dsata.vhd

Vhdl cod for a bus.For sp2e

            IF (tmp_time > MIN_COMWAKE_SPACE) AND (tmp_time < MAX_COMWAKE_SPACE) THEN
                comwake_space_ok <= '1';
            END IF;
        ELSIF rising_edge(rx_idle) THEN
            space_start := NOW;
            tmp_time := NOW - burst_start;
            cominit_space_ok <= '0';
            comwake_space_ok <= '0';                            
        END IF;         
    END PROCESS;

    ----------------------------------------------------------------------------
    -- OOB signals, COMINIT and COMWAKE, detection                            --
    ----------------------------------------------------------------------------                   
    OOB_INIT : PROCESS
    VARIABLE cnt : INTEGER := 0;
    VARIABLE align_cnt : INTEGER := 0;
    BEGIN                       
        IF cnt > 7 THEN
            COMRESET <= '1';
           END IF; 
        WAIT UNTIL align = '1';
        align_cnt := 1;
        FOR i IN 1 TO 3 LOOP
               WAIT UNTIL align = '1' FOR 40 * RXPERIOD;
            IF align = '1' THEN
                align_cnt := align_cnt + 1;
             ELSE 
                 EXIT;
             END IF;
         END LOOP;    
        IF align_cnt = 4 THEN
            cnt := cnt + 1;
            WAIT UNTIL cominit_space_ok = '1' FOR MAX_COMINIT_SPACE;
            IF cominit_space_ok = '1' THEN
                cnt := cnt + 1;
                align_cnt := 0;
               ELSE
                cnt := 0;           
                COMRESET <= '0';
                align_cnt := 0;
            END IF;
        ELSE
            cnt := 0;           
            COMRESET <= '0';
            align_cnt := 0;
        END IF;
    END PROCESS OOB_INIT;

    OOB_WAKE : PROCESS
    VARIABLE cnt : INTEGER := 0;
    VARIABLE align_cnt : INTEGER := 0;
    BEGIN                       
        IF cnt > 7 THEN
            COMWAKE <= '1';
           END IF; 
        WAIT UNTIL align = '1';
        align_cnt := 1;
        FOR i IN 1 TO 3 LOOP
               WAIT UNTIL align = '1' FOR 40 * RXPERIOD;
            IF align = '1' THEN
                align_cnt := align_cnt + 1;
             ELSE 
                 EXIT;
             END IF;
         END LOOP;    
        IF align_cnt = 4 THEN
            cnt := cnt + 1;
            WAIT UNTIL comwake_space_ok = '1' FOR MAX_COMWAKE_SPACE;
            IF comwake_space_ok = '1' THEN
                cnt := cnt + 1;
                align_cnt := 0;
               ELSE
                cnt := 0;           
                COMWAKE <= '0';
            END IF;
        ELSE
            cnt := 0;           
            COMWAKE <= '0';
        END IF;
    END PROCESS OOB_WAKE;



    ----------------------------------------------------------------------------
    -- Receiver shift register and fixed pattern detection - ALIGN            --
    ----------------------------------------------------------------------------                   
    RX_SHIFT : PROCESS(RXclk)   
    VARIABLE rx_bit_cnt : INTEGER := 0;
    VARIABLE rx_word_cnt : INTEGER := 0;
    VARIABLE align_detection : std_logic_vector(39 DOWNTO 0);
    VARIABLE RX_buffer : rx_buffer_type; 
    VARIABLE RX_shift_reg : std_logic_vector(9 DOWNTO 0) := "0000000000";
    BEGIN                
        IF falling_edge(RXclk) THEN    
              RX_shift_reg(8 DOWNTO 0) := RX_shift_reg(9 DOWNTO 1);               
              RX_shift_reg(9) := RX_int;
               rx_bit_cnt := rx_bit_cnt + 1;   
               IF rx_bit_cnt = 10 THEN
                   rx_bit_cnt := 0;
                   RX_buffer(rx_word_cnt) := RX_shift_reg;
                   rx_word_cnt := rx_word_cnt + 1;    
                   IF RX_shift_reg = cK285(0) OR RX_shift_reg = cK285(1) THEN
                       COMMA <= '1';              
                       rx_word_cnt := 1;
                       RX_buffer(0) := RX_shift_reg;
                   ELSIF RX_shift_reg = cK283(0) OR RX_shift_reg = cK283(1) THEN
                       rx_word_cnt := 1;
                       RX_buffer(0) := RX_shift_reg;
                   ELSIF RX_shift_reg = cK285(0) OR RX_shift_reg = cK285(1) THEN
                       rx_word_cnt := 1;
                       RX_buffer(0) := RX_shift_reg;
                   ELSIF rx_word_cnt = 4 THEN                  
                       COMMA <= '0';                    
                      rx_word_cnt := 0;     
                      IF RX_buffer(0) /= cK285(0) AND RX_buffer(0) /= cK285(1) THEN
                           RXCLOCK <= '1', '0' AFTER 20*RXPERIOD;
                       END IF;

