not cpuwait) or (irq_st3 and cpuwait);
 end if;
end if;
end process;
 
irqack_reg:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
irqack_int<='0';
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable       
  irqack_int<= not irqack_int and irq_start;
 end if;
end if;
end process;
irqack <= irqack_int;
 
irqackad_reg:process(cp2,ireset)
begin
if ireset='0' then                                -- RESET
irqackad_int<=(others=>'0');
elsif (cp2='1' and cp2'event) then              -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable
  irqackad_int <= irq_vector_adr(5 downto 1);
 end if;
end if;
end process;
irqackad <= irqackad_int;
 
-- *******************************************************************************************
 
rjmp_push_pop_ijmp_state_brxx_machine:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
rjmp_st <= '0';
ijmp_st <= '0';
push_st <= '0';
pop_st <= '0';
brxx_st <= '0';
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable
  rjmp_st <= idc_rjmp;    -- ??
  ijmp_st <= idc_ijmp;
  push_st <= (not push_st and idc_push) or (push_st and cpuwait);
  pop_st  <= (not pop_st  and idc_pop) or (pop_st and cpuwait);
  brxx_st <= not brxx_st and (idc_brbc or idc_brbs) and bit_test_op_out;
 end if;
end if;
end process;
 
-- LD/LDD/ST/STD
ld_st_state_machine:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
ld_st <= '0';
st_st <= '0';
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable       
  ld_st <= (not ld_st and (idc_ld_x or idc_ld_y or idc_ldd_y or idc_ld_z or idc_ldd_z)) or (ld_st and cpuwait);
  st_st <= (not st_st and (idc_st_x or idc_st_y or idc_std_y or idc_st_z or idc_std_z)) or (st_st and cpuwait);
 end if;
end if;
end process;
 
-- SBI/CBI
sbi_cbi_machine:process(cp2,ireset)
begin
if ireset='0' then                       -- RESET
sbi_st <= '0';
cbi_st <= '0';
cbi_sbi_io_adr_tmp  <= (others => '0');
cbi_sbi_bit_num_tmp     <= (others => '0');
elsif (cp2='1' and cp2'event) then       -- CLOCK
 if (cp2en='1') then                                                      -- Clock enable
  sbi_st <= not sbi_st and idc_sbi;
  cbi_st <= not cbi_st and idc_cbi;
  cbi_sbi_io_adr_tmp <= dex_adr5port;
  cbi_sbi_bit_num_tmp <= dex_bitop_bitnum;
 end if;
end if;
end process;
 
-- ########################################################################################
 
-- SREG FLAGS WRITE ENABLE LOGIC
 
--bclr_bset_op_en_logic:for i in sreg_bop_wr_en'range generate
--sreg_bop_wr_en(i) <= '1' when (dex_bitnum_sreg=i and (idc_bclr or idc_bset)='1') else '0';
--end generate;
 
sreg_bop_wr_en(0) <= '1' when (dex_bitnum_sreg=0 and (idc_bclr or idc_bset)='1') else '0';
sreg_bop_wr_en(1) <= '1' when (dex_bitnum_sreg=1 and (idc_bclr or idc_bset)='1') else '0';
sreg_bop_wr_en(2) <= '1' when (dex_bitnum_sreg=2 and (idc_bclr or idc_bset)='1') else '0';
sreg_bop_wr_en(3) <= '1' when (dex_bitnum_sreg=3 and (idc_bclr or idc_bset)='1') else '0';
sreg_bop_wr_en(4) <= '1' when (dex_bitnum_sreg=4 and (idc_bclr or idc_bset)='1') else '0';
sreg_bop_wr_en(5) <= '1' when (dex_bitnum_sreg=5 and (idc_bclr or idc_bset)='1') else '0';
sreg_bop_wr_en(6) <= '1' when (dex_bitnum_sreg=6 and (idc_bclr or idc_bset)='1') else '0';
sreg_bop_wr_en(7) <= '1' when (dex_bitnum_sreg=7 and (idc_bclr or idc_bset)='1') else '0';
 
sreg_c_wr_en <= idc_add or idc_adc or (idc_adiw or adiw_st) or idc_sub  or idc_subi or
                idc_sbc or idc_sbci or (idc_sbiw or sbiw_st) or idc_com or idc_neg or
                                idc_cp or idc_cpc or idc_cpi or
                idc_lsr or idc_ror or idc_asr or sreg_bop_wr_en(0);
 
