GT11_INIT_RX.rtl Architecture Reference

Initialization logic for RocketIO RX. More...

Inheritance diagram for GT11_INIT_RX.rtl:

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Collaboration diagram for GT11_INIT_RX.rtl:

[legend]

List of all members.

Functions
string	ExtendString ( string_in: in string , string_len: in integer )
	extend a string
Processes
PROCESS_169	( CLK , START_INIT )
	Sync START_INIT.
PROCESS_170	( CLK )
	Sync LOCK.
PROCESS_171	( CLK )
	Sync PCS_ERROR.
PROCESS_172	( CLK )
	Counter for holding PMA reset for an amount of C_DELAY_PMA_RESET.
PROCESS_173	( CLK )
PROCESS_174	( CLK )
	Counter for holding SYNC for an amount of C_DELAY_SYNC.
PROCESS_175	( CLK )
	Counter for holding PCS reset for an amount of C_DELAY_PCS_RESET.
PROCESS_176	( CLK )
	Counter for waiting C_DELAY_WAIT_PCS after de-assertion of PCS reset.
PROCESS_177	( CLK )
	Counter for PCS error.
PROCESS_178	( CLK )
	Counter for the READY signal.
PROCESS_179	( CLK )
	GT11 Initialization FSM reset.
PROCESS_180	( reset_r(0) , pma_reset_done_i , init_fsm_wait_lock_check , lock_r , sync_done_i , pcs_reset_done_i , wait_pcs_done_i , pcs_error_r1 , pcs_error_count_done_i , wait_ready_done_i )
Components
FDE
	component FDE
SRL16E
	component SRL16
FDRE
	component FDRE
Constants
C_DELAY_PMA_RESET	unsigned ( 2 downto 0 ) := " 011 "
	3
C_DELAY_SYNC	unsigned ( 7 downto 0 ) := " 01000000 "
	64
C_DELAY_PCS_RESET	unsigned ( 2 downto 0 ) := " 011 "
	3
C_DELAY_LOCK	unsigned ( 4 downto 0 ) := " 10000 "
	16
C_DELAY_WAIT_PCS	unsigned ( 3 downto 0 ) := " 0101 "
	5
C_DELAY_WAIT_READY	unsigned ( 7 downto 0 ) := " 01000000 "
	64
C_PCS_ERROR_COUNT	unsigned ( 4 downto 0 ) := " 10000 "
	16
C_RESET	unsigned ( 7 downto 0 ) := " 00000001 "
	GT11 Initialization FSM state encoding.
C_PMA_RESET	unsigned ( 7 downto 0 ) := " 00000010 "
	GT11 Initialization FSM state encoding.
C_WAIT_LOCK	unsigned ( 7 downto 0 ) := " 00000100 "
	GT11 Initialization FSM state encoding.
C_SYNC	unsigned ( 7 downto 0 ) := " 00001000 "
	GT11 Initialization FSM state encoding.
C_PCS_RESET	unsigned ( 7 downto 0 ) := " 00010000 "
	GT11 Initialization FSM state encoding.
C_WAIT_PCS	unsigned ( 7 downto 0 ) := " 00100000 "
	GT11 Initialization FSM state encoding.
C_ALMOST_READY	unsigned ( 7 downto 0 ) := " 01000000 "
	GT11 Initialization FSM state encoding.
C_READY	unsigned ( 7 downto 0 ) := " 10000000 "
	GT11 Initialization FSM state encoding.
Signals
reset_r	unsigned ( 1 downto 0 )
lock_r	std_logic
lock_r2	std_logic
pcs_error_r1	std_logic
pcs_error_r2	std_logic
pma_reset_count_r	unsigned ( 2 downto 0 )
sync_count_r	unsigned ( 7 downto 0 )
pcs_reset_count_r	unsigned ( 2 downto 0 )
wait_pcs_count_r	unsigned ( 3 downto 0 )
pcs_error_count_r	unsigned ( 4 downto 0 )
wait_ready_count_r	unsigned ( 7 downto 0 )
init_state_r	unsigned ( 7 downto 0 )
init_next_state_r	unsigned ( 7 downto 0 )
init_fsm_name	unsigned ( 40 *7 downto 0 )
init_fsm_wait_lock_check	std_logic
pma_reset_done_i	std_logic
lock_pulse_i	std_logic
stage_1_enable_i	std_logic
stage_2_enable_i	std_logic
stage_3_enable_i	std_logic
lockupdate_ready_i	std_logic
shift_register_1_enable_i	std_logic
shift_register_2_enable_i	std_logic
shift_register_3_enable_i	std_logic
shift_register_0_d_i	std_logic
shift_register_1_d_i	std_logic
shift_register_2_d_i	std_logic
shift_register_3_d_i	std_logic
shift_register_0_q_i	std_logic
shift_register_1_q_i	std_logic
shift_register_2_q_i	std_logic
shift_register_3_q_i	std_logic
sync_done_i	std_logic
pcs_reset_done_i	std_logic
wait_pcs_done_i	std_logic
pcs_error_count_done_i	std_logic
wait_ready_done_i	std_logic
tied_to_ground_i	std_logic
tied_to_vcc_i	std_logic
not_lock_i	std_logic
Component Instantiations
shift_register_0	SRL16E
flop_stage_0	FDE
	extra FF for last stage
shift_register_1	SRL16E
	SRL16 Stage One - Second stage of shifting.
flop_stage_1	FDE
	extra FF last stage
shift_register_2	SRL16E
	SRL16 Stage Two - Third stage of shifting.
flop_stage_2	FDE
	extra FF last stage
shift_register_3	SRL16E
flop_stage_3	FDRE
	extra FF last stage