                       DATAOUT <= RX_buffer(3) & RX_buffer(2) & RX_buffer(1) & RX_buffer(0);
                    IF ((RX_buffer(3) & RX_buffer(2) & RX_buffer(1) & RX_buffer(0)) = ALIGN_RDpos) OR 
                    ((RX_buffer(3) & RX_buffer(2) & RX_buffer(1) & RX_buffer(0)) = ALIGN_RDneg) THEN
                        align_ctrl <= '1';         
                    ELSE
                        align_ctrl <= '0';            
                    END IF;                   
                    
                    
                   END IF;
               END IF;    

--               -- align pattern detection
               align_detection(38 DOWNTO 0) := align_detection(39 DOWNTO 1);
               align_detection(39) := RX_int;
            IF (align_detection = ALIGN_RDpos) OR (align_detection = ALIGN_RDneg) THEN
                align <= '1', '0' AFTER RXPERIOD; 
                rx_bit_cnt := 0;
                rx_word_cnt := 0;                
            ELSE
                align <= '0';            
            END IF;                   
            
        END IF;    
    END PROCESS RX_SHIFT;

    ----------------------------------------------------------------------------
    -- Transmit clock                                                         --
    ----------------------------------------------------------------------------                   
    TXclk <= NOT(TXclk) AFTER TXPERIOD/2;
 
    ----------------------------------------------------------------------------
    -- Transmitter shift register                                             --
    ----------------------------------------------------------------------------                   
    
    TX_SHIFT : PROCESS(TXclk, PHYRESET, COMRESET)   
    VARIABLE tx_cnt : INTEGER := 0;     
    BEGIN                  
        IF rising_edge(PHYRESET) OR rising_edge(COMRESET) THEN
            tx_cnt := 0;
            TX_shift_reg_empty <= '1';
            TX_shift_rdy <= '1';                                
        ELSIF rising_edge(TXclk) THEN
            TX_shift_rdy <= '0';  
            IF TX_ld = '1' THEN
                   tx_cnt := 9;
                TX_shift_reg <= TX_reg;
                TX_shift_reg_empty <= '0';     
            ELSIF tx_cnt > 2 THEN
                   TX_shift_reg(8 DOWNTO 0) <= TX_shift_reg(9 DOWNTO 1);
                tx_cnt := tx_cnt - 1;
            ELSIF tx_cnt = 2 THEN
                   TX_shift_reg(8 DOWNTO 0) <= TX_shift_reg(9 DOWNTO 1);
                   tx_cnt := tx_cnt - 1;
                TX_shift_rdy <= '1';            
            ELSIF tx_cnt = 1 THEN 
                   tx_cnt := tx_cnt - 1;            
                   TX_shift_reg(8 DOWNTO 0) <= TX_shift_reg(9 DOWNTO 1);  
                   TX_shift_rdy <= '1';
            ELSIF tx_cnt = 0 THEN 
                TX_shift_reg_empty <= '1';
                TX_shift_rdy <= '1';                    
            END IF;    
        END IF;    
    END PROCESS TX_SHIFT;

    TXp <= TX_shift_reg(0) WHEN (TX_shift_reg_empty = '0') ELSE '0';
    TXn <= NOT TX_shift_reg(0) WHEN (TX_shift_reg_empty = '0') ELSE '0';

    ----------------------------------------------------------------------------
    -- Data transfer                                                          --
    ----------------------------------------------------------------------------                   