sreg_z_wr_en <= idc_add or idc_adc or (idc_adiw or adiw_st) or idc_sub  or idc_subi or
                idc_sbc or idc_sbci or (idc_sbiw or sbiw_st) or
                                idc_cp or idc_cpc or idc_cpi or
                idc_and or idc_andi or idc_or or idc_ori or idc_eor or idc_com or idc_neg or
                idc_inc or idc_dec or idc_lsr or idc_ror or idc_asr or sreg_bop_wr_en(1);
 
 
sreg_n_wr_en <= idc_add or idc_adc or adiw_st or idc_sub  or idc_subi or
                idc_sbc or idc_sbci or sbiw_st or
                                idc_cp or idc_cpc or idc_cpi or
                idc_and or idc_andi or idc_or or idc_ori or idc_eor or idc_com or idc_neg or
                idc_inc or idc_dec or idc_lsr or idc_ror or idc_asr or sreg_bop_wr_en(2);
 
sreg_v_wr_en <= idc_add or idc_adc or adiw_st or idc_sub  or idc_subi or -- idc_adiw
                idc_sbc or idc_sbci or sbiw_st or idc_neg or idc_com or  -- idc_sbiw
                idc_inc or idc_dec or
                                idc_cp or idc_cpc or idc_cpi or
                idc_lsr or idc_ror or idc_asr or sreg_bop_wr_en(3) or
                                idc_and or idc_andi or idc_or or idc_ori or idc_eor; -- V-flag bug fixing
 
sreg_s_wr_en <= idc_add or idc_adc or adiw_st or idc_sub or idc_subi or
                idc_sbc or idc_sbci or sbiw_st or
                                idc_cp or idc_cpc or idc_cpi or
                                idc_and or idc_andi or idc_or or idc_ori or idc_eor or idc_com or idc_neg or
                                idc_inc or idc_dec or idc_lsr or idc_ror or idc_asr or sreg_bop_wr_en(4);
 
sreg_h_wr_en <= idc_add or idc_adc or idc_sub  or idc_subi or
                                idc_cp or idc_cpc or idc_cpi or
                idc_sbc or idc_sbci or idc_neg or sreg_bop_wr_en(5);
 
sreg_t_wr_en <=  idc_bst or sreg_bop_wr_en(6);
 
sreg_i_wr_en <= irq_st1 or reti_st3 or sreg_bop_wr_en(7); -- WAS "irq_start"
 
sreg_fl_in <=  bit_pr_sreg_out when (idc_bst or idc_bclr or idc_bset)='1' else                     -- TO THE SREG
reti_st3&'0'&alu_h_flag_out&alu_s_flag_out&alu_v_flag_out&alu_n_flag_out&alu_z_flag_out&alu_c_flag_out;
 
-- #################################################################################################################
 
-- *********************************************************************************************
-- ************** INSTRUCTION DECODER OUTPUTS FOR THE OTHER BLOCKS  ****************************
-- *********************************************************************************************
 
-- FOR ALU
 
idc_add_out   <= idc_add;
idc_adc_out   <= idc_adc;
idc_adiw_out  <= idc_adiw;
idc_sub_out   <= idc_sub;
idc_subi_out  <= idc_subi;
idc_sbc_out   <= idc_sbc;
idc_sbci_out  <= idc_sbci;
idc_sbiw_out  <= idc_sbiw;
adiw_st_out   <= adiw_st;
sbiw_st_out   <= sbiw_st;
idc_and_out   <= idc_and;
idc_andi_out  <= idc_andi;
idc_or_out    <= idc_or;
idc_ori_out   <= idc_ori;
idc_eor_out   <= idc_eor;
idc_com_out   <= idc_com;
idc_neg_out   <= idc_neg;
idc_inc_out   <= idc_inc;
idc_dec_out   <= idc_dec;
idc_cp_out    <= idc_cp;
idc_cpc_out   <= idc_cpc;
idc_cpi_out   <= idc_cpi;
idc_cpse_out  <= idc_cpse;
idc_lsr_out   <= idc_lsr;
idc_ror_out   <= idc_ror;
idc_asr_out   <= idc_asr;
idc_swap_out  <= idc_swap;
 
-- FOR THE BIT PROCESSOR
sbi_st_out   <= sbi_st;
cbi_st_out   <= cbi_st;
idc_bst_out  <= idc_bst;
idc_bset_out <= idc_bset;
idc_bclr_out <= idc_bclr;
idc_sbic_out <= idc_sbic;
idc_sbis_out <= idc_sbis;
idc_sbrs_out <= idc_sbrs;
idc_sbrc_out <= idc_sbrc;
idc_brbs_out <= idc_brbs;
idc_brbc_out <= idc_brbc;
idc_reti_out <= idc_reti;
 