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Detailed Description

Initialization logic for RocketIO RX.

Definition at line 76 of file gt11_init_rx.vhd.

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Member Function Documentation

[Function]

string ExtendString		( string_in in string ,
		string_len in integer )

extend a string

Definition at line 212 of file gt11_init_rx.vhd.

  function ExtendString (string_in  : string;
                         string_len : integer) 
    return string is
    variable string_out : string(1 to string_len) := (others => ' ');

  begin
    if string_in'length > string_len then
      string_out := string_in(1 to string_len);
    else
      string_out(1 to string_in'length) := string_in;
    end if;
    return string_out;
  end ExtendString;

[Process]

PROCESS_169		( CLK ,
		START_INIT )

Sync START_INIT.

Definition at line 235 of file gt11_init_rx.vhd.

  process (CLK, START_INIT)
  begin
    if (START_INIT = '1') then
      reset_r <= "11";
    elsif (rising_edge(CLK)) then
      reset_r <= '0' & reset_r(1);
    end if;
  end process;

[Process]

PROCESS_170

( CLK )

Sync LOCK.

Definition at line 245 of file gt11_init_rx.vhd.

  process(CLK)
  begin
    if(CLK'event and CLK = '1') then
      if (reset_r(0) = '1') then
        lock_r <= '0';
      else
        lock_r <= LOCK;
      end if;
    end if;
  end process;

[Process]

PROCESS_171

( CLK )

Sync PCS_ERROR.

Definition at line 257 of file gt11_init_rx.vhd.

  process(CLK)
  begin
    if(CLK'event and CLK = '1') then
      if(reset_r(0) = '1') then
        pcs_error_r1 <= '0';
      else
        pcs_error_r1 <= PCS_ERROR;
      end if;
    end if;
  end process;

[Process]

PROCESS_172

( CLK )

Counter for holding PMA reset for an amount of C_DELAY_PMA_RESET.

Definition at line 275 of file gt11_init_rx.vhd.

  process(CLK)
  begin
    if(CLK'event and CLK = '1') then
      if(init_state_r /= C_PMA_RESET) then
        pma_reset_count_r <= C_DELAY_PMA_RESET;
      else
        pma_reset_count_r <= pma_reset_count_r - 1;
      end if;
    end if;
  end process;

[Process]

PROCESS_173

( CLK )

Create a pulse from RXLOCK to initialize SRL16's. Need to register the LOCK signal from the GT11 twice since the LOCK is based on REFCLK

Definition at line 299 of file gt11_init_rx.vhd.

    process(CLK)
    begin
      if(CLK'event and CLK = '1') then
        if (reset_r(0) = '1') then
          lock_r2 <= '0';
        else
          lock_r2 <= lock_r;
        end if;
      end if;
    end process;

[Process]

PROCESS_174

( CLK )

Counter for holding SYNC for an amount of C_DELAY_SYNC.

Definition at line 443 of file gt11_init_rx.vhd.

  process(CLK)
  begin
    if(CLK'event and CLK = '1') then
      if(init_state_r /= C_SYNC) then
        sync_count_r <= C_DELAY_SYNC;
      else
        sync_count_r <= sync_count_r - 1;
      end if;
    end if;
  end process;

[Process]

PROCESS_175

( CLK )

Counter for holding PCS reset for an amount of C_DELAY_PCS_RESET.