    DATA_TRANS : PROCESS
    BEGIN                                                   
        WAIT ON TXclk;--transmit_cominit, transmit_comwake, transmit_align, transmit_link_data;
        IF transmit_cominit = '1' AND transmit_cominit_end = '0' THEN
--            WAIT UNTIL TXclk = '1';
        cominit_loop : LOOP
            FOR i IN 0 TO 3 LOOP
                SendAlign(TX_shift_rdy, TXclk, TX_ld, TX_reg);
                WAIT UNTIL TXclk = '1';
                EXIT cominit_loop WHEN (RESET = '1' OR COMRESET = '1');
            END LOOP;
            WAIT UNTIL TX_shift_reg_empty = '1';
            WAIT UNTIl RESET ='1' OR COMRESET = '1' FOR 480 * TXPERIOD;
            EXIT cominit_loop WHEN (RESET = '1' OR COMRESET = '1');
            FOR i IN 0 TO 3 LOOP
                SendAlign(TX_shift_rdy, TXclk, TX_ld, TX_reg);
                WAIT UNTIL TXclk = '1';
                EXIT cominit_loop WHEN (RESET = '1' OR COMRESET = '1');
            END LOOP;
            WAIT UNTIL TX_shift_reg_empty = '1';
            WAIT UNTIl RESET ='1' OR COMRESET = '1' FOR 480 * TXPERIOD;
            EXIT cominit_loop WHEN (RESET = '1' OR COMRESET = '1');
            FOR i IN 0 TO 3 LOOP
                SendAlign(TX_shift_rdy, TXclk, TX_ld, TX_reg);
                WAIT UNTIL TXclk = '1';
                EXIT cominit_loop WHEN (RESET = '1' OR COMRESET = '1');
            END LOOP;
            WAIT UNTIL TX_shift_reg_empty = '1';
            WAIT UNTIl RESET ='1' OR COMRESET = '1' FOR 480 * TXPERIOD;
            EXIT cominit_loop WHEN (RESET = '1' OR COMRESET = '1');
            FOR i IN 0 TO 3 LOOP
                SendAlign(TX_shift_rdy, TXclk, TX_ld, TX_reg);
                WAIT UNTIL TXclk = '1';
                EXIT cominit_loop WHEN (RESET = '1' OR COMRESET = '1');
            END LOOP;
            WAIT UNTIL TX_shift_reg_empty = '1';
            WAIT FOR 480 * TXPERIOD;
            FOR i IN 0 TO 3 LOOP
                SendAlign(TX_shift_rdy, TXclk, TX_ld, TX_reg);
                WAIT UNTIL TXclk = '1';
                EXIT cominit_loop WHEN (RESET = '1' OR COMRESET = '1');
            END LOOP;
            WAIT UNTIL TX_shift_reg_empty = '1';
            WAIT UNTIl RESET ='1' OR COMRESET = '1' FOR 480 * TXPERIOD;
            EXIT cominit_loop WHEN (RESET = '1' OR COMRESET = '1');
            FOR i IN 0 TO 3 LOOP
                SendAlign(TX_shift_rdy, TXclk, TX_ld, TX_reg);
                WAIT UNTIL TXclk = '1';
                EXIT cominit_loop WHEN (RESET = '1' OR COMRESET = '1');
            END LOOP;
            WAIT UNTIL TX_shift_reg_empty = '1';
            WAIT UNTIl RESET ='1' OR COMRESET = '1' FOR MAX_COMINIT_SPACE;
            EXIT cominit_loop WHEN (RESET = '1' OR COMRESET = '1');
--            WAIT FOR MAX_COMINIT_SPACE;
            transmit_cominit_end <= '1', '0' AFTER 40 * RXPERIOD;
            WAIT UNTIL TXclk = '1';
--            transmit_cominit_end <= '0';
            EXIT;
        END LOOP;
        END IF;
        IF transmit_comwake = '1' AND transmit_comwake_end = '0' THEN   
        comwake_loop: LOOP
--            WAIT UNTIL TXclk = '1';        
            FOR i IN 0 TO 3 LOOP
                SendAlign(TX_shift_rdy, TXclk, TX_ld, TX_reg);
                WAIT UNTIL TXclk = '1';
                EXIT comwake_loop WHEN (RESET = '1' OR COMRESET = '1');
            END LOOP;
            WAIT UNTIL TX_shift_reg_empty = '1';
            WAIT FOR 160 * TXPERIOD;
            FOR i IN 0 TO 3 LOOP
                SendAlign(TX_shift_rdy, TXclk, TX_ld, TX_reg);
                EXIT comwake_loop WHEN (RESET = '1' OR COMRESET = '1');
                WAIT UNTIL TXclk = '1';
            END LOOP;
            WAIT UNTIL TX_shift_reg_empty = '1';
            WAIT UNTIl RESET ='1' OR COMRESET = '1' FOR 160 * TXPERIOD;
            EXIT comwake_loop WHEN (RESET = '1' OR COMRESET = '1');
            FOR i IN 0 TO 3 LOOP
                SendAlign(TX_shift_rdy, TXclk, TX_ld, TX_reg);
                EXIT comwake_loop WHEN (RESET = '1' OR COMRESET = '1');
                WAIT UNTIL TXclk = '1';
            END LOOP;
            WAIT UNTIL TX_shift_reg_empty = '1';
            WAIT FOR 160 * TXPERIOD;
            FOR i IN 0 TO 3 LOOP
                SendAlign(TX_shift_rdy, TXclk, TX_ld, TX_reg);
                EXIT comwake_loop WHEN (RESET = '1' OR COMRESET = '1');
                WAIT UNTIL TXclk = '1';
            END LOOP;
            WAIT UNTIL TX_shift_reg_empty = '1';
            WAIT UNTIl RESET ='1' OR COMRESET = '1' FOR 160 * TXPERIOD;
            EXIT comwake_loop WHEN (RESET = '1' OR COMRESET = '1');
            FOR i IN 0 TO 3 LOOP
                SendAlign(TX_shift_rdy, TXclk, TX_ld, TX_reg);
                EXIT comwake_loop WHEN (RESET = '1' OR COMRESET = '1');
                WAIT UNTIL TXclk = '1';
            END LOOP;
            WAIT UNTIL TX_shift_reg_empty = '1';