-- POST INCREMENT/PRE DECREMENT FOR THE X,Y,Z REGISTERS
post_inc <= idc_psinc;
pre_dec  <= idc_prdec;
reg_h_wr <= (idc_st_x or idc_st_y or idc_st_z or idc_ld_x or idc_ld_y or idc_ld_z) and (idc_psinc or idc_prdec);
 
reg_h_adr(0)<= idc_st_x or idc_ld_x;
reg_h_adr(1)<= idc_st_y or idc_std_y or idc_ld_y or idc_ldd_y;
reg_h_adr(2)<= idc_st_z or idc_std_z or idc_ld_z or idc_ldd_z;
 
-- STACK POINTER CONTROL
sp_ndown_up <= idc_pop or idc_ret or (ret_st1 and not cpuwait) or idc_reti or (reti_st1 and not cpuwait); -- ?????????
sp_en <= idc_push or idc_pop or idc_rcall or (rcall_st1 and not cpuwait) or idc_icall or (icall_st1 and not cpuwait) or
idc_ret or (ret_st1 and not cpuwait) or idc_reti or (reti_st1 and not cpuwait) or
call_st1 or (call_st2 and not cpuwait) or irq_st1 or (irq_st2 and not cpuwait); --????????
 
 
branch  <= dex_condition;
bit_num_r_io <= cbi_sbi_bit_num_tmp when (cbi_st or sbi_st)='1' else dex_bitop_bitnum;
 
adr <= adr_int;
 
ramre <= ramre_int;
ramwe <= ramwe_int;
 
iore <= iore_int;
iowe <= iowe_int;
 
--dbusout <= dbusout_int;
 
-- Sleep Control
sleepi <= idc_sleep;
irqok  <= irq_int;
 
-- Watchdog
wdri <= idc_wdr;
 
-- ************************** JTAG OCD support ************************************
 
-- Change of flow       
change_flow <= '0';
valid_instr <= '0';
 
 
end RTL;
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[/] [avr_hp/] [trunk/] [rtl/] [rtl_orig/] [pm_fetch_dec.vhd] - Blame information for rev 2

Line No.	Rev	Author	Line
1	2	tobil	`--************************************************************************************************`
2			`-- PM_FETCH_DEC(internal module) for AVR core`
3			`-- Version 2.6! (Special version for the JTAG OCD)`
4			`-- Designed by Ruslan Lepetenok 14.11.2001`
5			`-- Modified 31.05.06`
6			`-- Modification:`
7			`-- Registered ramre/ramwe outputs`
8			`-- cpu_busy logic modified(affects RCALL/ICALL/CALL instruction interract with interrupt)`
9			`-- SLEEP and CLRWDT instructions support was added`
10			`-- V-flag bug fixed (AND/ANDI/OR/ORI/EOR)`
11			`-- V-flag bug fixed (ADIW/SBIW)`
12			`-- Unused outputs(sreg_bit_num[2..0],idc_sbi_out,idc_cbi_out,idc_bld_out) were removed.`
13			`-- Output alu_data_d_in[7..0] was removed.`
14			`-- Gloabal clock enable(cp2en) was added`
15			`-- cpu_busy(push/pop) + irq bug was fixed 14.07.05`
16			`-- BRXX+IRQ interaction was modified -> cpu_busy`
17			`-- LDS/STS now requires only two cycles for execution (13.01.06 -> last modificatioon)`
18			`--************************************************************************************************`
19
20			`library IEEE;`
21			`use IEEE.std_logic_1164.all;`
22			`use IEEE.std_logic_unsigned.all;`
23
24			`use WORK.AVRuCPackage.all;`
25
26			`entity pm_fetch_dec is port(`
27			`-- Clock and reset`
28			`cp2 : in std_logic;`
29			`cp2en : in std_logic;`
30			`ireset : in std_logic;`
31			`-- JTAG OCD support`
32			`valid_instr : out std_logic;`
33			`insert_nop : in std_logic;`
34			`block_irq : in std_logic;`
35			`change_flow : out std_logic;`
36			`-- Program memory`
37			`pc : out std_logic_vector (15 downto 0);`
38			`inst : in std_logic_vector (15 downto 0);`
39			`-- I/O control`
40			`adr : out std_logic_vector (5 downto 0);`