Definition at line 457 of file gt11_init_rx.vhd.

  process(CLK)
  begin
    if(CLK'event and CLK = '1') then
      if(init_state_r /= C_PCS_RESET) then
        pcs_reset_count_r <= C_DELAY_PCS_RESET;
      else
        pcs_reset_count_r <= pcs_reset_count_r - 1;
      end if;
    end if;
  end process;

[Process]

PROCESS_176

( CLK )

Counter for waiting C_DELAY_WAIT_PCS after de-assertion of PCS reset.

Definition at line 471 of file gt11_init_rx.vhd.

  process(CLK)
  begin
    if(CLK'event and CLK = '1') then
      if(init_state_r /= C_WAIT_PCS) then
        wait_pcs_count_r <= C_DELAY_WAIT_PCS;
      else
        wait_pcs_count_r <= wait_pcs_count_r - 1;
      end if;
    end if;
  end process;

[Process]

PROCESS_177

( CLK )

Counter for PCS error.

Definition at line 485 of file gt11_init_rx.vhd.

  process(CLK)
  begin
    if(CLK'event and CLK = '1') then
      if(init_state_r = C_PMA_RESET) then
        pcs_error_count_r <= C_PCS_ERROR_COUNT;
      elsif (((init_state_r = C_ALMOST_READY) or (init_state_r = C_READY)) and (pcs_error_r1 and lock_r) = '1') then
        pcs_error_count_r <= pcs_error_count_r - 1;
      end if;
    end if;
  end process;

[Process]

PROCESS_178

( CLK )

Counter for the READY signal.

Definition at line 499 of file gt11_init_rx.vhd.

  process(CLK)
  begin
    if(CLK'event and CLK = '1') then
      if((init_state_r /= C_ALMOST_READY) or (pcs_error_r1 = '1')) then
        wait_ready_count_r <= C_DELAY_WAIT_READY;
      elsif(pcs_error_r1 = '0') then
        wait_ready_count_r <= wait_ready_count_r - 1;
      end if;
    end if;
  end process;

[Process]

PROCESS_179

( CLK )

GT11 Initialization FSM reset.

Definition at line 513 of file gt11_init_rx.vhd.

  process (CLK)
  begin
    if (rising_edge(CLK)) then
      if (reset_r(0) = '1') then
        init_state_r <= C_RESET;
      else
        init_state_r <= init_next_state_r;
      end if;
    end if;
  end process;

[Process]

PROCESS_180		( reset_r(0) ,
		pma_reset_done_i ,
		init_fsm_wait_lock_check ,
		lock_r ,
		sync_done_i ,
		pcs_reset_done_i ,
		wait_pcs_done_i ,
		pcs_error_r1 ,
		pcs_error_count_done_i ,
		wait_ready_done_i )

GT11 Initialization FSM - This FSM is used to initialize the GT11 block asserting the PMA and PCS reset in sequence. It also takes into account of any error that may happen during initialization. The block uses USRCLK as reference for the delay. DO NOT use the output of the GT11 clocks for this reset module, as the output clocks may change when reset is applied to the GT11. Use a system clock, and make sure that the wait time for each state equals the specified number of USRCLK cycles.

The following steps are applied:

1. C_RESET: Upon system reset of this block, PMA reset will be asserted
2. C_PMA_RESET: PMA reset is held for 3 USRCLK cycles
3. C_WAIT_LOCK: Wait for LOCK. After LOCK is asserted, wait for 16 LOCKUPDATE cycles and wait for the USRCLK of the GT11s to be stabled before going to the next state to assert the PCS reset. If LOCK gets de-asserted, we reset the counter and wait for LOCK again.
4. C_SYNC: Assert SYNG for 64 SYNC cycles. If LOCK gets de-asserted, we go back to Step 3.
5. C_PCS_RESET: Assert PCS reset for 3 USRCLK cycles. If LOCK gets de-asserted, we go back to Step 3.
6. C_WAIT_PCS: After de-assertion of PCS reset, wait 5 USRCLK cycles. If LOCK gets de-asserted, we go back to Step 3.
7. C_ALMOST_READY: Go to the Almost Ready state. If LOCK gets de-asserted, we go back to Step 3. If there is a PCS error (i.e. buffer error) detected while LOCK is high, we go back to Step 4. If we cycle PCS reset for an N number of C_PCS_ERROR_COUNT, we go back to Step 1 to do a PMA reset.
8. C_READY: Go to the Ready state. We reach this state after waiting 64 USRCLK cycles without any PCS errors. We assert the READY signal to denote that this block finishes initializing the GT11. If there is a PCS error during this state, we go back to Step 4. If LOCK is lost, we go back to Step 3.

Definition at line 557 of file gt11_init_rx.vhd.

  process (reset_r(0), pma_reset_done_i, init_fsm_wait_lock_check, lock_r,
           sync_done_i, pcs_reset_done_i, wait_pcs_done_i, pcs_error_r1,
           pcs_error_count_done_i, wait_ready_done_i)
    variable init_fsm_name : string(1 to 25);
  begin
    case init_state_r is
      
      when C_RESET =>
        
        if (reset_r(0) = '1') then
          init_next_state_r <= C_RESET;
        else
          init_next_state_r <= C_PMA_RESET;
        end if;
        init_fsm_name := ExtendString("C_RESET", 25);

      when C_PMA_RESET =>

        if (pma_reset_done_i = '1') then
          init_next_state_r <= C_WAIT_LOCK;
        else
          init_next_state_r <= C_PMA_RESET;
        end if;
        init_fsm_name := ExtendString("C_PMA_RESET", 25);

      when C_WAIT_LOCK =>
        
        if(init_fsm_wait_lock_check = '1') then
          init_next_state_r <= C_SYNC;
        else
          init_next_state_r <= C_WAIT_LOCK;
        end if;
        init_fsm_name := ExtendString("C_WAIT_LOCK", 25);

      when C_SYNC =>
        if (lock_r = '1') then
          if (sync_done_i = '1') then
            init_next_state_r <= C_PCS_RESET;
          else
            init_next_state_r <= C_SYNC;
          end if;
        else
          init_next_state_r <= C_PMA_RESET;  --C_WAIT_LOCK;
        end if;
        init_fsm_name := ExtendString("C_SYNC", 25);

      when C_PCS_RESET =>
        if (lock_r = '1') then
          if (pcs_reset_done_i = '1') then
            init_next_state_r <= C_WAIT_PCS;
          else
            init_next_state_r <= C_PCS_RESET;
          end if;
        else
          init_next_state_r <= C_PMA_RESET;  --C_WAIT_LOCK;
        end if;
        init_fsm_name := ExtendString("C_PCS_RESET", 25);

      when C_WAIT_PCS =>
        if (lock_r = '1') then
          if (wait_pcs_done_i = '1') then
            init_next_state_r <= C_ALMOST_READY;
          else
            init_next_state_r <= C_WAIT_PCS;
          end if;
        else
          init_next_state_r <= C_PMA_RESET;  --C_WAIT_LOCK;
        end if;
        init_fsm_name := ExtendString("C_WAIT_PCS", 25);

      when C_ALMOST_READY =>
        if (lock_r = '0') then
          init_next_state_r <= C_PMA_RESET;  --C_WAIT_LOCK;
        elsif ((pcs_error_r1 = '1') and (pcs_error_count_done_i = '0')) then
          init_next_state_r <= C_SYNC;
        elsif ((pcs_error_r1 = '1') and (pcs_error_count_done_i = '1')) then
          init_next_state_r <= C_PMA_RESET;
        elsif (wait_ready_done_i = '1') then
          init_next_state_r <= C_READY;
        else
          init_next_state_r <= C_ALMOST_READY;
        end if;
        init_fsm_name := ExtendString("C_ALMOST_READY", 25);

      when C_READY =>
        if ((lock_r = '1') and (pcs_error_r1 = '0')) then
          init_next_state_r <= C_READY;
        elsif ((lock_r = '1') and (pcs_error_r1 = '1')) then
          init_next_state_r <= C_PCS_RESET;
        else
          init_next_state_r <= C_PMA_RESET;  --C_WAIT_LOCK;
        end if;
        init_fsm_name := ExtendString("C_READY", 25);

      when others =>
        init_next_state_r <= C_RESET;
        init_fsm_name     := ExtendString("C_RESET", 25);

    end case;
  end process;

---

Member Data Documentation

C_ALMOST_READY unsigned ( 7 downto 0 ) := " 01000000 " [Constant]

GT11 Initialization FSM state encoding.

Definition at line 111 of file gt11_init_rx.vhd.

C_DELAY_LOCK unsigned ( 4 downto 0 ) := " 10000 " [Constant]

16

Definition at line 91 of file gt11_init_rx.vhd.

C_DELAY_PCS_RESET unsigned ( 2 downto 0 ) := " 011 " [Constant]

3

Definition at line 89 of file gt11_init_rx.vhd.

C_DELAY_PMA_RESET unsigned ( 2 downto 0 ) := " 011 " [Constant]

3

Definition at line 85 of file gt11_init_rx.vhd.

C_DELAY_SYNC unsigned ( 7 downto 0 ) := " 01000000 " [Constant]

64

Definition at line 87 of file gt11_init_rx.vhd.

C_DELAY_WAIT_PCS unsigned ( 3 downto 0 ) := " 0101 " [Constant]

5

Definition at line 93 of file gt11_init_rx.vhd.

C_DELAY_WAIT_READY unsigned ( 7 downto 0 ) := " 01000000 " [Constant]

64

Definition at line 95 of file gt11_init_rx.vhd.

C_PCS_ERROR_COUNT unsigned ( 4 downto 0 ) := " 10000 " [Constant]

16

Definition at line 97 of file gt11_init_rx.vhd.

C_PCS_RESET unsigned ( 7 downto 0 ) := " 00010000 " [Constant]

GT11 Initialization FSM state encoding.

Definition at line 107 of file gt11_init_rx.vhd.

C_PMA_RESET unsigned ( 7 downto 0 ) := " 00000010 " [Constant]

GT11 Initialization FSM state encoding.

Definition at line 101 of file gt11_init_rx.vhd.

C_READY unsigned ( 7 downto 0 ) := " 10000000 " [Constant]

GT11 Initialization FSM state encoding.

Definition at line 113 of file gt11_init_rx.vhd.

C_RESET unsigned ( 7 downto 0 ) := " 00000001 " [Constant]

GT11 Initialization FSM state encoding.

Definition at line 99 of file gt11_init_rx.vhd.

C_SYNC unsigned ( 7 downto 0 ) := " 00001000 " [Constant]

GT11 Initialization FSM state encoding.

Definition at line 105 of file gt11_init_rx.vhd.

C_WAIT_LOCK unsigned ( 7 downto 0 ) := " 00000100 " [Constant]

GT11 Initialization FSM state encoding.

Definition at line 103 of file gt11_init_rx.vhd.

C_WAIT_PCS unsigned ( 7 downto 0 ) := " 00100000 " [Constant]

GT11 Initialization FSM state encoding.

Definition at line 109 of file gt11_init_rx.vhd.

FDE [Component]

component FDE

Definition at line 161 of file gt11_init_rx.vhd.

FDRE [Component]

component FDRE

Definition at line 195 of file gt11_init_rx.vhd.

flop_stage_0 FDE [Component Instantiation]

extra FF for last stage

Definition at line 336 of file gt11_init_rx.vhd.

flop_stage_1 FDE [Component Instantiation]

extra FF last stage

Definition at line 364 of file gt11_init_rx.vhd.

flop_stage_2 FDE [Component Instantiation]

extra FF last stage

Definition at line 395 of file gt11_init_rx.vhd.

flop_stage_3 FDRE [Component Instantiation]

extra FF last stage

Definition at line 431 of file gt11_init_rx.vhd.

shift_register_0 SRL16E [Component Instantiation]

Counter for the LOCKUPDATE cycles for RXLOCK: This is built with SRL16s. Currently, we need to wait for 16 LOCKUPDATE cycles to qualify the RXLOCK signal. Each LOCKUPDATE = 1024 REFCLK cycles. In this module, we assume 1 REFCLK = 1 USRCLK (please adjust the address of the fourth SRL16 stage as neccessary). The whole four stages give 16,304 cycles of delay (16 * 16 * 16 * 4); note that the last stage has an extra FF at the end.

Definition at line 322 of file gt11_init_rx.vhd.

shift_register_1 SRL16E [Component Instantiation]

SRL16 Stage One - Second stage of shifting.

Definition at line 350 of file gt11_init_rx.vhd.

shift_register_2 SRL16E [Component Instantiation]

SRL16 Stage Two - Third stage of shifting.

Definition at line 381 of file gt11_init_rx.vhd.

shift_register_3 SRL16E [Component Instantiation]

SRL16 Stage Three - Fourth stage of shifting LOCKUPDATE ready is redundant here in resetting the SRL16 since the flop is already reset by RXLOCK from the MGT

Definition at line 415 of file gt11_init_rx.vhd.

SRL16E [Component]

component SRL16

Definition at line 176 of file gt11_init_rx.vhd.

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The documentation for this class was generated from the following file:

• gt11_init_rx.vhd